Dissertations / Theses: 'Brotes de plantas'

1

Maureira, Espinosa Yenifert. "Aplicación de sanitizantes en brotes de alfalfa (Medicago sativa L.) conservados bajo atmósfera modificada." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/111118.

Full text

Abstract:

Memoria para optar al título profesional de Ingeniero Agrónomo Mención Agroindustria
El objetivo de este estudio fue evaluar el efecto de distintos sanitizantes como hipoclorito de sodio (NaClO 100 mg L-1), dióxido de cloro (ClO2 5 y 10 mg L-1), ácido peroxiacético (APA 50 y 90 mg L-1) y clorito de sodio acidificado (CSA 250 y 500 mg L-1) sobre la carga microbiana y calidad sensorial en brotes de alfalfa envasados en atmósfera modificada pasiva conservados a 5º C por 7 días. En dos ensayos independientes se emplearon las mismas dosis de sanitizantes, pero diferentes bolsas con diferente permeabilidad a los gases. Los parámetros evaluados fueron respiración, concentración de gases en el interior de las bolsas, color, carga microbiana y calidad sensorial. El uso de bolsas de baja permeabilidad utilizadas en el Ensayo I, junto con las dosis de sanitizantes no fue efectivo para mantener la calidad sensorial de los brotes de alfalfa. Las concentraciones alcanzadas al interior de las bolsas fueron de 18,2 a 27% de CO2 y 1 a 1,2% de O2 tras 7 días. En todos los tratamientos se obtuvo una reducción de los recuentos en aerobios mesófilos, psicrófilos y enterobacterias al utilizar los distintos sanitizantes. El CSA 250 y 500 presentaron los recuentos más bajos, sin embargo afectaron negativamente el color, y calidad sensorial de los brotes. En el Ensayo II, las concentraciones al interior de las bolsas fueron de 2,7 a 4,1% de CO2 y 3,6 a 6,7% de O2 y al igual que el Ensayo I, el CSA 500 fue el sanitizante que presentó los menores recuentos en aerobios mesófilos, enterobacterias y psicrófilos con 4,6, 4,8 y 5,5 log ufc g-1, respectivamente, seguido por CSA 250 con 5,4, 5,3 y 5,7 log ufc g-1, respectivamente, sin afectar las características sensoriales. En ambos ensayos fue el NaClO (Bp) el tratamiento que registró recuentos más altos en mesófilos y enterobacterias, lo que confirmaría que el envasado en AM mantiene mejor la calidad microbiológica que el envasado en contacto con el aire. Por tanto los brotes de alfalfa lavados con CSA 250 y 500 en combinación con un envasado en atmósfera modificada diminuyeron la carga microbiana sin afectar la calidad sensorial, manteniéndose dentro de la media aceptable durante los 7 días a 5º C.
The objective of this study was to evaluate the effect of different sanitizers as sodium hypochlorite (NaClO 100 mg L -1 ), chlorine dioxide (ClO2 5 and 10 mg L -1 ), peroxyacetic acid (APA 50 and 90 mg L -1 ) and acidified sodium chlorite (ASC 250 and 500 mg L -1 ) on the microbial and sensory quality in packaged alfalfa sprouts passive modified atmosphere maintained at 5° C for 7 days. In two independent assays the same doses of sanitizers, and bags with different permeability to gases were used. The parameters evaluated were breathing, gas concentration inside the bags, color, microbial load and sensory quality. The use of low permeability bags used in the assay I, along with doses of sanitizers was not effective to maintain the sensory quality of alfalfa sprouts. Concentrations achieved within the bags were 18.2 to 27% CO2 and 1 to 1.2% O2 after 7 days. In all treatments a reduction in aerobic plate counts, mesofilos, psychrofiles and enterobacteriaceae using different sanitizers was observed. The CSA 250 and 500 showed the lowest counts, but affected negatively the color and sensory quality of sprouts. In assay II, the concentrations inside the bags were from 2.7 to 4.1% CO2 and 3.6 to 6.7% O2 and just that the assay I, CSA 500 was the sanitizer that presented the lower aerobic plate counts, enterobacteriaceae and psychrophiles with 4.6, 4.8 and 5.5 log CFU g -1 respectively, followed by CSA 250 with 5.4, 5.3 and 5.7 log cfu g -1 respectively, without affecting the sensory characteristics. In both assays was the NaClO (BP) treatment to higher counts recorded plate and Enterobacteriaceae, which would confirm that the packaging AM maintains the microbiological quality better than the packaging in contact with air. So alfalfa sprouts washed with CSA 250 and 500 in combination with modified atmosphere packaging decreases the microbial load without affecting the sensory quality, while remaining within acceptable average for 7 days at 5º C.

APA, Harvard, Vancouver, ISO, and other styles

2

Soto, Toro Daniela Alejandra. "Efecto de distintos sanitizantes en las características funcionales y microbiológicas en brotes de alfalfa bajo condiciones de atmósfera modificada." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/112330.

Full text

Abstract:

Ingeniero Agrónomo
En este estudio se evaluó, el efecto de distintos sanitizantes en brotes de alfalfa almacenados y refrigerados a 5 °C, utilizando hipoclorito de sodio en una concentración de 100 mg L-1 (HS 100) como control. En un primer ensayo se utilizó peróxido de hidrógeno (25 y 50 mg L-1; PH 25 y PH 50), ácido láctico (8,5 y 17 mg L-1; AL 8,5 y AL 17) y ácido cítrico (5000 y 10000 mg L-1; AC 5000 y AC 10000). Posteriormente los brotes se almacenaron bajo atmósfera modificada con valores de 6,7 - 13,7% de O2 y 1,9 - 3,5% de CO2 durante 12 días a 5 °C. Para el segundo ensayo se escogieron las concentraciones de los sanitizantes más efectivas para controlar el crecimiento microbiano, sin alterar la calidad sensorial. De esta forma se seleccionaron el peróxido de hidrógeno, ácido láctico y ácido cítrico (50, 17 y 5000 y 10000 mg L-1, respectivamente). Los productos tratados con estos sanitizantes fueron almacenados durante 7 días y refrigerados a 5 °C. Los tratamientos con AL (8,5 y 17 mg L-1) fueron efectivos en reducir la carga microbiana de los brotes hasta el quinto día de almacenamiento, posteriormente los recuentos aumentaron sin diferencias entre tratamientos. La apariencia, sabores extraños, color y turgencia de los brotes de alfalfa se afectó por los tratamientos con PH (25 y 50 mg L-1) y con AL (8,5 y 17 mg L-1). Por el contrario, con AC (5000 y 10000 mg L-1) y el tratamiento control (HS 100) fueron evaluados positivamente por los jueces en el análisis de calidad sensorial. En el ensayo II, a pesar de la alta carga microbiana inicial, el tratamiento AL 17 fue efectivo en cuanto a la reducción microbiológica de los brotes de alfalfa, logrando una reducción de 3,0 log ufc g-1 de microorganismos psicrófilos; sin embargo, éste fue evaluado negativamente por el panel sensorial, cuya apariencia el primer día de evaluación fue calificada como “deficiente”. A diferencia de los tratamientos AC 5000 y AC 10000, los cuales a pesar de ser efectivos para mantener la calidad sensorial, no fueron capaces de reducir las poblaciones microbianas de los brotes de alfalfa. PH 50, AL 17, AC (5000 y 10000) y el tratamiento control, disminuyeron el contenido de fenoles totales y actividad antioxidante en el tiempo, sin mayores diferencias entre tratamientos; sin embargo, el tratamiento control HS 100 fue el menos afectado en cuanto a la disminución del contenido de fenoles total (0,2 mg EAG, Equivalentes de Ácido Gálico, g-1 de peso fresco), pero se observó una disminución significativa de la actividad antioxidante (0,9 mg ET, Equivalentes de Trolox, g-1 de peso fresco) desde el inicio, hasta el final de la conservación a 5 °C.
In this research, the effects of different sanitizers on alfalfa sprouts stored at 5 °C were evaluated, using sodium hypochlorite at 100 mg L-1 (HS 100) as control. The first assay was comprised of the application of hydrogen peroxide (25 and 50 mg L-1; PH 25 and PH 50), lactic acid (8,5 and 17 mg L-1; AL 8,5 and AL 17) and citric (5000 y 10000 mg L-1; AC 5000 and AC 10000). After that, the sprouts were stored under modified atmosphere with values of 6,7 – 13,7% of O2 and 1,9 – 3,5% of CO2 during 12 days at 5 °C. For the second assay, the concentrations of the most effective treatments regarding to microbiological growth without affecting sensory attributes in alfalfa sprouts were chosen, where hydrogen peroxide, lactic acid and citric acid (50, 17 and 5000 and 10000 mg L-1, respectively) were selected. The product treated with these sanitizers were stored at 5 °C for 7 days. Treatments with AL (8,5 and 17 mg L-1) were effective in reducing the microbial load of the sprouts up to the fifth day of storage, subsequently the counts increased without differences between treatments. Treatments with PH (25 and 50 mg L-1) and lactic acid (8,5 and 17 mg L-1) affected appearance, presence of off flavors, color and turgor on the alfalfa sprouts. On the other hand, with AC (5000 and 10000 mg L-1) and the control (HS 100) treatment were evaluated positively in the sensory quality analysis by judges. In Assay II, in spite of the high initial microbial load, AL 17 treatment was effective in the microbiological reduction of alfalfa sprouts achieving 3,0 log cfu g-1 reductions of psychrophilic microorganisms, nevertheless it was evaluated negatively by the sensory panel, due to the appearance on the first day of evaluation was graded as "deficient". Eventhough the treatments AC (5000 and 10000) were effective to preserve the sensory quality, they were not able to reduce the microbial populations of alfalfa sprouts. PH 50, AL 17, AC (5000 and 10000) and control treatment, decreased the content of total phenols and antioxidant activity along the shelf life, without significantly statistical differences among them, nevertheless the HS 100 control treatment was less affected in decreasing the total phenols content (0,2 mg GAE, Gallic Acid Equivalent, g-1 of fresh weight), on the contrary a significantly decrease of antioxidant activity (0,9 mg ET, Trolox Equivalent, g-1 of fresh weight) was observed from the beginning, to the end of the shelf life period at 5 °C.

APA, Harvard, Vancouver, ISO, and other styles

3

Crisóstomo, Vega María José. "Características funcionales y microbiológicas en brotes de alfalfa (Medicago sativa L.) tratados con diferentes sanitizantes." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/116076.

Full text

Abstract:

Memoria para optar al título profesional de: Ingeniero Agrónomo Mención Agroindustria
No autorizada por el autor para ser publicada a texto completo
En este estudio se evaluó el efecto de los agentes sanitizantes sobre la calidad funcional y microbiológica en los brotes de alfalfa (Medicago sativa L.). Los brotes fueron sumergidos durante 5 minutos en soluciones sanitizantes de hipoclorito de sodio (HS; 100 mg L-1), ácido peroxiacético (APA; 90 mg L-1), dióxido de cloro (DC; 10 mg L-1) y clorito de sodio acidificado (CSA; 500 mg L-1), que luego fueron envasados en bolsas plásticas (60 g) y almacenados a 5 °C durante 7 a 8 días. Los parámetros evaluados fueron: tasa respiratoria, atmósfera modificada, luminosidad (L), croma (C*), tono (Hab), fenoles totales, capacidad antioxidante, análisis microbiológicos y sensoriales. Los brotes de alfalfa lavados en las soluciones sanitizantes presentaron un aumento en la tasa respiratoria en todos los tratamientos. El hipoclorito de sodio, ácido peroxiacético y dióxido de cloro no afectaron el parámetro de color ni la calidad sensorial. Sin embargo, el clorito de sodio acidificado registró un leve pardeamiento y menores valores en calidad sensorial. El menor recuento microbiológico durante el tiempo de almacenamiento lo obtuvo el clorito de sodio acidificado, alcanzando una reducción promedio de 1,3 log UFC g-1. El contenido de fenoles totales y la capacidad antioxidante presentaron un leve aumento durante el almacenamiento a 5 °C, pero sin diferencias significativas entre los tratamientos.

APA, Harvard, Vancouver, ISO, and other styles

4

Tardón, Machuca Alejandro Antonio. "Efecto de la radiación UV-C sobre la calidad en brotes de alfalfa (medicago sativa L.) conservados en atmósferas modificadas." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/112331.

Full text

Abstract:

Memoria para optar al título profesional de Ingeniero Agrónomo
La industria de hortalizas mínimamente procesadas en fresco (MPF) utiliza comúnmente lavados con hipoclorito de sodio (NaClO) para disminuir la carga microbiana del producto, sin embargo, éste genera subproductos perjudiciales para la salud. Por esto, la necesidad de encontrar nuevas tecnologías emergentes y sostenibles como la radiación UV-C. El presente trabajo tuvo como objetivo evaluar el efecto de la aplicación de diferentes dosis de radiación UV-C sobre la calidad de brotes de alfalfa envasados en atmósfera modificada. Se realizaron dos ensayos utilizando bolsas de baja y alta permeabilidad. Los brotes fueron lavados con agua potable y tratados con UV-C en dosis de 0,35, 5,26, 10,18, 15,09 y 20,01 kJ m-2. Tras la aplicación del tratamiento UV-C, los brotes se envasaron en atmósfera modificada y se almacenaron a 5 °C por 8 días. Como testigo se utilizaron brotes lavados con NaClO (100 mg L-1) y envasados de la misma forma. Se evaluó la tasa respiratoria, composición gaseosa al interior de las bolsas, color, análisis microbiológico y sensorial. La combinación de radiación UV-C con bolsas de baja permeabilidad no fue efectiva para mantener la calidad en los brotes de alfalfa. La tasa respiratoria de los brotes no se vio afectada por las dosis de radiación utilizadas. La concentración gaseosa al interior de las bolsas registró valores de 19 a 23% CO2 y 1,5% para O2 tras 8 días, no influyendo las distintas dosis de radiación utilizadas. Los tratamientos con NaClO y en especial el tratamiento en bolsa perforada, reflejaron un menor pardeamiento en comparación a los tratamientos con dosis elevadas de UV-C (15,09 y 20,01 kJ m-2). El tratamiento con dosis de 20,01 kJ m-2 obtuvo los recuentos más elevados en mésofilos y psicrófilos, mientras que en enterobacterias, Lactobacillus, además de hongos y levaduras no existieron diferencias entre los distintos tratamientos, no obstante los conteos se encontraron dentro de los límites permitidos. La calidad sensorial de los brotes no registró diferencias significativas entre los tratamientos, sin embargo presentaron un deterioro evidente fuera de los límites de aceptabilidad fijados, teniendo un potencial de almacenamiento no superior a 4 o 5 días. Las bolsas de alta permeabilidad en conjunto con la aplicación de radiación UV-C, fueron efectivas para mantener la calidad general en brotes de alfalfa. La tasa respiratoria no se vio afectada por las distintas dosis de radiación utilizada. Al interior de las bolsas, se registraron concentraciones gaseosas de 2 a 3% para CO2 y 4 a 8% para O2 luego de 8 días. La radiación UV-C permitió mantener el color de los brotes, registrando diferencias sólo los tratamientos 10,18 y 20,01 kJ m-2 que presentaron un color más intenso (mayor C*), mientras que la L y Hab se mantuvieron sin diferencias significativas. Las dosis (15,09 y 20,01 kJ m-2) proporcionaron un control efectivo sobre el crecimiento de mesófilos, psicrófilos, enterobacterias, además de hongos y levaduras, mientras que dosis bajas y medias de radiación registraron conteos más elevados. Las distintas dosis de radiación UVC permitieron mantener la calidad sensorial de los brotes. La apariencia y turgencia se mantuvieron dentro de los rangos “más que regular” a “buena”, la intensidad de color dentro del rangos “bueno” a “muy bueno” y la presencia de sabores extraños dentro de los rangos “sin sabor” a “muy suave”, dentro de los límites permitidos.
The minimally processed fresh vegetables (MPF) industry commonly uses sodium hypochlorite (NaClO) washings to reduce the microbial load. However, it generates harmful by-products to health. Therefore, it is necessary to study new emerging and sustainable technologies such as the UV-C radiation. The aim of this study was to evaluate the effect of applying different UV-C radiation doses on the quality of germinated alfalfa in modified atmosphere packaging. Two trials were conducted using low and high permeability bags. The germinated alfalfa was washed with water and treated with 0.35, 5.26, 10.18, 15.09 and 20.01 kJ m-2 UV-C doses. Then, the germinated alfalfa was packed in modified atmosphere and stored at 5 °C for 8 d. Control outbreaks were washed with NaClO (100 mg L-1) and packaged in the same way. The respiration rate, atmosphere composition, colour, microbiological and sensory quality were evaluated. The combination of UV-C radiation with low permeability bags was not effective in maintaining the germinated alfalfa quality. The respiration rate was not affected by the UVC radiation doses. The atmosphere composition inside the bags showed values ranging from 19 to 23% CO2 and 1.5% O2 after 8 d, but it was not influenced by the different UV-C radiation doses. The treatments with NaClO and specially the treatment in perforated bag showed less enzymatic browning compared to germinated alfalfa treated with high UV-C doses (15.09 and 20.01 kJ m-2). Treatment with 20.01 kJ m-2 doses reported the highest counts for mesophilic and psycrophilic microorganisms, while enterobacteria, Lactobacillus, yeasts and fungi did not show significantly statistical differences between treatments and the values were within the legal permitted limits. The sensory quality of the germinated alfalfa did not differ significantly between treatments, but showed a clear deterioration beyond the set limits for acceptability, having a storage potential no longer than 4 or 5 d. The bags of high permeability in conjunction with UV-C radiation were effective in maintaining the overall quality of germinated alfalfa. The respiration rate was not affected by the UV-C radiation doses. The internal atmosphere composition was 2 to 3% CO2 and 4 to 8% O2 after 8 d. Treatments with UV-C radiation doses at 10.18 and 20.01 kJ m-2 allowed the outbreak colour to be preserved. However, germinated alfalfa treated at 20.01 kJ m-2 had a deeper colour (higher C*), while L and Hab stayed without statistical significantly differences. Doses at 15.09 and 20.01 kJ m-2 provided an effective growth control for mesophilic, psycrophilic, enterobacteria, fungi and yeasts, while low and medium UV-C radiation doses reported higher counts. Different UV-C radiation doses maintained the sensory quality of germinated alfalfa. Grades for appearance and turgidity ranged from "rather than regular" to "good", while colour intensity was graded as "good" to "very good" and off flavours ranged from "no flavour" to "too soft", within the set permitted limits.

APA, Harvard, Vancouver, ISO, and other styles

5

Peña, Palominos Lorena Andrea. "Efecto de la radiación gamma sobre brotes de ciruelo europeo (Prunnus domestica L.) Var. D'agen cultivados in vitro." Tesis, Universidad de Chile, 2006. http://www.repositorio.uchile.cl/handle/2250/101832.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Flores, Pino Paulina Alondra. "Efecto de la temperatura de almacenamiento sobre la tasa respiratoria y calidad de germinados de alfalfa mínimamente procesados en fresco." Tesis, Universidad de Chile, 2013. http://repositorio.uchile.cl/handle/2250/147926.

Full text

Abstract:

Memoria para optar al título profesional de: Ingeniero Agrónomo Mención: Agroindustria
El objetivo de este estudio fue evaluar el efecto de distintas temperaturas de almacenamiento (0, 5 y 8 ºC), sobre la tasa respiratoria y calidad sensorial de germinados de alfalfa (Medicago sativa L.) mínimamente procesados. Estos fueron lavados con agua potable a 5 ºC, secados y envasados en tarrinas de polietileno (PE), posteriormente fueron almacenados durante 6 y 8 días (95% de humedad relativa). Los parámetros medidos fueron: tasa respiratoria, color, sólidos solubles totales, acidez titulable y calidad sensorial. En ambos ensayos se observó una tendencia a la disminución de la tasa respiratoria a lo largo del almacenamiento, para todos los tratamientos. El tratamiento 0 ºC, presentó tasas significativamente más bajas en comparación a los otros dos tratamientos, con valores de 13,9 a 27,6 mg CO2 · kg-1 · h-1 en el ensayo 1 y de 19,2 a 39,8 mg CO2 · kg-1 · h-1 en el ensayo 2. El tratamiento 5 ºC registró tasas entre 23,1 y 45,1 mg CO2 · kg-1 · h-1 y 21,4 a 58,6 mg CO2 · kg-1 · h-1 en el ensayo 1 y 2 respectivamente. El tratamiento 8 ºC, presentó tasas significativamente mayores registrándose rangos entre 30,2 y 47,0 mg CO2 · kg-1 · h-1 en el ensayo 1 y 38,1 a 88,2 mg CO2 · kg-1 · h-1 en el ensayo 2. Con respecto a la evolución del color, en el ensayo 1 el tratamiento 0 ºC presentó menores valores de croma y tono, es decir, se observó un producto menos pardeado, con respecto a los otros tratamientos, registrándose valores promedio de croma en un rango 11,6 a 12,9 y tono entre 94 a 93,4. En el ensayo 2, sólo se observaron menores valores para el parámetro de tono para el mismo tratamiento, registrándose valores promedio entre 93,5 y 92,9. Se observaron aumentos significativos en la acidez a lo largo de los días de almacenamiento para los tres tratamientos, en el ensayo 1. En cuanto a la evolución de la calidad sensorial, se observaron diferencias en el ensayo 1, en los parámetros apariencia e intensidad de color, el tratamiento mejor evaluado fue el almacenado a 8 ºC. En el ensayo 2, el tratamiento 8 ºC fue el mejor evaluado en cuanto a apariencia, en cambio, fue el peor evaluado en cuanto a presencia de olores extraños.
The aim of this study was to evaluate the effect of different storage temperatures (0, 5 and 8 °C) on respiratory rate and sensory quality of alfalfa sprouts (Medicago sativa L.) minimally processed. The sprouts were washed with water at 5 °C, dried and packed in polyethylene (PE) trays, then were stored for 6 and 8 days (95% relative humidity). The parameters measured were: respiratory rate, color, total soluble solids, titratable acidity (TA) and sensory quality. Both trials showed a decrease in respiratory rate during the storage for all treatments. Treatment of 0 °C showed significantly lower rates as compared to the others two treatments with values of 13.9 to 27.6 mg CO2 · kg-1 · h-1 for trial 1 and 19.2 to 39.8 mg CO2 · kg-1 · h-1 for trial 2. Treatment at 5 °C reached 23.1 to 45.1 mg CO2 · kg-1 · h -1 and 21.4 to 58.6 mg CO2 · kg-1 · h-1, during trials 1 and 2 respectively. Treatment at 8 ºC, showed significantly higher rates, recording ranges from 30.2 to 47.0 mg CO2 · kg-1 · h-1 in trial 1 and 38.1 to 88.2 mg CO2 · kg-1 · h-1 in trial 2. Significant increases in the percentage of TA along storage days for the three treatments, in trial 1. Regarding the evolution of sensory quality, differences were observed in trial 1, appearance and intensity parameters of color, were the higher score was at 8 °C, compared to others. In trial 2, treatment at 8 ºC was the best evaluated for appearance, however, was the worst evaluated for the presence of off odour.

APA, Harvard, Vancouver, ISO, and other styles

7

Herrera, Matos Salónida Beatriz. "Efecto protector del champú conteniendo extracto etanólico de corteza y brotes tiernos de Colletia spinosissima J. Gmelin (TACSANA) sobre la irritación inducida en piel de ratas." Master's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/6470.

Full text

Abstract:

Evalúa el efecto protector del champú conteniendo extracto etanólico de corteza y brotes tiernos de Colletia spinosissima J. Gmelin (tacsana), en la irritación inducida en la piel de ratas. Es un estudio experimental, desarrollado en el laboratorio de Farmacología de la Facultad de Farmacia y Bioquímica, Universidad Mayor de San Marcos, Lima-Perú. Utiliza 30 ratas Holtzman (15 hembras y 15 machos), en un peso promedio de 142 - 100 g; asignados en forma aleatoria en cinco grupos de estudio: champú I 50 mg/kg, champú II 250 mg/kg, champú III 500 mg de Colletia spinosissima, champú comercial y champú base (control). En el extracto se determinó la presencia de metabolitos secundario: saponinas, taninos, flavonoides, alcaloides, carbohidratos. Resultados: in vivo se demostró la actividad protectora antiinflamatoria de la planta (50%), p< 0,05 y cicatrizante (50%) p < 0,05 en la piel de ratas, comprobado mediante estudios histológicos de la piel, y sin dermosensibilización, con la formación de fibras de colágeno; reparación de tejidos epiteliales y desaparición de los signos inflamatorios. In vitro se ha observado que la planta en 1 ug/mL induce una reducción del radical DPPH de 71,02%, comparativamente a vitamina C (27,53%) y al trolox (66,93%). Concluye que el extracto etanólico de la corteza y brotes tiernos de Colletia spinosissima presenta efectos antiinflamatorios y cicatrizantes sobre la piel de ratas, siendo mejor en dosis de 500 mg/kg; es antioxidante in vitro con mayor actividad que vitamina C y Trolox; no presenta toxicidad en ratas.
Tesis

APA, Harvard, Vancouver, ISO, and other styles

8

Herrera, Matos Salónida Beatriz, and Matos Salónida Beatriz Herrera. "Efecto protector del champú conteniendo extracto etanólico de corteza y brotes tiernos de Colletia spinosissima J. Gmelin (TACSANA) sobre la irritación inducida en piel de ratas." Master's thesis, Universidad Nacional Mayor de San Marcos, 2017. http://cybertesis.unmsm.edu.pe/handle/cybertesis/6470.

Full text

Abstract:

Evalúa el efecto protector del champú conteniendo extracto etanólico de corteza y brotes tiernos de Colletia spinosissima J. Gmelin (tacsana), en la irritación inducida en la piel de ratas. Es un estudio experimental, desarrollado en el laboratorio de Farmacología de la Facultad de Farmacia y Bioquímica, Universidad Mayor de San Marcos, Lima-Perú. Utiliza 30 ratas Holtzman (15 hembras y 15 machos), en un peso promedio de 142 - 100 g; asignados en forma aleatoria en cinco grupos de estudio: champú I 50 mg/kg, champú II 250 mg/kg, champú III 500 mg de Colletia spinosissima, champú comercial y champú base (control). En el extracto se determinó la presencia de metabolitos secundario: saponinas, taninos, flavonoides, alcaloides, carbohidratos. Resultados: in vivo se demostró la actividad protectora antiinflamatoria de la planta (50%), p< 0,05 y cicatrizante (50%) p < 0,05 en la piel de ratas, comprobado mediante estudios histológicos de la piel, y sin dermosensibilización, con la formación de fibras de colágeno; reparación de tejidos epiteliales y desaparición de los signos inflamatorios. In vitro se ha observado que la planta en 1 ug/mL induce una reducción del radical DPPH de 71,02%, comparativamente a vitamina C (27,53%) y al trolox (66,93%). Concluye que el extracto etanólico de la corteza y brotes tiernos de Colletia spinosissima presenta efectos antiinflamatorios y cicatrizantes sobre la piel de ratas, siendo mejor en dosis de 500 mg/kg; es antioxidante in vitro con mayor actividad que vitamina C y Trolox; no presenta toxicidad en ratas.
Tesis

APA, Harvard, Vancouver, ISO, and other styles

9

Aravena, Córdova Andree Gerard. "Evaluación del efecto de manejos de poda y enmiendas al suelo sobre el potencial hídrico de los brotes de olivos (Olea europaea L.) sometidos a déficit hídrico absoluto en la Región de Coquimbo." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/150915.

Full text

Abstract:

Memoria para optar al título profesional de Ingeniero Agrónomo
Debido a la sequía que ha afectado a la Región de Coquimbo en los últimos años, se decidió estudiar el efecto de manejos de poda y de enmiendas al suelo en huertos de olivo de la variedad Arbequina sometidos a sequía absoluta, durante la temporada 2012-2013, en la localidad de Tabalí, Región de Coquimbo, Chile.

APA, Harvard, Vancouver, ISO, and other styles

10

Aravena, Córdova Andree Gerard. "Evaluación del efecto de las maniobras de poda y enmiendas al suelo sobre el potencial hídrico de los brotes de olivos (Olea europaea L.) Sometidos un déficit hídrico absoluto en la Región de Coquimbo." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/147621.

Full text

Abstract:

Memoria para optar al título profesional de: Ingeniero Agrónomo.
Debido a la sequía que ha afectado a la Región de Coquimbo en los últimos años, se decidió estudiar el efecto de manejos de poda y de enmiendas al suelo en huertos de olivo de la variedad Arbequina sometidos a sequía absoluta, durante la temporada 2012-2013, en la localidad de Tabalí, Región de Coquimbo, Chile. Las plantas se escogieron bajo una condición hídrica similar, a las cuales se les aplicaron diferentes tratamientos establecidos por dos factores evaluados, poda (sin poda y con poda) y enmienda (sin enmienda, enmiendas de compost, de ácido húmico y de estiércol). Posterior a la aplicación de los tratamientos (febrero), se interrumpió el riego y se realizaron mediciones periódicas hasta después de la primera lluvia (junio). Se midieron propiedades físicas del suelo antes y después de la aplicación de las enmiendas para determinar el efecto que tuvieron dichas aplicaciones, sumado a ello, se midieron parámetros fisiológicos como el potencial hídrico de brote, la conductancia estomática, y la fotosíntesis. Durante la temporada, se observó que las enmiendas disminuyeron significativamente el estrés de las plantas de olivo, induciendo potenciales hídricos de brote (Ψb) menos negativos luego de cuatro meses de aplicadas en el suelo. Se observó que el estiércol disminuyó la densidad aparente, el ácido húmico mejoró la estructura del suelo y que la realización de poda en conjunto con la enmienda de estiércol aumentaron las tasas de asimilación fotosintética. Además, la poda tuvo un efecto reductor sobre el rendimiento en base a peso fresco de frutos de olivo.
Due to the drought that has affected the Region of Coquimbo the last years, we decided to study the effect of pruning and soil amendments in Arbequina olive orchards submitted to absolute drought during the 2012-2013 season in Tabalí, Coquimbo Region, Chile. The selected plants were under similar moisture conditions and different treatments were applied according to a factorial design with two factors: pruning (without pruning and with pruning) and amendment (without amendment, compost, humic acid and manure). Once treatments were applied (February) irrigation was stopped and periodical measurements were carried out until the first rain (June). Physical soil properties were measured before and after application of the amendments to determine their effects, and physiological parameters such as photosynthesis, stomatal conductance and shoot water potential were also measured. It was noticed that the amendments significantly decreased the stress of olive plants, inducing less negative Ψb four months after the date they were applied. It was observed that manure decreased bulk density, humic acid improved soil structure and pruning, in conjunction with manure amendment, increased photosynthetic assimilation rates. In addition, pruning had a reducing effect on yield based on fresh weight of olive fruits.

APA, Harvard, Vancouver, ISO, and other styles

11

Santos, Vanessa Rebouças dos. "Crescimento, propagação, floração e compostos de reserva em Costus arabicus L." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315649.

Full text

Abstract:

Orientador: Lilian Beatriz Penteado Zaidan
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-13T07:49:31Z (GMT). No. of bitstreams: 1 Santos_VanessaReboucasdos_D.pdf: 832172 bytes, checksum: fd8402411397a7ed317acd370f3b06a3 (MD5) Previous issue date: 2009
Resumo: O mercado mundial da floricultura tem incentivado a introdução e produção de novas plantas tropicais, cujas formas inusitadas, exuberantes e coloridas têm alto potencial ornamental. No Brasil, o cultivo para a produção de flores tropicais vem aumentando, graças às condições ambientais favoráveis, à disponibilidade de terras, água e energia, além da mão de obra relativamente barata, que incidem diretamente na qualidade do produto e possibilitam custos competitivos nos mercados externos. Porém, existem limitações para a expansão de produtos novos, dentre elas, a falta de informação quanto às condições de cultivo intensivo de espécies potenciais e a sua conservação em condições tropicais. As espécies do gênero Costus (Costaceae) vêm despertando grande interesse ornamental devido às suas inflorescências que apresentam beleza e exoticidade. O objetivo do presente trabalho foi estudar o crescimento, a propagação, a floração e os carboidratos de reserva em plantas de Costus arabicus L. cultivadas sob condições de casa de vegetação, com vistas a oferecer conhecimento fisiológico e informações técnicas para o cultivo dessa espécie como planta ornamental. Plantas de C. arabicus foram transplantadas para vasos e mantidas sob condições de casa de vegetação. As plantas foram submetidas a tratamentos fotoperiódicos de 8, 12, 16 e 20 h, avaliando-se o crescimento vegetativo (brotações, hastes, altura e número de folhas) e a floração. Para o estudo da propagação vegetativa, os rizomas de C. arabicus foram divididos em suas regiões distal, mediana e proximal e cultivados em diferentes épocas: plantio realizado em julho (inverno), com as plantas matrizes em estádio prévio à floração; plantio realizado em novembro (primavera), com as plantas matrizes em floração; e plantio realizado em março (outono), com as plantas matrizes em estádio vegetativo. A floração foi avaliada pelo aparecimento de botão floral, pela fase de desenvolvimento da inflorescência, número de flores desenvolvidas e tempo decorrido da antese até a senescência da flor. Foram realizadas análises de amido e carboidratos solúveis (açúcares totais e redutores) do rizoma e foram registradas a massa fresca (MF) e a massa seca (MS) da parte aérea e do rizoma e calculada a razão MF/MS. O delineamento experimental utilizado foi o inteiramente casualizado. As médias dos tratamentos foram comparadas segundo Tukey com 5% de probabilidade. Os resultados indicaram que as variáveis de crescimento analisadas foram influenciadas pelo fotoperíodo e favorecidas por dias longos. De modo geral, a capacidade propagativa do rizoma independe da região utilizada, porém a região proximal favoreceu a formação de brotos, principalmente no verão. Plantas de C. arabicus têm ciclo de desenvolvimento anual, com uma fase de crescimento vegetativo, latência no crescimento na época do inverno e floração entre novembro e abril. Botões florais foram observados em todos os tratamentos fotoperiódicos e, portanto, a indução floral não foi uma resposta qualitativa a esse fator ambiental. Contudo, a resposta de floração, com base nos diversos aspectos avaliados foi favorecida no fotoperíodo de 16 h e em termos quantitativos, fotoperíodo de 8 h foi desfavorável para a floração. A melhor época de plantio visando à floração foi no mês de julho, pois o processo de floração ocorreu após apenas quatro meses de cultivo das plantas, quando comparadas com as plantas obtidas de rizomas cultivados em novembro e março, que levaram aproximadamente 12 e 8 meses, respectivamente, para florescer. O amido foi considerado o principal carboidrato de reserva do rizoma e foi hidrolisado durante o processo de floração, enquanto os açúcares totais foram utilizados como fonte primária de energia para a brotação dos rizomas de plantas de C. arabicus. Os resultados obtidos do crescimento, propagação vegetativa e floração permitem que as plantas de C. arabicus possam ser aproveitadas como plantas ornamentais, visto que suas características morfológicas, como a filotaxia em espiral, a inflorescência esverdeada, as flores brancas com labelo róseo, são aspectos interessantes para o mercado da floricultura.
Abstract: The world market for floriculture is encouraging the introduction and production of new tropical plants, with their unusual forms, exuberant and colorful, with high ornamental potential. In Brazil, the cultivation for production of tropical flowers are increasing due to, favourable environmental factors, availability of land, water, energy and relatively cheap labour which reflects directly on the quality of the products and offers competitive costs in foreign markets. But there are limitations to the expansion of new products, including the misinformation about the conditions of intensive cultivation of new plant species and their potential conservation in tropical conditions. The species of the genus Costus (Costaceae) are attracting great interest because of their ornamental flowers with high beauty and exoticity. The objective of this work was to study propagation, growth, flowering and the reserve compounds in plants of Costus arabicus L. growing under glasshouse conditions, aiming to offer technical information and physiological knowledge for the cultivation of this species as an ornamental plant. Plants of C. arabicus were transplanted to pots and kept under the conditions of a greenhouse. The plants were subjected to photoperiodic treatments of 8, 12, 16 and 20 h. Vegetative growth (shoots, stems, height and number of leaves) and flowering were evaluated. For vegetative propagation, rhizomes of C. arabicus were divided in their distal, middle and proximal regions and were grown in different seasons: planting held in July (winter), when the plants were in a stage prior to flowering; planting held in November (spring), when the plants were flowering and planting held in March (autumn), when the plant were in vegetative stage. Flowering was assessed by the appearance of floral buds, the developmental stage of the inflorescence, the number of flowers developed and elapsed time from anthesis to senescence of the flower. Analysis of soluble starch and carbohydrates (total and reducing carbohydrates) of rhizome were performed. Fresh mass (FM) and dry matter (DM) of the shoot and the rhizome were recorded to calculate the ratio FM/DM. The experimental design was a completely randomized. The averages were compared according to Tukey at 5% probability. The results indicated that the growth of variables analyzed were influenced by photoperiod and favored by long days. In general, the ability of the rhizome to propagate not depends on the region used, but the proximal region favored vegetative growth development, formation of shoots, the development of rods, plant height and number of leaves, mainly on summer. Plants of C. arabicus have annual cycle of development, with a phase of vegetative growth, followed by latency of winter season and flowering between November and April. Floral buds were observed in all photoperiodic treatments, and therefore floral induction was not a qualitative response to this environmental factor. However, the response of flowering, based on the various aspects assessed was favored in the photoperiod of 16 h in quantitative terms, photoperiod of 8 h was unfavorable for flowering. The best season for flowering was when planting is in July, because the process of flowering occurred after only four months of cultivation of the plants, when compared with the plants obtained from rhizomes, cultivated in November and March, which brought about 12 and 8 months, respectively, to flower. Starch was considered the main carbohydrate reserve of rhizome and noted that it was hydrolyzed during the process of flowering, while the total sugar were used as a primary energy source for the sprouting of the rhizomes. The results of growth, vegetative propagation and flowering allow the plants of C. arabicus can be used as ornamental plants since its morphological characteristics, such as spiral phytolaxy, the green inflorescence, and the white flowers with pink labelo, are interesting aspects to the market for floriculture.
Doutorado
Doutor em Biologia Vegetal

APA, Harvard, Vancouver, ISO, and other styles

12

Pereira, Vera Lucia Pupo. "Aproveitamento tecnologico do broto de bambu, Dendrocalamus giganteus munro." reponame:Repositório Institucional da UFSC, 1987. http://repositorio.ufsc.br/xmlui/handle/123456789/75411.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Soares, Luciana Gomes. "Respostas do peróxido de hidrogênio e mentol sobre a fisiologia dos brotos de batata." Universidade Federal de Viçosa, 2018. http://www.locus.ufv.br/handle/123456789/21903.

Full text

Abstract:

Submitted by MARCOS LEANDRO TEIXEIRA DE OLIVEIRA (marcosteixeira@ufv.br) on 2018-09-20T18:19:01Z No. of bitstreams: 1 texto completo.pdf: 791078 bytes, checksum: ded36bb336fca50038b6791c39c9a8a9 (MD5)
Made available in DSpace on 2018-09-20T18:19:01Z (GMT). No. of bitstreams: 1 texto completo.pdf: 791078 bytes, checksum: ded36bb336fca50038b6791c39c9a8a9 (MD5) Previous issue date: 2018-02-24
Conselho Nacional de Desenvolvimento Científico e Tecnológico
O armazenamento adequado da batata (Solanum tuberosum L.) visa manter a qualidade do produto, minimizando a presença de doenças e reduzindo a perda de massa dos tubérculos, garantindo matéria-prima aceitável pela indústria de processamento. A brotação é um dos principais fatores que contribuem para a perda de qualidade levando à remobilização de carboidratos. Neste contexto, uma estratégia para amenizar esse problema de brotação durante o armazenamento é a redução da temperatura, afim de aumentar em longo prazo o tempo de vida útil e a quebra de dormência. Com isso, a aplicação de compostos naturais como supressores de crescimento de brotos, pode ser uma alternativa viável durante o armazenamento. Assim, o objetivo deste trabalho foi avaliar as repostas ao peróxido de hidrogênio e mentol sobre a fisiologia de tubérculos de batata não-dormente. Após a quebra natural da dormência e início da brotação, os tubérculos foram tratados com peróxido de hidrogênio 1:10 (27 % de H 2 O 2 ), mentol (50 %); controle (Água) e H 2 O 2 (1:10) + mentol, e armazenados a 8 oC por 40 dias. Os tratamentos com mentol (Ment) inibiram o crescimento dos brotos, devido a menor perda de massa, comprimento e número de brotações, ao contrário dos efeitos observados pelo peróxido de hidrogênio que induziu o crescimento dos brotos quando comparado ao controle. Em relação ao metabolismo do carbono, os açúcares solúveis totais, açúcares redutores e não-redutores apresentaram variação linear em função do período de armazenamento, não diferindo entre os tratamentos. A atividade das enzimas POD e PPO apresentou aumentos ao longo do período de armazenamento, diferentemente dos compostos fenólicos que obtiveram um declínio durante os 40 dias de avaliação, no entanto, os tratamentos não foram significativos durante este período. Portanto, o óleo essencial de mentol é uma alternativa eficiente na supressão da brotação e na manutenção da qualidade dos tubérculos, ao contrário do peróxido de hidrogênio que, quando aplicado isoladamente, induz a brotação.
Adequate storage of potato (Solanum tuberosum L.) aims to maintain the quality of the product, minimizing the presence of diseases and reduces the loss of tuber mass, guaranteeing raw material acceptable to the processing industry. Sprouting is one of the main factors contributing to the loss of quality leading to the remobilization of carbohydrates. As a strategy to alleviate sprouting during storage is to reduce the temperature in order to increase the long-term shelf-life of the potato and postponing the break of dormancy. Thus, the application of natural compounds as sprout growth suppressants may be a viable alternative during storage. Thus, the objective of this work was to evaluate the responses to hydrogen peroxide and menthol on the physiology of non-dormant potato tubers. After the natural breakage of dormancy and beginning of bud growth, the tubers were treated with hydrogen peroxide 1:10 (27% H 2 O 2 ), menthol (50%); control (water) and H 2 O 2 (1:10) + menthol, and stored at 8 °C for 40 days storage. Menthol treatments (Ment) inhibited the growth of the sprouts, due to lower loss of mass, length and number of shoots, unlike the effects observed by the hydrogen peroxide that induced the growth of the sprout when compared with the control. In relation to the carbon metabolism, the total soluble sugars, reducing and non-reducing sugars presented linear variation as a function of the storage period, not differing among the treatments. The activity of the POD and PPO enzymes showed increases over the storage period, unlike the phenolic compounds that obtained a decline during the 40 days of evaluation, however, the treatments were not significant during this period. Therefore, menthol essential oil is an efficient alternative in suppressing sprouting and maintaining tuber quality, unlike the hydrogen peroxide that when applied alone induced sprouting.

APA, Harvard, Vancouver, ISO, and other styles

14

Watanabe, Lucas Bertoldi. "Desenvolvimento e caracterização de pasta de broto de bambu (Dendrocalamus asper)." reponame:Repositório Institucional da UFSC, 2016. https://repositorio.ufsc.br/xmlui/handle/123456789/168292.

Full text

Abstract:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Ciência dos Alimentos, Florianópolis, 2016.
Made available in DSpace on 2016-09-20T05:10:52Z (GMT). No. of bitstreams: 1 340770.pdf: 1117803 bytes, checksum: 52b3ead72fe631db621877c9c552560e (MD5) Previous issue date: 2016
Os brotos de bambu, amplamente consumidos pelos povos asiáticos, são ainda relativamente desconhecidos e pouco valorizados no Brasil. O presente trabalho teve por objetivo geral desenvolver e caracterizar um novo produto, em forma de pasta, a partir do broto de bambu da espécie Dendrocalamus asper. A presença de glicosídeos cianogênicos na matéria prima leva à necessidade do estabelecimento de um protocolo para o pré-processamento dos brotos, bem como de análises qualitativas (testes rápidos) e quantitativas para cianeto, sendo este um dos objetivos específicos deste trabalho. Os demais dizem respeito às características físico-químicas, microbiológicas, de textura e cor da pasta de broto de bambu. A formulação da pasta não comprometeu as características do broto de bambu, como um alimento com baixo teor de gordura, incorporou proteína e manteve a presença de fibras solúveis e insolúveis. Quanto ao teor de minerais, o sódio, potássio e cálcio foram relativamente mantidos, exceto pela adição de sódio, porém em valores significativamente inferiores à maioria dos produtos industrializados. A presença de compostos fenólicos e atividade antioxidante da pasta, mesmo considerando um produto com alto teor de umidade, justificam o seu consumo. Quanto a sua obtenção, os resultados das análises microbiológicas indicaram a pasta como apta para consumo, logo após a produção e durante a estocagem. As características de textura durante a estocagem, em temperatura ambiente e sob refrigeração, indicam que a pasta é um novo produto tecnicamente viável, atingindo a estabilidade necessária, apesar de ainda inexistente no mercado. As mudanças na cor do produto final, a partir da cor do broto, durante a estocagem mantiveram as características típicas do broto, mesmo considerando as reações de escurecimento durante o tratamento térmico. Os protocolos desenvolvidos para a produção da pasta, bem como para o pré-processamento e determinação de cianeto podem ser adotados pela agroindústria, sendo enfaticamente indicado o controle devido às variações em glicosídeos cianogênicos da matéria prima e necessária a realização dos testes comprobatórios de eficiência nos pré-processamentos aplicados.

Abstract : Bamboo shoots, widely consumed by Asian peoples, are still relatively unknown and undervalued in Brazil. This work aimed for the development and characterization of a new product, in paste form, from bamboo shoot of Dendrocalamus asper specie. The presence of cyanogenic glycosides in raw material leads to the need of establishment of a pre-processing protocol for shoots, as well as qualitative (quick tests) and quantitative analysis for cyanide, this being one of this work?s specific objective. Further relate to physicochemical, microbiological, texture and color characterization of bamboo shoot paste. Paste?s formula did not compromise bamboo shoots characteristics, as a low fat content food, protein was incorporated and it kept the soluble and insoluble fibers. As to minerals content, sodium, potassium and calcium were relatively kept, except for sodium, although it appears in significantly lower value than most industrialized products. The presence of phenolic compounds in the paste and antioxidant activity, even considering a product of high content of moisture, supports its consumption. As to obtaining of pasta, microbiological results indicate that consumption is safe, right after the paste production and during storage. The texture characteristics during storage, at room temperature and under cold, indicate the technical viability for this product, achieving stability, although it is still nonexistent in the market. Color changes in the final product, comparing to raw material, kept typical characteristics of bamboo shoot during storage, even considering browning reactions due to thermal treatment. Protocols developed to the paste, as well as to pre-processing and cyanide determination, can be adopted by agribusiness, indicating emphatically the control due to cyanogenic glycosides variations in raw material and the need for confirmatory tests of pre-processing efficiency.

APA, Harvard, Vancouver, ISO, and other styles

15

Ainouche, Malika. "Les Populations diploïdes et tétraploïdes du genre Bromus L. , section Bromus Sm. (Poaceae) : analyse de la diversité génétique." Rennes 1, 1993. http://www.theses.fr/1993REN10131.

Full text

Abstract:

La signification de la diversite phenotypique et genetique des populations diploides et tetraploides de la section bromus sm. Est apprehendee aux niveaux morphologique, chromosomique et alloenzymatique. Les 48 populations analysees proviennent d'algerie, du massif armoricain en france, et de collections de jardins botaniques d'origines diverses autour du bassin mediterraneen. Huit especes sont ainsi representees: bromus hordeaceus l. , b. Lanceolatus roth. , b. Intermedius guss. , b. Squarrosus l. , b. Alopecuros poiret, b. Arvensis l. , b. Scoparius l. Et b. Danthoniae trin. Il ressort de cette etude la plus forte variabilite des taxons tetraploides b. Hordeaceus et b. Lanceolatus qui colonisent une grande variete de biotopes, par rapport aux diploides, a repartition tres localisee. Plasticite phenotypique, diversite genetique induite et maintenue par l'allopolyploidie, flux geniques associes a un regime de reproduction flexible et a predominance autogame, se revelent etre la cle des capacites adaptatives et envahissantes des populations de bromes. La differenciation infraspecifique, plus marquee chez b. Lanceolatus, a ete mise en relation avec les conditions bioclimatiques. Chez b. Hordeaceus, la differenciation s'effectue entre populations atlantiques (france) et mediterraneennes (algerie). Au niveau interspecifique, la differenciation genetique est indeniable, quoiqu'inferieure a la moyenne rapportee chez d'autres especes vegetales. Ceci est le reflet de l'origine recente de ces taxons, fortement apparentes, qui forment de veritables complexes posant le probleme de la conception de l'espece chez les vegetaux

APA, Harvard, Vancouver, ISO, and other styles

16

Nuñgulu, Agostinho Tchivange Nandjunge. "Monitorização das espécies de brocas do milho em Angola. Gestão das suas populações com recurso a plantas-isco e plantas repelentes." Doctoral thesis, ISA/UL, 2014. http://hdl.handle.net/10400.5/9260.

Full text

Abstract:

Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia
Stem borers (Insecta: Lepidoptera) in Africa emerge as a major biotic constraints to cereal production. The distribution of species depends on the region and the losses tend to be higher in altitude. For the monitoring of species of stem borers in Angola were used sex pheromone traps for Busseola fusca, Chilo partellus and Sesamia calamistis that were installed in Cavaco, Alto Kapaka, Cela, Chianga and Humpata. To study the management of populations of stem borers using the push-pull system were held in Huambo tests, using as attractive plant Pennisetum purpureum and as repellent plant Desmodium uncinatum. It was found that the three species monitored were present at all sites sampled B. fusca was the dominant species in Chianga, Cela and Alto Kapaka and S. calamistis in Cela and Cavaco. In capturing the pheromone B. fusca ‘Pherobank’ was significantly more effective than pheromone ‘Insect Science’. The incidence of attacks of borers in maize ranged between 86.2% in the control and 14.4% in the treatment maize x P. purpureum x D. uncinatum. For the four years of trials the average production increase in treatment that used attractive and repulsive plants was 340.6%, compared to maize alone

APA, Harvard, Vancouver, ISO, and other styles

17

Baiero, Diogo Sena. "Análise silvicultural de clones de eucalipto em alto fuste e talhadia em sistema silvipastoril." Universidade Federal de Viçosa, 2017. http://www.locus.ufv.br/handle/123456789/20644.

Full text

Abstract:

Submitted by MARCOS LEANDRO TEIXEIRA DE OLIVEIRA (marcosteixeira@ufv.br) on 2018-07-18T13:06:22Z No. of bitstreams: 1 textocompleto.pdf: 591923 bytes, checksum: 51a8a9546f0faa7aa51678ac10d1c76b (MD5)
Made available in DSpace on 2018-07-18T13:06:22Z (GMT). No. of bitstreams: 1 textocompleto.pdf: 591923 bytes, checksum: 51a8a9546f0faa7aa51678ac10d1c76b (MD5) Previous issue date: 2017-07-26
Conselho Nacional de Desenvolvimento Científico e Tecnológico
A integração dos componentes arbóreo, agrícola e animal pode permitir melhor uso da terra, reduzir desmatamento e gerar renda para o produtor. Este estudo visou analisar a viabilidade de implantação e o sortimento em multiprodutos de clones de eucalipto (GG100, 2, 19, 58 e 62), em três arranjos espaciais [(2x2) + 10 m, (3x3) + 9 m e 9x3 m] e dois regimes de corte (alto fuste e talhadia de plantas jovens), em sistemas silvipastoris. O estudo foi realizado na Votorantim Siderurgia S.A., em Vaza te, MG ( 4 ° ’ ° ’ 9’’S e ’’O), no bioma Cerrado, aos 90 meses após o plantio. No componente arbóreo foram analisados sobrevivência, diâmetro quadrático médio, distribuição de diâmetros, produção, sortimento em multiprodutos e índice de área foliar (IAF) e, na pastagem, produção de massa seca. Não foi observada diferença na sobrevivência entre regimes de corte. A sobrevivência foi baixa e o IAF foi elevado, para o clone 2, em especial nos arranjos (2x2) + 10 m e 9x3 m. A variação no IAF foi baixa ao longo da entrelinha. O clone GG100 em talhadia e o clone 58 em alto fuste foram os mais produtivos, ambos no arranjo (3x3) + 9 m. O clone GG100 pode ser manejado através da talhadia em sistemas silvipastoris, pois produziu árvores de diâmetro maior que o alto fuste. Este clone também favoreceu a produção da pastagem na entrelinha de plantio, em especial no arranjo (3x3) + 9 m. O alto fuste apresentou maior aproveitamento volumétrico e receita no sortimento da madeira em multiprodutos que a talhadia, em sistema silvipastoril. A produção de eucalipto na talhadia, considerando horizonte de planejamento de uma única rotação de 90 meses, foi menor do que a produção obtida na idade técnica de corte da talhadia ( ITC ta ) acrescida da produção residual (90- ITC ta ), para a maioria dos tratamentos. Em conclusão, é importante a avaliação do desempenho de genótipos do componente arbóreo, em função de arranjos espaciais e regimes de corte, para obtenção de maior eficiência econômica e técnica de sistemas silvipastoris. A decepa de plantas jovens com manejo em rotações curtas, com base na idade técnica de corte, otimiza a produção da talhadia. O manejo em alto fuste implica em maior receita e rendimento volumétrico que a talhadia com o sortimento em multiprodutos
The integration of tree, crop and livestock components can allow higher land use, reducing deforestation and generating income for producers. The objective of this study was to analyse the feasibility of implantation and the multiproduct assortment of eucalypt clones (GG100, 2, 19, 58 and 62) in three arrangements [(2x2) + 10 m, (3x3) + 9 m and 9x3 m] and two managements regimes (high forest and coppice of juvenile plants) in silvopastoral systems. The study was carried out at Votorantim Siderurgia S.A., in Vazante, MG, Brazil (17°36'09''S and 46°42'02''W), in the savanah biome, at 90 months after planting. Survival, mean square diameter, diameter distribution, production, multiproducts assortment and leaf area index (LAI) were obtained for the tree component, and dry mass production for the pasture. No difference was observed in survival between harvesting regimes. Low survival and high LAI were observed for clone 2, especially in the (2x2) + 10 m and 9x3 m. The variation in LAI was low along the interrow. The GG100 clone coppice and 58 clone high forest were the most productive, both in the (3x3) + 9 m arrangement. The GG100 clone can be managed through coppice in silvopastoral systems, because it produced larger diameter trees than coppice. This clone also favoured pasture production in the interrow, especially in the (3x3) + 9 m arrangement. High forest showed greater production and income with the wood assortment into multiproducts as compared to coppice, in silvopastoral system. The production as coppice, considering a planning horizon of a single rotation of 90 months, was lower than the production as coppice obtained in the technical cutting age ( TCA co ) plus the residual production (90- TCA co ), for most treatments. In conclusion, it is important to evaluate the performance of tree genotypes, as a function of spatial arrangements and harvesting regimes, in order to obtain higher economic and technical efficiency of silvopastoral systems. It is highlighted that coppice of juvenile plants should be analysed based on the technical cutting age, allowing optimization of the coppice production. The high forest management regime allows greater revenue and yield than coppice in multiproduct assortment at 90 months after planting.

APA, Harvard, Vancouver, ISO, and other styles

18

au, A. Mccomb@murdoch edu, and Arthur James McComb. "Plants and the environment." Murdoch University, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070828.135211.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Silva, Filho Jaime Barros da. "Desenvolvimento e otimização de sistema aeropônico para a produção de minitubérculos de batata-semente." Universidade Federal de Viçosa, 2015. http://www.locus.ufv.br/handle/123456789/6906.

Full text

Abstract:

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2015-12-07T10:22:47Z No. of bitstreams: 1 texto completo.pdf: 1433687 bytes, checksum: c7601d98753afba32ef415c327909286 (MD5)
Made available in DSpace on 2015-12-07T10:22:47Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1433687 bytes, checksum: c7601d98753afba32ef415c327909286 (MD5) Previous issue date: 2015-05-20
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Recentemente, sistemas aeropônicos vêm sendo propostos para a produção de batata- semente básica. Existem trabalhos com variada combinação de técnicas na composição destes sistemas. Mas são raros os trabalhos envolvendo a combinação de aeroponia e broto como material propagativo. Da mesma forma, não foi localizado trabalho visando estabelecer a combinação entre tipo de nebulizador, revestimento interno e sentido de nebulização para a produção de batata-semente básica, propagada por broto, em sistema aeropônico. Adicionalmente, ainda não foi realizada a análise de crescimento da planta de batata no sistema aeropônico proposto pelo CIP (Centro Internacional de la Papa). Informações sobre tais dúvidas podem permitir o descortínio de novos sistemas de produção em aeroponia e avanços no sistema existente. Desse modo, os objetivos do presente trabalho foram desenvolver e aperfeiçoar um sistema aeropônico para a produção de minitubérculos de batata-semente básica e caracterizar o crescimento de plantas de batata no sistema aeropônico do CIP, via aspectos morfofisiológicos. Foram conduzidos três experimentos. O primeiro, em 2013, em casa de vegetação não climatizada, em sistema idealizado na Universidade Federal de Viçosa, denominado “Sistema Aeropônico UFV”. Em linhas gerais, esse sistema consiste de balde de polietileno, com orifício na tampa para acomodar as mudas, tubulação de recalque e retorno da solução nutritiva, reservatório, nebulizador, quadro de comando e bomba. Foram utilizadas mudas provindas de brotos de batata-semente, cultivar Ágata, e o experimento foi composto de seis tratamentos, em esquema fatorial 3x2, resultante de três tipos de nebulizadores e dois tipos de revestimento interno do balde, com e sem poliuretano. O desenho para implantação foi em blocos ao acaso com quatro repetições. O segundo experimento, instalado no “Sistema Aeropônico UFV” foi composto de oito tratamentos, em esquema fatorial 4x2, resultantes de quatro tipos de nebulizadores e dois sentidos de nebulização no interior do balde, ascendente e descendente. O desenho foi em blocos ao acaso com quatro repetições. O terceiro experimento foi constituído por nove tratamentos e oito repetições, no delineamento experimental de blocos ao acaso, em sistema aeropônico proposto pelo CIP. Os tratamentos foram épocas de amostragem das plantas realizadas a cada sete dias iniciando-se aos sete dias após o transplantio das mudas. Os dados foram submetidos à análise de variância e de regressão. O “Sistema Aeropônico UFV” é eficaz para produzir minitubérculos e pode ser útil como instrumento experimental devendo ser utilizado o nebulizador Fogger sem antigotas de vazão 14 L/h e com sentido de nebulização descendente. É caracterizado o crescimento de plantas de batata no sistema aeropônico do CIP. Ao longo do ciclo da planta, o comprimento da haste principal aumenta de forma linear; o número de folhas, a área foliar, o índice de área foliar e as massas das matérias secas da raiz, haste, folha e total variam positivamente; a razão de área foliar, a área foliar específica, a taxa assimilatória líquida e a taxa de crescimento relativo decrescem. A razão de massa foliar apresenta o máximo de 0,57 g/g, aos 32,26 dias após o transplantio. A produtividade de minitubérculos, tanto para o número quanto para a massa da matéria fresca, aumenta com comportamentos sigmoidal e potencial, respectivamente. No sistema aeropônico do CIP, a colheita de minitubérculos é iniciada dezoito dias após o transplantio das mudas.
Recently aeroponics systems have been proposed to produce basic potato seed. There are studies with varied combination of techniques to compose these systems. But there are few studies involving the combination of aeroponic and potato sprouts as the nursery material. In the same way, no paper was found seeking to establish combination of nebulizer type, cladding and nebulization direction for the production of basic potato seed, propagated by bud, in aeroponic system. In addition, it has not yet been performed the potato plant growth analysis in the aeroponic system proposed by the International Potato Center (CIP). Information about such doubts may allow the emergence of new aeroponic production systems and advances to the existing one. In this way, the objectives of the present work was to develop and optimize an aeroponic system for the production of basic seed minitubers potato and characterize the potato plants growth in the CIP aeroponic system by morphophysiological aspects. They were conducted three experiments. The first, in 2013, at unheated greenhouse conditioned, in idealized system at the Federal University of Viçosa, called “UFV Aeroponic System”. In general, this system consists of a polyethylene bucket, with hole in the cap to accommodate the seedlings, piping of repression and return of nutrient solution, reservoir, nebulizer, control panel and pump. Seedlings coming from potato seed bud, Agata cultivar, were used and the experiment was composed of six treatments, in a 3x2 factorial, resulting from three types of nebulizers and two types of bucket wall cladding, with and without polyurethane. The experiment was setup in randomized complete block design with four replicates. The second experiment, carried out in the “UFV Aeroponic System”, was composed of eight treatments, in a 4x2 factorial, resulting from four nebulizer types and two nutrient solution nebulization directions inside the bucket, ascending and descending. The experiment was in a randomized complete block design with four replicates. The third experiment accomplished in the aeroponic system proposed by CIP was composed of nine treatments and eight repetitions, in randomized complete block design. The treatments were time of plant sampling collection, every seven days starting at seven days after seedling transplanting. The data were submitted to variance and regression analysis. The “UFV Aeroponic System” is effective to produce minitubers and can be useful as an experimental tool and should be used the Fogger nebulizer without anti-drip flow at 14 L/h with descending nebulization direction. Potato plant growth in the CIP system is morphophysiologically characterized over the cycle. Main stem length increases linearly; leaf number, leaf area, leaf area index and dry matter of root, stem, leaf and total vary positively; leaf area ratio, specific leaf area, net assimilation rate and relative growth rate decrease. The leaf weight ratio presents maximum of 0.57 g/g at 32.26 days after transplanting. Minituber yields, number and fresh weight, increase with sigmoidal and potential behaviors, respectively. At the CIP aeroponic system, minituber harvest begins eighteen days after transplanting.

APA, Harvard, Vancouver, ISO, and other styles

20

Bergez, Espinosa Makarena Paz. "Efecto de dos alternancias de temperaturas en la germinación y emergencia de especies de los géneros Bromus, Vulpia y Erodium." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/152759.

Full text

Abstract:

Memoria para optar al título profesional de Ingeniera Agrónoma
La presente investigación tuvo por objetivo evaluar el efecto de dos alternancias de temperaturas en la germinación y emergencia de tres géneros de interés forrajero, simuladas en dos momentos de inicio del ciclo de crecimiento de la pradera anual de clima mediterráneo. Este estudio se llevó a cabo en el Laboratorio de Manejo de Praderas del Departamento de Producción Animal y el material de estudio fué recolectado en la Estación Experimental Germán Greve Silva ubicada en Rinconada de Maipú, ambos sitios pertenecientes a la Facultad de Ciencias Agronómicas de la Universidad de Chile. Para el ensayo de germinación, se trabajó con semillas de Bromus, Erodium y Vulpia, cosechadas en campo directamente desde las plantas, las cuales una vez en laboratorio, fueron sometidas a prueba de germinación y viabilidad. Los tratamientos fueron el resultado de la combinación de los tres géneros en estudio con las dos alternancias de temperaturas (16ºC/8ºC - temperaturas otoñales, 12ºC/4ºC - temperaturas invernales), obteniendo 6 tratamientos. Las semillas se dispusieron sobre papel filtro en placas petri, en cámara de crecimiento, con humedad constante y un fotoperiodo de 12 horas de luz y 12 horas de oscuridad. Las variables a medir fueron porcentaje de germinación y tasa de germinación por placa petri.

APA, Harvard, Vancouver, ISO, and other styles

21

au, 30075885@student murdoch edu, and Ross F. Brennan. "Zinc Application and its Availability to Plants." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050602.142302.

Full text

Abstract:

Globally, low zinc (Zn) soils are widespread, but one of the largest expanses of such soils is in south west Australia (WA). Early Zn research in the region determined how much fertiliser Zn was required for profitable production of spring wheat (Triticium aestivum L.) and subterranean clover (Trifolium subterraneanum L), the major crop and pasture species at the time. The research showed that Zn sulfate and ZnO were equally effective Zn fertilisers, but ZnO was cheaper and so was widely used. The research indicated that in the year of application, depending on soil type, between 0.5-1.5 kg Zn/ha provided adequate Zn for the production of wheat and subterranean clover. The length of time that a single application of Zn fertiliser remains fully effective in maintaining the production of crops and pasture in future years (residual value; (RV)) had not been determined. This knowledge of the RV of Zn fertilisers is required for soils of WA. The experiments that measured the RV of fertiliser Zn for spring wheat and subterranean clover form the bulk of this thesis. The soils in the region were also initially acutely phosphorus (P) deficient requiring the application of fertiliser P for profitable production. Single superphosphate was the P fertiliser initially used. It was manufactured locally using phosphate rock imported from Nauru and Christmas Islands. This phosphate rock also contained much Zn, and the single superphosphate manufactured from it contained 400-600 mg Zn/kg. At amounts of application needed to provide adequate P, the Zn-contaminated superphosphate also supplied about 90 g Zn/ha. Therefore, early field experiments measured the RV of ZnO applied to soil when single superphosphate was applied annually at >150 kg/ha. In these experiments, the RV of Zn was measured when different amounts of fertiliser nitrogen (N) was applied. This was because it has recently been very profitable to apply fertiliser N to wheat crops, which greatly increased grain yields and so may have increased the demand for Zn, thereby probably decreasing the RV of the original ZnO application. In these experiments, there were many nil-Zn plots. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. No Zn deficiency was detected for up to 23 years after applying ZnO while applying superphosphate at >150 kg/ha per year and for all amounts of N applied. Subsequently cheap imported DAP fertiliser was used for wheat crops instead of locally produced Zn-contaminated single superphosphate and urea. The imported DAP contained about 50 mg Zn/kg (1/12 that of single superphosphate). This new fertiliser strategy induced Zn deficiency in many wheat crops. This led to further field studies to determine the RV of ZnO fertiliser when DAP was applied. The experiments also included 2 Zn-contaminated single superphosphate treatments. In one, no ZnO was applied, and superphosphate was applied at >150 kg/ha per year to match the amount of P applied as DAP to the other treatments. The other treatment was the same, except 1.5 kg/ha Zn as ZnO was applied in the first year only. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. Relative to freshly-applied Zn in each year, the RV of the original ZnO treatments decreased as the length of time that the Zn was in contact with soil increased. However, the rate of decline in the RV was also found to differ with soil type, and was affected by soil pH, clay and organic carbon content of soil, and in alkaline soils with the calcium carbonate content of soil. Parallel glasshouse studies measured the RV of Zn, as Zn sulfate, for wheat and subterranean clover, using many soils from WA and other Australian States. The glasshouse studies also showed that the rate of decline in the RV of the original Zn application varied markedly with soil type and was strongly influenced by soil pH, clay and organic carbon content of soil, and in the alkaline soils, the amount of calcium carbonate in soil. In the above studies, the RV of fertiliser Zn was measured relative to freshly-applied Zn using yield of plants (shoots and grain for wheat, shoots for clover), Zn content in shoots and grain, and soil test Zn using the ammonium oxalate and DTPA procedures. In addition, Zn concentration in young tissue and rest of shoots (glasshouse studies) and young tissue and whole shoots (field studies) was measured, and Zn concentration related to 90 % of the maximum yield (critical Zn in plant parts) was determined. The studies showed that the DTPA soil test procedure, together with soil pH, and clay and organic matter content of soil, was an accurate prognostic test for indicating when Zn deficiency was likely in the next clover or wheat crop. The study confirmed that young tissue (youngest fully expanded leaves) provided critical plant test values for diagnosing Zn deficiency in plants. The plant and soil tests for Zn are now used by commercial soil and tissue testing laboratories. When Zn deficiency was diagnosed early in field grown wheat, Zn sprays can be applied to the crop foliage to prevent or minimise decreases in grain yields at the end of the growing season. Zn sulfate and Zn chelate are the most widely used compounds. This thesis reports the results of a field study to compare the effectiveness of the two compounds when the spray was applied at two growth stages of wheat (Gs14; seedling growth and Gs24; tillering). In addition, Zn applied with the seed while sowing the wheat crop was also included. Zinc applied to the soil while sowing was the most effective treatment. Zn chelate was more effective as a spray than Zn sulfate when applied at the earlier growth stage, but Zn sulfate was cheaper, and both sprays were equally effective when applied at the later growth stage. Recently in the region, durum wheat (T. durum L.), narrow-leafed lupin (Lupinus angustifolius L.), yellow lupin (L. luteus L.), white lupin (L. albus L.), canola (Brassica napus L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.) and lentil (Lens culinaris Medik) were all increasingly grown in rotation with spring wheat. Consequently, the Zn requirement of the new crops was compared with the Zn requirements of spring wheat. Species requiring less Zn than spring wheat to produce the same relative yield were faba bean, chickpea, albus lupin and canola; species requiring more Zn were lentil and durum wheat. Spreadsheet models were developed to determine when re-application of fertiliser Zn was required for low and high production systems. Relative to freshly-applied Zn, the rate of decline in the RV of Zn applied in a previous year varied depending on the amount of Zn applied, time the Zn was in contact with soil since application, properties of the soil (soil pH, % clay, % organic carbon, % free calcium carbonate), plant species, and the amount of Zn removed in harvested grain or hay. The thesis has culminated in a better understanding of Zn in the agricultural production systems of WA. The distribution and correction of Zn deficiency is now predictable for the many soil types and cropping systems of WA. Accurate identification of Zn deficiency for a range of crop and pasture species by plant analyses, typically the youngest mature leaf, is now possible for local conditions. With the calibration of the DTPA Zn soil test for soils of WA, particularly for wheat the major crop species grown in WA, prognosis of potential Zn deficiency can now be predicted before the appearance of Zn deficiency or loss in plant production.

APA, Harvard, Vancouver, ISO, and other styles

22

com, m. nikraz@gmail, and Magid Nikraz. "Integration of Operational Tasks in Chemical Plants." Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070417.150114.

Full text

Abstract:

The overall, coordinated management of different operational tasks in a chemical plant can improve operational efficiency. These operational tasks can be hierarchically categorised, from the lowest to highest level, as: data acquisition; regulatory control; monitoring; data reconciliation; fault detection and diagnosis; supervisory control; scheduling; and planning. Although each of these tasks is responsible for a particular function, they are dependent on each other, which is why an approach wherein all the different tasks can be integrated into a single unified framework is desirable. While integration has important benefits such as a significant reduction in operator workload and improved decision making, its realisation presents considerable challenges. Few previous works have addressed this topic and even fewer have investigated recent computing paradigms which may greatly assist in the development of a unifying framework. Multi-agent systems were introduced and investigated in this study as a possible means for achieving integration of operational tasks in chemical plants. Multi-agent systems are the subject of a sub-field of computing research known as agent-based computing. Agent-based computing represents a relatively recent and powerful high-level computing paradigm. Initially, a number of software applications were developed for the purposes of this study to assist realisation of the operational tasks. To simplify the process of system development and provide guidance for those unfamiliar with multi-agent systems wishing to adopt the proposed technique, an extensive methodology was devised. The operational tasks were then integrated using the proposed methodology to form an integrated multi-agent system, with the pilot plant at Murdoch University being used as a test base for the solution. The results were positive and demonstrated that the proposed agent-based solution was able to effectively account for the pilot plant setting. It was concluded that, in addition to presently available integration techniques and base technologies, the agent-based approach to integration of operational tasks in chemical plants presents a viable alternative solution.

APA, Harvard, Vancouver, ISO, and other styles

23

Fortuné, Philippe. "Phylogénie et dynamique des gènes dupliqués chez les plantes polyploïdes : évolution dans les genres Bromus L. et Spartina Schreb. (Poaceae)." Rennes 1, 2007. http://www.theses.fr/2007REN1S029.

Full text

Abstract:

Les duplications de génomes ont joué un rôle important dans la spéciation et l’adaptation chez les plantes. Ce travail vise à élucider l’histoire évolutive de lignées polyploïdes présentant un intérêt écologique particulier en raison de leur expansion rapide dans les genres Bromus et Spartina (Poaceae). Différentes analyses phylogénétiques combinant les informations des génomes chloroplastique et nucléaire ont permis d’élucider l’origine des espèces polyploïdes et de montrer la prépondérance de l’évolution réticulée (allopolyploïdie) dans les groupes étudiés où l’origine hybride semble avoir joué un rôle important dans le succès écologique de ces espèces. L’étude plus particulière du gène Waxy a montré une rétention variable des copies homéologues selon les lignées. Les taux d’évolution de ces copies dupliquées restent sous contrainte sélective
Genome duplication is an important speciation process in plants promoting diversification and adaptation. This work aims at unravelling the evolutionary history of polyploid lineages in genus Bromus and Spartina (Poaceae) that display polyploid species of ecological interest, due to their rapid expansion. Various phylogenetic analyses based on sequences from the chloroplast and the nuclear genomes have helped to elucidate the origin of the polyploidy. Reticulate evolution through allopolyploidy appears to be the rule in these groups, having an important impact on the ecological success of these species. Variable retention rates of homeologues were encountered for the nuclear Waxy gene depending on the lineages. The nuclear Waxy gene presented a variable retention rate of the homeologous copies depending on the lineages. No relaxation of selective constraints was detected on the retained gene copies

APA, Harvard, Vancouver, ISO, and other styles

24

Dalagnol, Gilberto Luiz. "Diversidade genética de 11 acessos e progênies e performance agronômica de dois sintéticos de Bromus auleticus Trinius." Florianópolis, SC, 2000. http://repositorio.ufsc.br/xmlui/handle/123456789/78545.

Full text

Abstract:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias.
Made available in DSpace on 2012-10-17T15:46:46Z (GMT). No. of bitstreams: 0
O Bromus auleticus é uma forrageira perene, nativa dos campos naturais do Sul do Brasil, com alto potencial de produção. Foram caracterizados geneticamente 11 acessos e quatro progênies e a partir de quatro destes acessos obteve-se dois sintéticos: SLI, sem controle da polinização e SLII, do intercruzamento entre estes quatro acessos. Avaliou-se a performance agronômica e características morfológicas e bromatológicas dos sintéticos. Os resultados revelaram superioridade do SLII para matéria seca, altura da planta, altura e diâmetro do pseudocaule e afilhamento. As análises bromatológicas apresentaram valores comparáveis a outras espécies forrageiras cultivadas na região. Para estimar a diversidade genética e a taxa de cruzamento utilizou-se a eletroforese de isoenzimas e marcadores RAPD. Entre os acessos o número médio de alelos por loco foi de 2,0, com 73,3% de locos polimórficos. A heterozigosidade observada e esperada foram 0,345 e 0,340, respectivamente. O uso de sete iniciadores resultando na amplificação de 42 bandas, das quais, 64,3 % representaram regiões polimórficas (RAPD). A taxa de cruzamento nas progênies foi de 1,069, confirmando a natureza alógama da espécie. A alta variabilidade genética exibida pelos acessos e sua caracterização facilitarão a escolha de parentais para programas de melhoramento, que permitirá o cultivo em áreas de ocorrência natural e ou degradadas.

APA, Harvard, Vancouver, ISO, and other styles

25

Estelrich, Hector Daniel. "Allocation du carbone chez une Graminée annuelle (Bromus madritensis L. ) et une Graminée pérenne (Bromus erectus Hud. ) cultivées sur deux sols de fertilité différente : importance de l'"effet rhizosphère"." Montpellier 2, 1990. http://www.theses.fr/1990MON20262.

Full text

Abstract:

Dans le but de determiner l'importance de l'effet rhizosphere sur les modalites de fonctionnement des vegetaux, des plantes annuelles et perennes du benre bromus croissant dans deux sols de fertilite differente, ont ete exposees a une atmosphere enrichie en #1#4co#2 a differents stades de leur cycle de vie. Le contenu en #1#4c de la respiration souterraine, des compartiments aeriens, des racines et du sol a ete mesure apres chaque marquage ainsi que le contenu en carbone et en azote de la biomasse aerienne et souterraine. Il a ete detecte un fort effet de la fertilite du sol sur la croissance des plantes ainsi qu'un patron different de croissance et de developpement du systeme racinaire. Ces resultats indiquent que les plantes semblent etre capables de moduler leur croissance en fonction de la richesse de l'habitat, ce qui se manifeste egalement dans l'effort reproducteur qui depend directement du statut en nutriments dans le sol. L'analyse des modalites de repartition du carbone dans le systeme plante-sol et surtout au niveau de la rhizosphere a permis de mettre en evidence des differences importantes concernant le cycle de vie et le type de sol. L'integration des resultats obtenus dans cette etude permet de donner un sens qualitatif a l'effet rhizosphere en terme d'efficacite du carbone investi, et laisse apparaitre deux types de comportements tres differents etroitement lies au cycle de vie. Chez l'espece annuelle, l'effet rhizosphere est tres couteux en energie, il varie avec la fertilite du milieu et s'avere moins efficace si l'on juge par la quantite d'azote extraite par les plantes. Il servirait a satisfaire leurs besoins nutritionnels en peu de temps. Chez l'espece perenne, cet effet est moins couteux en energie et beaucoup plus efficace vis-a-vis de la quantite d'azote extraite. Il permettrait aux plantes une exploitation plus efficace du milieu edaphique

APA, Harvard, Vancouver, ISO, and other styles

26

Dal, Vesco Lirio Luiz. "Culturas nodulares e micropropagação de bromélias nativas da Mata Atlântica (Billbergia zebrina e Vriesea reitzii): bases para a conservação e propagação massal." reponame:Repositório Institucional da UFSC, 2010. http://repositorio.ufsc.br/xmlui/handle/123456789/94293.

Full text

Abstract:

Tese (Doutorado) - Universidade Federal de Santa Catarina, Centro de Ciencias Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2010
Made available in DSpace on 2012-10-25T08:23:54Z (GMT). No. of bitstreams: 1 279462.pdf: 1524764 bytes, checksum: 6aeeb1f55ba566debda7335ec88f37c1 (MD5)
As bromélias representam um grupo taxonômico importante sob os prismas ecológico e econômico, ocorrendo majoritariamente no bioma Mata Atlântica, o qual se encontra entre os mais ameaçados do planeta. Assim, o desenvolvimento das tecnologias que utilizam sistemas regenerativos de alta eficiência de cultivo ou de conservação de germoplasma vegetal apresenta alto potencial de aplicação. No presente trabalho o sistema de micropropagação baseado na indução e desenvolvimento de culturas nodulares (CNs) foi estudado e caracterizado a partir de segmentos nodais extraídos de brotos estiolados em Billbergia zebrina, e a partir de sementes e de bases foliares em Vriesea reitzi. Foi também testada a suplementação ao meio de cultura MSB de diferentes tipos, concentrações, balanços de fitorreguladores e submetidos a diferentes condições de cultivo, durante a indução, regeneração e alongamento de microbrotos. Em B. zebrina, segmentos nodais, extraídos de brotos estiolados foram cultivados em meios de cultura MS liquido, suplementados com diferentes concentrações de TDZ, ANA e BAP. CNs e folhas de brotações foram empregadas para análises moleculares por meio de marcadores AFLP. O uso do meio de cultura MS com diferentes concentrações de TDZ resultou em CNs com diferentes morfologias e potenciais regenerativos. CNs induzidas com TDZ (0,01 µM) e subcultivadas em meio de cultura MSB isento de fitorreguladores apresentam alta freqüência regenerativa. CNs originadas em meio com TDZ, (0,1 µM) quando foram subcultivadas em MSB com ANA (2 µM) e 2-iP (4 µM) resultaram em maior número médio de brotos adventícios por grama de CN inoculada. Brotos alongados (>3 cm) foram aclimatizados com sucesso em ambiente in vivo e mudas transplantadas para vasos apresentaram padrão normal da espécie. Análises histológicas e em MEV revelaram que a indução de CNs ocorreu a partir da região da gema do segmento nodal e confirmaram características morfogenéticas intermediárias entre organogênese e embriogênese somática, típico de CNs. A análise molecular com base na técnica de AFLP revelou 88% de similaridade dos regenerantes em relação à planta mãe, sugerindo a ocorrência de alta diversidade. Esta diversidade pode ter aplicação em programas de melhoramento genético ou como ferramenta eficaz em programas de conservação desta espécie. Em V. reitzii foram estudados os fatores determinantes do controle da morfogênese in vitro das CNs. Os fitorreguladores suplementados ao meio MSB inibiram a germinação das sementes e promoveram a indução de CNs após duas semanas em cultivo. CNs induzidas em meio suplementado com ANA (4 µM) e subcultivadas em meio MSB com ANA e 2-iP (2 µM cada) apresentaram textura granular e alta taxa de proliferação. O cultivo destas CNs em meio MSB suplementado com AIA (4 ?M) resultou em alto número médio de microbrotos (1.468 brotos/g de CNs). A partir do modelo de regressão foi possível inferir que o número máximo de brotos alongados (66,3 brotos/g) pode ser obtido com o subcultivo dos microbrotos em meio MSB suplementado com AIA (2 µM) e AG3 (10 ?M). Em explantes foliares, em todos os meios de cultura testados observou-se a indução de CNs a partir da região basal. Estas CNs responderam de forma diferencial aos tratamentos em termos de características morfogenéticas e potencial regenerativo. CNs mantidas na presença de luz resultaram em maior produção de massa fresca e de microbrotos em comparação com aquelas mantidas na ausência de luz. CNs subcultivadas em meio MSB líquido e suplementado com ANA (4 µM) e 2-iP (2 µM) revelaram elevada eficiência regenerativa. A maior eficiência regenerativa e proliferação de microbrotos foram obtidas com o uso do meio MSB suplementado com ANA e 2-iP (2 µM cada). O subcultivo em meio MSB suplementado com AG3 (10 µM) promoveu um maior alongamento de brotos e de forma sincronizada. A utilização destes meios de cultura resultou em uma eficiência regenerativa de 12,4 g/g de CN inoculada. Estima-se, a partir disto, uma regeneração de mais de 5.300 novos microbrotos e na fase de alongamento, uma taxa efetiva de 75% destes microbrotos podem ser convertidos em brotos completos a cada 10 semanas de cultivo. As análises estruturais das CNs revelaram que os processos de indução da morfogênese e da regeneração de microbrotos ocorrem a partir da proliferação de grupos de células meristemáticas e que desenvolvem a formação de múltiplos meristemas caulinares. Estas estruturas regenerativas sustentam a classificação de CNs organogênicas. Brotos maiores do que 3,0 cm resultaram em mais de 95% de sobrevivência ex vitro. Os resultados obtidos com as CNs de V. reizii se configuram, com base em estudos morfohistológicos, em uma rota regenerativa in vitro intermediária entre a organogênese e a embriogênese somática. Esta rota apresenta elevado potencial regenerativo para a propagação em larga escala de bromélias ornamentais e/ou ameaçadas de extinção, como são o caso de V. reitzii e B. zebrina.

APA, Harvard, Vancouver, ISO, and other styles

27

Yager, Lisa Y. "Watching the grass grow effects of habitat type, patch size, and land use on cogongrass (Imperata cylindrica (L.) Beauv.) spread on Camp Shelby Training Site, Mississippi /." Diss., Mississippi State : Mississippi State University, 2007. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Menezes, Anna Christina Passos [UNESP]. "Reguladores vegetais na brotação, características dos cachos e produtividade da videira cv. Itália no Vale do São Francisco, BA." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/103238.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:32:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-05Bitstream added on 2014-06-13T19:43:10Z : No. of bitstreams: 1 menezes_acp_dr_botfca.pdf: 701350 bytes, checksum: 6123fc27fa833d40b071d8d498164c0c (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O presente trabalho foi conduzido na Fazenda Cooperyama – Juazeiro- BA, com o objetivo de estudar a eficiência de reguladores vegetais na brotação e características dos cachos da uva ‘Itália’. Para avaliação da brotação das gemas foram efetuadas observações em dias alternados determinando-se o número de brotos. Os tratamentos considerados foram: T1: Testemunha; T2: 2,45 g L-1 de cianamida hidrogenada; T3: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico; T4: 0,09 mg L-1 de cinetina, 0,05 mg L-1 de ácido giberélico e 0,05 mg L-1 de ácido indolilbutírico; T5: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico + 10 kg de nitrogênio e 9 kg de Ca ha-1; T6: 0,09 mg L-1 de cinetina, 0,05mg L-1 de ácido giberélico e 0,05 mg L-1 de ácido indolilbutírico + 10 kg de nitrogênio e 9 kg de cálcio ha-1; T7: 0,1 mg L-1 de cinetina + 10 kg de nitrogênio e 9 kg de cálcio ha-1; T8: 0,2 mg L-1 de cinetina + 10 kg de nitrogênio e 9 kg de cálcio ha-1 e T9: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico + 2,45 g L-1 de cianamida hidrogenada + 10 kg de nitrogênio e 9 kg de cálcio ha-1. Para caracterização dos cachos foram avaliados a massa, comprimento e largura média dos cachos; massa, comprimento e diâmetro médio das bagas; massa seca dos engaços; número médio de bagas/cacho; número médio de cachos/planta; produtividade média/planta; sólidos solúveis, acidez titulável e ratio. Os tratamentos considerados foram 2,5; 20 e 20 mg L-1 de ácido giberélico em pó; 0,019; 0,25; 0,038; 0,5; 0,076; 1,0 mL L-1 de ácido giberélico líquido; 0,01; 0,05, 0,075; 0,1, 0,5% de cinetina, ácido giberélico e ácido indolilbutírico, respectivamente e 1,5; 3,0; 6,0; 20,0; 40,0; 80,0 mL L-1 de...
The trial was carried out in the farm Cooperyama – Juazeiro-BA, with the objective to study the efficiency of plant growth regulators on sprouting and on the cluster characteristics of ‘Itália’ grapes. To evaluate the bud sprouting, observations were done on alternate days and the number of sprouts were registered. The treatments considered were: T1: Control; T2: 2,45 g L-1of the hydrogen cyanamide ; T3: 0,045 mg L-1of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1of indolilbutiric acid; T4: 0,09 mg L-1 of kinetin, 0,05 mg L-1 of gibberellic acid the 0,05 mg L-1 of indolilbutiric acid; T5: 0,045 mg L-1 of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolilbutiric acid 0,045 mg L-1 of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolilbutiric acid + 10 kg the nitrogen e 9 kg the calcium ha-1; T6: 0,09 mg L-1 of kinetin, 0,05 mg L-1 of gibberellic acid the 0,05 mg L-1 of indolilbutiric acid + 10 kg the nitrogen e 9 kg the calcium ha-1; T7: 0,1 mg L-1 of kinetin + 10 kg the nitrogen e 9 kg the calcium ha-1; T8: 0,2 mg L-1 of kinetin + 10 kg the nitrogen e 9 kg the calcium ha-1 e T9: 0,045 mg L-1of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolbutiric acid + 2,45 g L-1of the hydrogen cyanamide + 10 kg the nitrogen e 9 kg the calcium ha-1. For cluster characterization, weight, length and average width of clusters; weight, length and average diameter of berries; dry weight of rachis; average number of berries/cluster; average number of clusters/plant; average productivity/plant; soluble solids content; acidity and ratio were evaluated. The treatments considered were 2.5; 20 and 20 mg L -1 of gibberellic acid; 0.019; 0.25; 0.038; 0.5; 0.076; 1.0 mL L-1 of gibberellic acid liquid of 0.01; 0.05, 0.075; 0.1, 0.5 % of kinetin, gibberellic acid the indolilbutiric acid, respectivemant and 1.5; 3.0; 6.0; 20.0; ...(Complete abstract click electronic access below)

APA, Harvard, Vancouver, ISO, and other styles

29

Jensen, Alexa Lunt. "Evaluating Nitrogen and Carbon Differences in Standing Litter from Normal and Prematurely Senesced Bromus tectorum Plants." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8265.

Full text

Abstract:

Bromus tectorum, an invasive winter annual, has displaced native vegetation throughout the western United States. Bromus tectorum litter influences nutrient cycling near the soil surface as well as plant establishment. Failed seed production of B. tectorum occasionally occurs in the field, with plants exhibiting weak flowering culms that turn straw-colored in spring when normal plants are green or purple in color. Because annual grasses transport most soluble carbon (C) and nitrogen (N) to reproductive organs, seed production failure results in significantly different fates for these nutrients compared with normal plants. As part of larger efforts to understand events leading to large-scale seedling emergence failure (termed die-offs), occasionally observed in near mono-cultures of B. tectorum, we here test the hypothesis that prematurely senesced litter associated with seed production failure has higher soluble C and N than normal litter. C and N concentrations of aboveground biomass were compared for normal and prematurely senesced B. tectorum plants. Two methods were used to cause premature senescence: fungal pathogen infection with Clarireedia capillus-albis and glyphosate herbicide application. In a related experiment, field sampling of normal and prematurely senesced plants under natural conditions was conducted to compare C and N levels in-situ. Herbicide-induced senescence resulted in 1.5 to 2 times greater soluble C concentrations, but fungal infection had no effect on soluble C under experiment conditions. Prematurely senesced litter had increased total N concentrations, resulting in lower C:N ratios. The C:N ratio for prematurely senesced plants (averaged across all studies) was 68:1, whereas mature normal plants averaged 243:1. These findings illustrate failed seed production associated with premature senescence results in B. tectorum litter with significantly higher N concentrations and can result in increased soluble C concentrations. Altered nutrient status may contribute to changes in soil microbial activity, including activity of soilborne pathogens found in die-offs.

APA, Harvard, Vancouver, ISO, and other styles

30

Briceño, Pinto Matías. "Evaluación de la aplicación de tidiazurón sobre el área foliar del brote y tamaño de baya en uva de mesa var. Flame seedless." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/147756.

Full text

Abstract:

Tesis presentada como parte de los requisitos para optar al Título Profesional de Ingeniero Agrónomo y al Grado de Magíster en Ciencias Agropecuarias, Mención Producción Frutícola
Este trabajo tuvo como objetivo evaluar el efecto de tidiazurón (TDZ) sobre el desarrollo del área foliar de brotes de vides ‘Flame Seedless’, ubicadas en un huerto comercial en la localidad de El Tránsito, Provincia del Huasco, Región de Atacama, Chile. Se realizaron aplicaciones de TDZ en precuaje, en distintos largos de brote (15, 30 y 45 cm), utilizando el producto comercial Splendor® (5% p/v SC, Bayer CropScience). En el ensayo se establecieron 4 tratamientos, aplicados en plantas con igual nivel de producción, 20 racimos por planta. Todas las aplicaciones tuvieron una concentración de 1,5 mg·L-1 de TDZ. El tratamiento control (T0), correspondió a plantas sin aplicación de TDZ; T1 a plantas con 3 aplicaciones de TDZ (15, 30 y 45 cm de largo de brote) y con dosis de producto de 126 mL· ha-1 ; T2 a plantas con aplicación de TDZ en 2 oportunidades (15 y 30 cm de largo de brote) y con dosis de producto de 84 mL· ha-1 ; y T3 a plantas con aplicación de TDZ en largo de brote de 15 cm y con dosis de producto de 42 mL· ha-1 . En las aplicaciones se utilizó un mojamiento de 1400 L·ha-1 , utilizando barra pulverizadora. La aplicación de TDZ, en 3 momentos de largo de brote (T1), fue capaz de incrementar el área foliar del brote (2.774 cm2 ) al compararla con vides sin aplicación (1.919 cm2 ). El análisis de componentes principales mostró una fuerte asociación entre T1 y el número de hojas totales en el brote, el número y largo de entrenudos y el número de feminelas en brote. Todas las aplicaciones de TDZ disminuyeron el porcentaje de racimos en la categoría de calibre comercial más baja (S), de un 70 a un 20%. Pero no lograron incrementar el porcentaje de racimos en las categorías más altas. T1 produjo un raquis con mayor peso, mayor grosor en el eje y hombros, y menor flexibilidad.
The objective of this study was to evaluate the effect of thidiazuron (TDZ) on leaf area development of shoots of 'Flame Seedless' vines, located in a commercial vineyard in El Transito, Huasco Province, Atacama Region, Chile. TDZ was applied at pre fruit set, at various shoot lengths (15, 30 and 45 cm), using the commercial product Splendor ® ( 5% w/v CS, Bayer CropScience ). Four treatments were established, applied to plants with the same production level, 20 clusters per plant. All applications had a concentration of 1.5 mg·L-1 TDZ. Control treatment (T0) corresponded to plants without the application of TDZ; T1, plants with three applications of TDZ (15, 30 and 45 cm of shoot length) and product dose of 126 mL· ha-1 ; T2, plants with TDZ application at two occasions (15 and 30 cm of shoot length) and product dose of 84 mL· ha-1 , and T3, plants with TDZ application at shoot length of 15 cm and product dose of 42 mL· ha-1 . Spray volume used for applications was 1400 L·ha- 1 , with an airblast sprayer. TDZ application at three times of shoot length (T1) increased total leaf area of shoot (2774 cm2 ) compared to vines with no application (1919 cm2 ). The principal component analysis showed a strong association between T1 and total shoot leaf number, the number and length of internodes and number of lateral shoots. All TDZ applications decreased the percentage of clusters in the lower commercial size category (S), 70 to 20%. But TDZ treatments failed to increase the percentage of clusters in the higher categories. T1 produced rachis with greater weight and thickness, greater shoulders thickness and decreased flexibility

APA, Harvard, Vancouver, ISO, and other styles

31

Herman, Brook Danielle. "Testing the Floristic Quality Assessment Index in natural and created wetlands in Mississippi, USA." Master's thesis, Mississippi State : Mississippi State University, 2005. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Lobo, Patricia Carneiro. "Tolerancia a inundação de plantas de Talauma ovata St-HIL- e aspectos do seu comportamento em uma mata ciliar da baciado Rio Jacare Pepira, Brotas, SP." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314906.

Full text

Abstract:

Orientador : Carlos Alfredo Joly
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-07-18T09:20:25Z (GMT). No. of bitstreams: 1 Lobo_PatriciaCarneiro_M.pdf: 4317605 bytes, checksum: c75acc7526ca7e91f75f9401106133f4 (MD5) Previous issue date: 1993
Resumo: O estudo de uma população de Talauma ovata, em uma mata de brejo no município de Brotas revelou que ela apresenta um padrão de distribuição contagioso, restrito aos locais de solo hidricamente saturado. Trata-se de uma população com predomínio de indivíduos jovens, e uma distribuição de classes de tamanho gradualmente decrescente, indicando ser capaz de regenerar-se a partir de sementes. A capacidade de a espécie ocorrer em locais encharcados deve-se principalmente à tolerância das plântulas à anaerobiose do sistema radicular, uma vez que as sementes são incapazes de germinarem em solo alagado. As sementes são dispersas na época mais seca e germinam dando origem a plântulas que toleram estresse por excesso de água, típico da estação chuvosa. Várias respostas estão envolvidas no mecanismo de tolerar tanto a falta de oxigênio no solo, quanto de às conseqüências desta para o metabolismo do sistema radicular. Alterações morfológicas, como hipertrofia de lenticelas e da base do caule, formação de raízes adventícias e de novas raízes durante o alagamento, ocorrem. Estas raízes novas são maior anatomicamente diferentes das originais, pois apresentam porosidade. As alterações morfo-anatômicas possibilitam a difusão do 02 da parte aérea para o sistema radicular. O difundido até as raízes pode proporcionar uma maior oxigênio produção energética pela respiração aeróbica, fornecendo energia para outros processos que mantêm a viabilidade da planta. Alterações metabólicas também contribuem para a sobrevivência ao estresse. A atividade da ADH é acelerada, proporcionando maior produção de ATP, e o seu produto, o etanol, parece ser eliminado antes de atingir níveis tóxicos. O aparato respiratório não é comprometido, o que possibilita a retomada das atividades quando a condição aeróbica é restaurada. Assim, a espécie Talauma ovata apresenta adaptações que um estresse pronunciado, assim como adaptações que evitam permitem à planta sobreviver à saturação hídrica do solo
Abstract: The population of Talauma ovata (Magnoliaceae) studied in a swamp gallery forest area in the municipality of Brotas, State of São Paulo (48º 08' W; 22º 08' S), presented a contagious distribution pattern, with individuals densily concentrated in shallower and waterlogged areas. The demographic study carried out showed that the age structure of the population follows the inverted J pattern, showing the importance of seed germination and seedling establishment for the maintenance of the population. Seedlings and adults aggregation in low lying areas, where the water table is at, or above, soi1 surface a large part of the year, is due to the flooding tolerance of seedlings, because the seeds do not germinate in waterlogged soils. Seed dispersion and germination take place in the drier periods of the year, when the water table is just be10w soil surface. Waterlogging induces morpho-anatomic responses, such as the hipertroph of. lenticels and of the base of the trunk, associated with the development of new tap roots as well as adventitious roots with a higher percentage of aerenchyma. These responses resulted in a measured increase in oxygen diffusion from the aerial part to the root system. Aeration of the root system may keep its metabolism partially aerobic, with a higher energetic production than a fully anaerobic metabolism. Metabolic responses include an enhance of the fermentative pathway, with an increase in ADH activity and of the level of ethanol in the root system. Nevertheless, ethanol diffusion to the surrounding environment keeps the internal level below toxic concentrations. The respiratory apparatus is well preserved and therefore able to resume aerobic respiration as soon as the stress is over. The compromise between metabolic and morpho-anatomic changes is vital to keep the viability of the seedlings in water10gged sites, and the success of Talauma ovata in swampy areas of gallery forest. T. ovata is always among the ten most important trees in the phytossociological surveys carried out in these kind of environment in SE Brazil
Mestrado
Mestre em Biologia Vegetal

APA, Harvard, Vancouver, ISO, and other styles

33

Fracaro, Antonio Augusto. "Aplicação de ethephon em videira 'Niagara Rosada' (Vitis labrusca L.) visando produção na entressafra do Estado de São Paulo /." Jaboticabal : [s.n.], 2004. http://hdl.handle.net/11449/105186.

Full text

Abstract:

Orientador: Fernando Mendes Pereira
Banca: João Alexio Scarpare Filho
Banca: Sérgio Ruffo Roberto
Banca: Antonio Baldo Geraldo Martins
Banca: Aparecida Conceição Boliani
Resumo: Para a produção de uva na entressafra (setembro-outubro), é necessário que a poda seja realizada em período de provável ocorrência de baixas temperaturas, o que prejudica a emissão e desenvolvimento de brotos. Embasado em trabalho anterior, objetivou-se desenvolver uma técnica para viabilizar a emissão e desenvolvimento das brotações do cv. Niagara Rosada, mesmo em condições desfavoráveis com temperaturas abaixo de 10 ºC. Os experimentos foram conduzidos em vinhedos comerciais, na região de Jales-SP. Foram testadas quatro concentrações de ethephon (0; 720; 1.440 e 2.160 mg.L-1), aplicado de maio a junho, via foliar antes da poda de produção, em seis distintos experimentos, sendo três em 2001 e três em 2002. Verificou-se que a aplicação de ethephon promoveu o desfolhamento das videiras, principalmente nas concentrações de 1.440 e 2.160 mg.L-1. A aplicação em plantas pouco enfolhadas e/ou em período sem ocorrência de baixas temperaturas,não produziu resultados estatisticamente significativos na produção. Porém, observou-se um aumento na emissão e no desenvolvimento dos brotos nas concentrações mais elevadas. A aplicação de ethephon na concentração de 2.160 mg.L-1 em videiras com enfolhamento superior a 70% e temperaturas abaixo de 10 ºC, propiciou resultados excelentes no que se refere ao maior número de gemas brotadas, ao maior desenvolvimento dos ramos (comprimento e diâmetro) e a maior produção. O uso de ethephon não alterou o período da poda à floração, os teores de sólidos solúveis totais e a acidez total titulável mas, proporcionou aumento no comprimento e peso dos cachos e das bagas, na largura dos cachos e no diâmetro das bagas, melhorando a qualidade da uva.
Abstract: For off-season grape production (September-October), pruning it is necessary in period of probable occurrence of low temperatures, what damages the emission and development of sprouts. Based in previous work, it was developed a technique to make possible the emission and development the sprout of the grape 'Niagara Rosada', even though unfavorable conditions of climate. These studies were carried out at commercial vineyards, in region of Jales, SP, Brazil. Four levels of ethephon (0; 720; 1,440 and 2,160 mg.L-1), applied from May to June, on leaves before the frutification pruning, in six experiments, on 2001 and three on 2002. It was observed that application of ethephon promoted defoliation of the grapevines, mainly in levels of 1,440 and 2,160 mg.L-1. The application in plants with less leaves and/or period without occurrence of low temperatures, did not produce significant results in the production. However, a trend of increase in emission and development of sprouts when higher levels of ethephon was observed. The application of ethephon (2,160 mg.L-1) on grapevines with more that 70% of leaves, in period of occurrence of lower temperatures (smaller 10 ºC), propitiated excellent results regarding the number of sprouted buds, shoot growth (length and diameter) and production. The use of ethephon did not modify the duration of the period from pruning to flowering, the total soluble solids and titrabre concentration acidity, but increased the length, diameter, the width and mass of the clusters and berries, improving the grape quality.
Doutor

APA, Harvard, Vancouver, ISO, and other styles

34

au, chrisn@npmicro com, and Christopher Jack Newell. "In vitro soil-less (IVS) rooting medium." Murdoch University, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070514.132029.

Full text

Abstract:

The principle hypothesis of this thesis is that hypoxia, in agar-based media, compromises rooting in vitro. From a practical point of view this is important because most plant tissue culture activities require the material to be successfully acclimatised in a nursery environment. Compromised rooting often results in excessive losses at this stage which are costly and inconvenient. In addition, many plants with commercial and/or scientific interest remain unavailable as they are not able to be rooted and acclimatised reliably. The use of agar as a rooting medium has limited the capacity of plant tissue culture to clonally propagate many plants. The thesis begins by demonstrating how poorly some plants respond to agar rooting media. Juvenile Chamelaucium hybrid microcuttings were pulsed with IBA 40 ìM and then placed for 3 weeks on either M1 (½ MS) or aerated in vitro soil-less substrate (IVS) (Chapter 2). IVS had 4282% rooting at the end of Stage 3 compared with 01% in agar. Shoot survival for IVS-rooted microcuttings was significantly greater than M1-rooted shoots. Pulsed shoots placed in IVS showed root primordia after 7 days. In contrast, shoots placed in agar showed no root primordia after 21 days and formed callus but did not root when subsequently placed in IVS for a further 4 weeks. The agar medium almost totally and permanently inhibited the capacity of competent shoots to form root primordia and roots. The effectiveness of different types of aerated and non-aerated media, including IVS, were tested to validate the hypothesis (Chapter 3). Microcuttings from shoot cultures of two Australian plants Grevillea thelemanniana and Verticordia plumosa x Chamelaucium uncinatum were pulsed for 7 days on a high auxin (40 ìM IBA), agar-solidified medium in the dark. Rooting of the microcuttings was then compared on five experimental substrates: a) standard agar M1 medium (½ MS, no hormones, 8 g agar L-1), b) porous-agar medium (½ MS, no hormones, 30 g agar L-1, solidified then blended to provide aeration), c) white sand wet with liquid M1, d) white sand with M1 medium containing agar, and e) IVS. A separate experiment involved flushing the IVS soil profile with low or normal oxygen. Low and variable rooting percentages were recorded on the controls on M1 medium. Root induction and average total root length per microcutting at final harvest were significantly higher using the porous media including IVS, blended agar or white sand. The M1 medium and the addition of M1 medium to sand suppressed the percentage rooting and elongation. Flushing the IVS rooting medium with low oxygen also suppressed rooting. The experiments showed that increasing the air-filled porosity of the rooting medium has a positive effect on rooting and this is most likely due to the increased oxygen at the base of the microcutting. The role of ethylene, and the sugar and nutrients in M1 were not investigated. The efficacy of the IVS protocol on a range of Australian herbaceous and woody species was investigated to determine whether the observed benefits were generic or plant specific (Chapter 4). Improved rooting in IVS compared to agar was shown for 28 Australian species and genotypes from the families Liliaceae, Haemodoraceae, Myrtaceae, Thymelaeaceae, Proteaceae, Goodeniaceae and Rutaceae. Twenty-seven of the 28 species rooted in IVS medium at equal or better rates than in M1. In three cases Actinodium cunninghamii, one of the Pimelea physodes genotypes and one of the Eriostemon australasius genotypes shoots did not root in M1 but showed good root development in IVS medium. With few exceptions average root length and number in microcuttings rooted in IVS was superior to those in agar medium. To further test the resilience of the hypothesis, it was tested on nodal microcuttings of lentil which are recalcitrant to root in vitro (Chapter 5). The veracity of a published conclusion that inverted lentil microcuttings (with their base in the air) root better because of their altered polarity was also examined. It was found that, as is the case for many species, roots initiated and grew only at the proximal end of the microcutting regardless of its orientation. When the proximal end was in agar (a hypoxic environment) the rooting percentage was low (925%) even when the orientation of the microcutting was altered by inverting the culture tube. In contrast, when the proximal end of the microcutting was in an aerobic environment (from the shoot being placed upside down in agar medium or placed normally or upside down in an aerated medium) rooting percentages were higher (62100%). Given that Stage 2 microcuttings are prepared with the objective to root and acclimatise them to nursery conditions, the duration of this activity becomes important as it can impact on plant quality and costs. The pulsing protocol and the length of time that Stage 3 cultures remain in the culture room during the rooting phase is a component of the unit cost of production of each rooted microcutting. Initially a 7-day IBA pulse was used after which the pulsed microcuttings were transferred to IVS to root. Chapter 6 shows that the pulsing period can be shortened to one day or replaced with a single auxin dip while still achieving high rooting percentages and maintaining plant quality. These materials handling improvements go some way to realising the logistical benefits of ex vitro rooting but without compromising the positive influences of hygiene and a stable environment of the in vitro environment.

APA, Harvard, Vancouver, ISO, and other styles

35

com, cwebster82@gmail, and Craig Graham Webster. "Characterisation of Hardenbergia mosaic virus and development of microarrays for detecting viruses in plants." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20081021.103144.

Full text

Abstract:

A virus causing chlorosis and leaf distortion in the Western Australian endemic legume Hardenbergia comptoniana was detected by biological indexing to Chenopodium quinoa and Nicotiana benthamiana. Enzyme linked immuno-sorbent assay (ELISA) using general Potyvirus antiserum and amplification by reverse transcription polymerase chain reaction (RT-PCR) with degenerate primers indicated that it was a species of Potyvirus. It was confirmed as an unknown member of the genus Potyvirus by comparing its coat protein sequence with those of other potyviruses. The name Hardenbergia mosaic virus (HarMV) is proposed for this new virus species. Isolates of HarMV were collected from 13 sites, covering much of the natural range of its host. An experimental host range was determined using nine virus isolates tested against plants from 11 species in three families. Its infectivity on three leguminous species important in agriculture (Lupinus angustifolius, L. luteus and Trifolium subterraneum) was established. The nucleotide (nt) sequences of the coat proteins (CP) of 28 isolates determined there was 24.1- 27.6% diversity with the closest known relative, Passion fruit woodiness virus (PWV). Studies of the nucleotide sequences of the CP showed that there was considerable intra-species divergence (mean 13.5%, maximum 20.5%) despite its relatively small geographical distribution and single known natural host. The observed broad diversity strongly suggests long genetic isolation and that HarMV evolved in the region where it was collected. An examination of its phylogeny showed that 28 isolates clustered into eight clades with high bootstrap support (6.2-20.5% inter-clade diversity). Isolates collected at locations distant to the Perth metropolitan area (Margaret River and Seabird) diverged more from isolates collected in the metropolitan area (15.4-21.1% nucleotide sequence diversity). This virus represents the first endemic species to be characterised from Western Australia. Differences in pathogenicity and symptoms induced on key host species were seen between isolates belonging to different phylogenetic clades. Phylogenetic analysis confirmed the inclusion of HarMV within the Bean common mosaic virus group of the potyviruses and also defined a previously unreported subgroup of six previously described Potyvirus species (Clitoria virus Y, Hibbertia virus Y, PWV, Siratro 1 virus Y, and Siratro 2 virus Y), from Australia, which is further evidence for a prolonged period of genetic isolation. Both in relation to detection of strains of HarMV, and considering the broader issues of biosecurity and parallel detection of plant viruses, a microarray based detection system was established. To optimise conditions for the development of microarrays for virus detection poly-L-lysine (PLL) coated microscope slides produced in the laboratory were compared to commercially produced PowerMatrix slides (Full Moon BioSystems). Variables tested for PLL slide production were: choice of printing buffer, probe concentration, method of immobilisation and slide blocking; and in particular the print buffer and immobilisation method had the greatest effect on the quality of PLL microarray slides. Slides printed on PLL surfaces in a high salt buffer (3x Saline sodium citrate) supplemented with 1.5M betaine and immobilised at 42oC overnight retained the highest amounts of probe DNA of the methods tested. Qualitative comparisons of the two showed more probe was retained on PowerMatrix slides which were also more reliable and consistent than the PLL slides. Probes were designed for eight different virus species and six distinct strains of HarMV to test the potential to use microarrays to distinguish between them. Probes were designed to detect potyviruses at the genus, species and strain levels. Although there was evidence of non-specific hybridisation, the Potyvirus array was used to identify six strains of HarMV by hybridisation to species specific probes. Additionally the array was used to identify three other species of Potyvirus: Bean yellow mosaic virus, PWV and Passiflora foetida virus Y, following amplification with polyvalent PCR primers. In further microarray tests, using labelled first strand cDNA of Potato virus X (PVX) and Potato virus Y (PVY) on an array, PVX was strongly detected in leaves known to be infected, but PVY was only weakly detected in infected leaves. Three methods of pre-amplification of virus nucleic acid before hybridisation to the array were investigated to improve the sensitivity of the assay. Two of the methods, Klenow amplification and randomly primed PCR, amplified the target virus; as confirmed by real time PCR. Of the methods tested only randomly primed PCR improved the sensitivity of the microarray. The best amplification method used genus-specific primers with adaptor sequences. This method when tested by real time PCR showed a 3.7Ct reduction for PVX and 16.8Ct for PVY. The microarray correctly identified both viruses. In this work the first virus (HarMV) endemic to Western Australia was identified, and microarray methods were developed both to identify HarMV and other plant viruses of economic importance. The microarray approach, with further development, may be applicable as a means of identifying incursions of new viruses in a biosecurity situation.

APA, Harvard, Vancouver, ISO, and other styles

36

Brennan, R. F. "Zinc application and its availability /." Access via Murdoch University Digital Theses Project, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050602.142302.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Fracaro, Antonio Augusto [UNESP]. "Aplicação de ethephon em videira 'Niagara Rosada' (Vitis labrusca L.) visando produção na entressafra do Estado de São Paulo." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/105186.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:33:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-12-02Bitstream added on 2014-06-13T19:44:34Z : No. of bitstreams: 1 fracaro_aa_dr_jabo.pdf: 924092 bytes, checksum: 53fa7d51e3e6f4744e2563f9c1463ec6 (MD5)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Para a produção de uva na entressafra (setembro-outubro), é necessário que a poda seja realizada em período de provável ocorrência de baixas temperaturas, o que prejudica a emissão e desenvolvimento de brotos. Embasado em trabalho anterior, objetivou-se desenvolver uma técnica para viabilizar a emissão e desenvolvimento das brotações do cv. Niagara Rosada, mesmo em condições desfavoráveis com temperaturas abaixo de 10 ºC. Os experimentos foram conduzidos em vinhedos comerciais, na região de Jales-SP. Foram testadas quatro concentrações de ethephon (0; 720; 1.440 e 2.160 mg.L-1), aplicado de maio a junho, via foliar antes da poda de produção, em seis distintos experimentos, sendo três em 2001 e três em 2002. Verificou-se que a aplicação de ethephon promoveu o desfolhamento das videiras, principalmente nas concentrações de 1.440 e 2.160 mg.L-1. A aplicação em plantas pouco enfolhadas e/ou em período sem ocorrência de baixas temperaturas,não produziu resultados estatisticamente significativos na produção. Porém, observou-se um aumento na emissão e no desenvolvimento dos brotos nas concentrações mais elevadas. A aplicação de ethephon na concentração de 2.160 mg.L-1 em videiras com enfolhamento superior a 70% e temperaturas abaixo de 10 ºC, propiciou resultados excelentes no que se refere ao maior número de gemas brotadas, ao maior desenvolvimento dos ramos (comprimento e diâmetro) e a maior produção. O uso de ethephon não alterou o período da poda à floração, os teores de sólidos solúveis totais e a acidez total titulável mas, proporcionou aumento no comprimento e peso dos cachos e das bagas, na largura dos cachos e no diâmetro das bagas, melhorando a qualidade da uva.
For off-season grape production (September-October), pruning it is necessary in period of probable occurrence of low temperatures, what damages the emission and development of sprouts. Based in previous work, it was developed a technique to make possible the emission and development the sprout of the grape 'Niagara Rosada', even though unfavorable conditions of climate. These studies were carried out at commercial vineyards, in region of Jales, SP, Brazil. Four levels of ethephon (0; 720; 1,440 and 2,160 mg.L-1), applied from May to June, on leaves before the frutification pruning, in six experiments, on 2001 and three on 2002. It was observed that application of ethephon promoted defoliation of the grapevines, mainly in levels of 1,440 and 2,160 mg.L-1. The application in plants with less leaves and/or period without occurrence of low temperatures, did not produce significant results in the production. However, a trend of increase in emission and development of sprouts when higher levels of ethephon was observed. The application of ethephon (2,160 mg.L-1) on grapevines with more that 70% of leaves, in period of occurrence of lower temperatures (smaller 10 ºC), propitiated excellent results regarding the number of sprouted buds, shoot growth (length and diameter) and production. The use of ethephon did not modify the duration of the period from pruning to flowering, the total soluble solids and titrabre concentration acidity, but increased the length, diameter, the width and mass of the clusters and berries, improving the grape quality.

APA, Harvard, Vancouver, ISO, and other styles

38

Ye, Zhengqian. "Effect of low temperature on boron nutrition of oilseed rape and sunflower." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060510.154332.

Full text

Abstract:

Several reports appear in the literature linking low temperature damage in plants with boron (B) deficiency and alleviation of low temperature injury with B application has been reported in some crops and trees. These results imply that low temperature might increase plant B requirements, beside the reduction of B uptake by plant roots, or that low B tissues might be more sensitive to cold temperature damage than B adequate tissues. In controlled experiments, it has been shown that low root zone temperature (RZT) induces B deficiency in cassava, a tropical root crop. Apart from this, there are few definitive detailed investigations on low temperature effects on B nutrition of plants, including temperate species which are more tolerant of low temperature. Winter oilseed rape (Brassica napus L.), a crop sensitive to low B supply, is a major crop in the middle and lower Yangtse river basin, China, where low B soils are widespread. Appearance of B deficiency in oilseed rape often coincides with cold weather during its winter and spring growth. However, the incidence and severity of B deficiency of oilseed rape plants and the efficacy of B fertilization varies from year to year and location to location in ways that are not explained simply by differences in cultivar, agronomy or soil B levels. Low temperature is probably one of the important environmental factors influencing growth and yield of oilseed rape in relation to B nutrition. Therefore,the objective of the studies in this thesis was to investigate mechanisms of low temperature effects on B nutrition of plants with emphasis on oilseed rape. Field and glasshouse experiments were carried out and the physiological basis of plant response to B at different air and root temperatures is discussed. A field experiment with oilseed rape cv. Zheyouyou 2 was carried out on a red soil (Hapludult, US Soil Taxonomy) with low B availability in Zhejiang province, China. Canopy covers made from transparent plastic sheets, which increased night temperatures by up to 1.5 oC around shoots for 15 days in early February, strongly increased shoot dry weight at all levels of B supply. Furthermore, covering plants increased shoot dry weight of B deficient plants without increasing their leaf B concentration. This suggests that internal B requirements were decreased by canopy covering, possibly due to higher temperatures within the canopy. Experiments conducted to investigate the effect of RZT (10 and 20n oC) on oilseed rape cv. Hyola 42 response to B in solution culture, in summer and winter, showed that regardless of canopy conditions, low RZT (10 oC) promoted the distribution of shoot B towards the actively growing leaves, especially when B supply was low. At low B supply, B deficiency symptoms appeared later at 10 oC than 20 oC RZT and B concentrations in the youngest fully opened leaves (YOL) were higher in plants grown at RZT of 10 oC than that at 20 oC. Growth of plant dry weight (DW) was not affected by RZT in the summer but was greatly reduced at 10 oC than 20 oC in winter. In B adequate plants, shoot to root ratio (S/R ratio) was not affected by RZT regardless of canopy conditions. By contrast, S/R ratio was smaller in low B plants at 10 oC than 20 oC. In addition, low RZT delayed occurrence of plant B deficiency symptoms regardless of plants¡¦ pre-treatment RZT (either 10 or 20 oC). These results appeared to contradict the response to low RZT found in previous studies with cassava. In a subsequent experiment, low RZT of 5 oC not only greatly reduced plant DW production of oilseed rape, but also accentuated plant B deficiency. Partitioning of B into the young growing shoots was also depressed and a significant decrease of B concentration in the youngest shoot parts was caused by 5 oC RZT in comparison with that at the control RZT (10 oC). Similar results were also observed in sunflower (Helianthus annuus L. cv. Hysun 25). But B deficiency symptoms in sunflower were induced by RZT as high as 12 oC, when plants were supplied with 0.25 £gM B, whilst these plants were free from B deficiency at warmer RZT (17 - 27 oC). Higher external B concentrations were required at such RZT (Chilling temperature) for plant growth free from B deficiency. Therefore, there is a RZT threshold below which an increased response to B is expected in plants of oilseed rape and sunflower. And in the range of chilling RZT, the external B requirement for shoot growth increased with lower RZT. The threshold RZT was considerably higher in the chilling-sensitive plant species, sunflower, than in oilseed rape, a chilling-resistant plant species. At chilling RZT, leaf functioning was impaired by low B supply as measured by potassium (K) leakage from the youngest mature leaf blade (YML) of sunflower, whereas it was much less directly affected by RZT, and there was no effect of RZT on B- adequate plants. By contrast to leaves, root function was impaired more by chilling RZT than low B. Despite their different threshold RZT, in both oilseed rape and sunflower, the rates of B uptake (BUR) and B translocation from root to shoot (BTR) were dramatically depressed by chilling RZT especially at low B supply (0.2 £gM B): being only 30% of those at the control (5 oC vs 10 oC RZT) in oilseed rape and 33% (10 oC vs 20 oC RZT) in sunflower, respectively. By contrast, there was little or no difference over a range of warmer RZT (10 - 20 oC for oilseed rape, and 20 ¡V 27 oC for sunflower). It is predicted that higher rates of B application will be required for plant growth when soil temperature is below a critical threshold, which is between 5 and 10 oC for oilseed rape, and about 17 oC for sunflower, respectively. Below the threshold RZT plant B deficiency was induced and accentuated due to impairment of B translocation into growing shoot parts besides the decrease of B uptake rate and B transport rate and greater shoot to root ratio. In comparison with RZT, little is known about causal mechanisms linking cold air temperature and B nutrition. Experiments in this thesis showed not only B transport to the shoot was strongly reduced by low night air temperature during a 6 day period (11.719.4 vs 15.5 ¡V 23.5 oC), but also that an overnight chilling (at 0 oC) could cause more severe injury to low B than adequate B leaves of oilseed rape plants, expressed by higher solute leakage, in comparison with control (at 10 oC). Moreover, after chilling treatment, solute leakage from low B leaves was increased by exposure to light, which suggests that low temperature injury to leaves in low B plants after a freezing night in the field is at least partly a consequence of light induced damage of leaves. In summary, at chilling temperature, B uptake, transport and partitioning into growing shoots are strongly impaired, and B use efficiency in the growing tissues might be reduced as well. Low temperature contributes to plant B deficiency also by increasing S/R ratio, so that shoot B demand is not satisfied by available B. Furthermore, low air temperature might increase the internal B requirement for shoot growth. To further understand mechanisms of low temperature, especially the air temperature, effects on plant responses to B, more research is needed, such as the relationship between low temperature and B incorporation into cell walls which may play an important role in leaf tolerance to chilling temperature.

APA, Harvard, Vancouver, ISO, and other styles

39

com, harriehofstede@yahoo, and Henricus T. Hofstede. "Use of bauxite refining residue to reduce the mobility of heavy metals in municipal waste compost." Murdoch University, 1994. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.143422.

Full text

Abstract:

Use of bauxite refining residue to reduce the mobility of heavy metals in municipal waste compost. Due to the adverse environmental impact of landfills and the lack of space for nearby population centres an unprecedented interest has developed in waste recycling with the objective to reduce the volume of waste disposed. Generally organic matter represents the largest fraction in the domestic waste stream including food, garden and paper waste. In the past efforts have been made to process this organic fraction into muniapal compost.However contamination of the compost with heavy metals has in many cases resulted in the lack of suitable markets and subsequent closure of compost facilities. A study was undertaken and aimed at reducing the concentration and mobility of heavy metals in municipal compost. Bauxite refining residue ha; a high capacity to immobilise metals in soils through precipitation, cation exchange and chemisorption (Fe- and Al- oxides). The first step in the study was to assess the metal adsorption capacity of red mud by equilibrating red mud with metal solutions. Metal removal from solution proved very high. Subsequently, the effect of red mud addition to municipal compost was studied in relation to metal mobility. In particular the interaction of metals with the mobile soluble organic fraction, the humic and fulvic acids, was investigated. It was found that most metals remained in the insoluble humin fraction and the metals in solution remained complexed to the soluble organic fraction. Red mud appeared to be able to adsorp fulvic and humic acids and thus indirectly immobilise the metals in solution. Red mud did not appear to be able to transfer metals from the organic fraction to the mineral red mud fraction. ft was kypothesised that, in order for the metals to be adsorped to red mud, the red mud needed to be present in the organic waste prior to composting. Metal adsorption to red mud is a rapid chemical reaction while metal complexation to the organic fraction takes a number of weeks, since it must be sufficiently oxidised to contain functional groups. In order to verify this hypothesis, an installation with seven incubators was developed which allowed composting to be undertaken under computer controlled conditions and monitored for temperature, airflow and carbon dioxide respiration. The incubators were filled with 10 kg of a mixture of grass clippings and sawdust. The first incubator functioned as a control. The contents of the rest of the incubators were spiked with the following metals: Cd, Cr, Cu, Ni, Pb and Zn. In addition the contents of the 3rd - 7th incubators were amended with an increasing percentage of red mud, respectively 10,20,25,30 and 40 % by weight. After the mixture was composted, the metal mobility was reduced by approx. 80 - 99 %, depending on the metal. The mobility was assessed as leachable and plant available in relation to the total metal content. Red mud did not affect the composting process if < 40% red mud was added. The next step was to compost municipal organic waste in a pilot plant (capacity 5 m3) using batches with and without red mud. Mixed waste was collected from 150 households and the glass, metal and plastic fractions were removed bx- manual sorting. The rest was composted. The red mud - compost had a relatively lower metal content and a reduced metal mobility compared to compost without red mud. The red mud - compost also had a 300 times higher pH buffer capacity and 90%less soluble organic matter. The addition of red mud prior to composting was found to reduce the concentration and mobility of metals in compost, improve the quality of compost as a soil conditioner, increased the resistance of the organic fraction against further breakdown and this process thus adds value to both red mud and organic waste.

APA, Harvard, Vancouver, ISO, and other styles

40

Waters, Ormonde Dominick Creagh. "Metabolism and infection in the Stagonospora nodorum-wheat pathosystem /." Murdoch University Digital Theses Program, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090409.123159.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Salequzzaman, Md. "Can tidal power promote sustainable integrated coastal development in Bangladesh? /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040428.151218.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Menezes, Anna Christina Passos 1966. "Reguladores vegetais na brotação, características dos cachos e produtividade da videira cv. Itália no Vale do São Francisco, BA /." Botucatu : [s.n.], 2007. http://hdl.handle.net/11449/103238.

Full text

Abstract:

Orientador: João Domingos Rodrigues
Banca: Elizabeth Orika Ono
Banca: Manuel Abílio de Queiróz
Banca: Teresinha Costa Silveira de Albuquerque
Banca: José Carlos Fachinello
Resumo: O presente trabalho foi conduzido na Fazenda Cooperyama - Juazeiro- BA, com o objetivo de estudar a eficiência de reguladores vegetais na brotação e características dos cachos da uva 'Itália'. Para avaliação da brotação das gemas foram efetuadas observações em dias alternados determinando-se o número de brotos. Os tratamentos considerados foram: T1: Testemunha; T2: 2,45 g L-1 de cianamida hidrogenada; T3: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico; T4: 0,09 mg L-1 de cinetina, 0,05 mg L-1 de ácido giberélico e 0,05 mg L-1 de ácido indolilbutírico; T5: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico + 10 kg de nitrogênio e 9 kg de Ca ha-1; T6: 0,09 mg L-1 de cinetina, 0,05mg L-1 de ácido giberélico e 0,05 mg L-1 de ácido indolilbutírico + 10 kg de nitrogênio e 9 kg de cálcio ha-1; T7: 0,1 mg L-1 de cinetina + 10 kg de nitrogênio e 9 kg de cálcio ha-1; T8: 0,2 mg L-1 de cinetina + 10 kg de nitrogênio e 9 kg de cálcio ha-1 e T9: 0,045 mg L-1 de cinetina, 0,025mg L-1 de ácido giberélico e 0,025 mg L-1 de ácido indolilbutírico + 2,45 g L-1 de cianamida hidrogenada + 10 kg de nitrogênio e 9 kg de cálcio ha-1. Para caracterização dos cachos foram avaliados a massa, comprimento e largura média dos cachos; massa, comprimento e diâmetro médio das bagas; massa seca dos engaços; número médio de bagas/cacho; número médio de cachos/planta; produtividade média/planta; sólidos solúveis, acidez titulável e ratio. Os tratamentos considerados foram 2,5; 20 e 20 mg L-1 de ácido giberélico em pó; 0,019; 0,25; 0,038; 0,5; 0,076; 1,0 mL L-1 de ácido giberélico líquido; 0,01; 0,05, 0,075; 0,1, 0,5% de cinetina, ácido giberélico e ácido indolilbutírico, respectivamente e 1,5; 3,0; 6,0; 20,0; 40,0; 80,0 mL L-1 de ...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The trial was carried out in the farm Cooperyama - Juazeiro-BA, with the objective to study the efficiency of plant growth regulators on sprouting and on the cluster characteristics of 'Itália' grapes. To evaluate the bud sprouting, observations were done on alternate days and the number of sprouts were registered. The treatments considered were: T1: Control; T2: 2,45 g L-1of the hydrogen cyanamide ; T3: 0,045 mg L-1of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1of indolilbutiric acid; T4: 0,09 mg L-1 of kinetin, 0,05 mg L-1 of gibberellic acid the 0,05 mg L-1 of indolilbutiric acid; T5: 0,045 mg L-1 of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolilbutiric acid 0,045 mg L-1 of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolilbutiric acid + 10 kg the nitrogen e 9 kg the calcium ha-1; T6: 0,09 mg L-1 of kinetin, 0,05 mg L-1 of gibberellic acid the 0,05 mg L-1 of indolilbutiric acid + 10 kg the nitrogen e 9 kg the calcium ha-1; T7: 0,1 mg L-1 of kinetin + 10 kg the nitrogen e 9 kg the calcium ha-1; T8: 0,2 mg L-1 of kinetin + 10 kg the nitrogen e 9 kg the calcium ha-1 e T9: 0,045 mg L-1of kinetin, 0,025 mg L-1 of gibberellic acid the 0,025 mg L-1 of indolbutiric acid + 2,45 g L-1of the hydrogen cyanamide + 10 kg the nitrogen e 9 kg the calcium ha-1. For cluster characterization, weight, length and average width of clusters; weight, length and average diameter of berries; dry weight of rachis; average number of berries/cluster; average number of clusters/plant; average productivity/plant; soluble solids content; acidity and ratio were evaluated. The treatments considered were 2.5; 20 and 20 mg L -1 of gibberellic acid; 0.019; 0.25; 0.038; 0.5; 0.076; 1.0 mL L-1 of gibberellic acid liquid of 0.01; 0.05, 0.075; 0.1, 0.5 % of kinetin, gibberellic acid the indolilbutiric acid, respectivemant and 1.5; 3.0; 6.0; 20.0; ...(Complete abstract click electronic access below)
Doutor

APA, Harvard, Vancouver, ISO, and other styles

43

Franco, André Andrade. "Resíduos de deltametrina, aplicada em diferentes formulações, em compartimentos da cultura do pepino (Cucumis sativus L.) tutorado e ação do inseticida no controle da broca-das-cucurbitáceas Diaphania nitidalis (Cramer, 1782) (Lepidoptera: Crambidae)." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-11112004-140048/.

Full text

Abstract:

O desenvolvimento da agricultura, a modernização dos meios dos cultivos, buscando atender a um mercado exigente, tem-se baseado no uso de insumos agrícolas para garantir a produção de alta qualidade e de quantidade. Tais culturas demandam o uso de pesticidas, cujos resíduos, principalmente em hortaliças e frutas, são motivo de preocupação com a saúde dos consumidores e de operários que necessitam retornar às culturas tratadas com esses agrotóxicos. Os objetivos deste estudo foram: a) estudar o comportamento dos resíduos de deltametrina, de diferentes formulações, em frutos, folhas e solo; b) avaliar os resíduos deslocáveis do inseticida nas folhas, como ponto de partida para estudos de exposição ocupacional; c) correlacionar os teores de deltametrina nos frutos com o controle da broca-das-cucurbitáceas e d) correlacionar os resíduos nos frutos com o limite máximo de resíduo (LMR) e o intervalo de segurança (período de carência) estabelecidos pela legislação. Os tratamentos foram: a) testemunha; b) três aplicações da formulação em concentrado emulsionável Decis 25 CE na dosagem de 30 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); c) três aplicações da formulação em concentrado emulsionável Decis Ultra 100 CE na dosagem de 7,5 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); e d) três aplicações da formulação em suspensão concentrada Decis 200 SC na dosagem de 3,75 mL de p.c.100 L-1 de água (0,75 g i.a. deltametrina 100 L-1 de água). As amostras de fruto e de solo foram colhidas a (-1); zero; 1; 3; 5 e 7 dias após a última aplicação; as amostras de folhas e as de para estudos de resíduos deslocáveis nestas foram tomadas a (-1); zero; 1; 3; 5; 7 e 14 dias. O método analítico constou da extração dos resíduos de deltametrina de acetato de etila, limpeza dos extratos por técnica de cromatografia de permeação em gel (GPC), com eluição feita com uma mistura de acetato de etila/ciclohexano. A determinação quantitativa por cromatografia de gás. Para a avaliação da eficiência do inseticida, foram feitas seis levantamentos de infestação, determinando-se a porcentagem de frutos brocados. Os resultados indicaram que os resíduos de deltametrina no fruto, embora em baixos níveis, encontravam-se acima do LMR (0,03 mg.kg-1), mesmo um dia após o término do intervalo de segurança (2 dias) para as formulações do inseticida. Nas folhas, os resíduos resultantes das aplicações da formulação SC foram sempre maiores do que ambas CE (10-20 vezes), sendo de 15-80 vezes mais altas do que nos frutos. No solo, os resíduos foram também baixos (0,01-0,05 mg.kg-1), e semelhantes nas três formulações, entretanto, com baixa dissipação. Os resíduos deslocáveis de deltametrina nas folhas foram muito elevados quando de aplicações em SC, comparadas com as formulações CE (4-20 vezes), com valores de meias-vida de 2,8; 3,8 e 32,2 dias, respectivamente para as formulações Decis 25 CE, Decis Ultra 100 CE e Decis 200 SC. O inseticida, nas formulações em que foi aplicado, foi eficiente no controle da praga durante todo o período de avaliação.
The agriculture development, the modernization of cultivation means, trying to meet a demanding market, has been based on the use of agricultural supplies to assure a high quality and quantity production. Such crops demand the use of pesticides, whose residues, especially in fruit and vegetable production, raise worries about the consumers health and of the workers who need to return to the treated crop with these pesticides. The objectives of this study were: a) to study the behavior of deltamethrin residues applied in different formulations in fruits, leaves and soil; b) to evaluate the dislodgeable residues of the insecticide in leaves, as a starting point for occupational exposure studies; c) to correlate deltamethrin concentration in fruit with the pickleworm control and d) to correlate residues in fruit with the maximum residue level (MRL) and the safety interval established by the legislation. The treatments were: a) control ; b) three applications of the emulsifiable concentrate formulation Decis 25 CE.100-1 at the dosage of 30 mL of c.p.100 L-1 water (0.75 g a.i. deltamethrin.100L-1 water); c) three applications of the emulsifiable formulation of Decis Ultra 100 CE at the dosage of 7.5 mL of p.c.100 L-1 water (0.75 g a.i. deltamethrin.100. L-1 water) and d) three applications of the concentrate suspension formulation Decis 200 SC at the dosage of 3.75 mL of c.p.100.L-1 water (0.75 g a.i. deltamethrin 100L-1 water). The fruit and soil samples were taken at (-1); zero; 1; 3; 5 and 7 days after the last application; leaf samples and also those for the studies of dislodgeable residues on them were collected at (-1); zero; 1; 3; 5; 7 and 14 days after the last application. The analytical method consisted of the extraction of deltamethrin residues in ethyl acetate, clean-up of the extracts by gel permeation chromatography (GPC), with elutition made with a mixture of ethyl acetate/cyclohexane. The quantitative determination was made by gas chromatograph. To evaluate the insecticide efficacy six infestation surveys were carried out, based on the percentage of infested fruit . The results indicate that the deltamethrin residues in fruit, though in low levels, were found higher than the MRL (0.03 mg.kg-1), for the three insecticide formulations, even a day after the end of the safety interval (2 days). In the leaves the resulting residues of the applications of SC formulation were always bigger than both CE (10-20 times), being 15-80 times higher in the fruits. In the soil, the residues were also low (0.01-0.05 mg kg-1), and similar in the three formulations, however with low dissipation. The dislodgeable residues of deltamethrin in leaves were higher in SC as compared to both CE (4-20 times), with half-life values of 2.8; 3.8 and 32.2 days, respectively for the formulation Decis 25 CE, Decis Ultra 100 CE and Decis 200 SC. The insecticide in the formulations applied was efficient in the pest control during the whole evaluation period.

APA, Harvard, Vancouver, ISO, and other styles

44

Lowe, Rohan George Thomas. "Sporulation of Stagonospora nodorum /." Access via Murdoch University Digital Theses Project, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071101.221432.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Souza, Dariane Sagaseta de Oliveira. "Suscetibilidade de Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) à proteína inseticida Cry1F de Bacillus thuringiensis Berliner no Brasil." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-25062013-165208/.

Full text

Abstract:

A broca-da-cana Diatraeasaccharalis(Fabricius) é uma das pragas-alvo do milho geneticamente modificado que expressagene(s) que codifica(m) proteína(s) de BacillusthuringiensisBerliner(milho Bt) no Brasil. Para estabelecer estratégias proativas de manejo de resistência, os objetivos do presente trabalho foram (1)estabelecer linhas-básicas de suscetibilidade à proteína Cry1F de B. thuringiensisem populações de D. saccharalis coletadas nas principais regiões produtoras de milho no Brasil na safra de 2010/2011, (2) realizar monitoramentoda suscetibilidade de populações de D. saccharalis na safra 2011/2012 e (3) avaliar a atividade biológica do milho Bt (evento TC1507) em diferentes estádios fenológicos no controle de D. saccharalis em condições laboratoriais. Para a caracterização das linhas-básicas de suscetibilidade foram realizados bioensaios com a proteína purificada Cry1F aplicada superficialmente em dieta artificial.As CL50 de Cry1F estimadas variaram de 0,47 a 7,02 ng de Cry1F/ cm2 dieta artificial para as populações avaliadas (variação de ?15 vezes). Foi definida e validada a concentração diagnóstica de 112 ng de Cry1F/cm²,baseada na estimativa da CL99 das populações testadas para o monitoramento da suscetibilidade. A avaliação da atividade biológica de milho Bt (evento TC1507) foi realizada com dois híbridos (Pioneer 30F35 e Dow 2B688) nos estádios fenológicos V3, V6 e V9 e em duas épocas de plantio. Alta atividade de controle de D. saccharalis foi obtida para os dois híbridos de milho Bt nos diferentes estádios fenológicos e épocas de plantio. Portanto, verificou-se que a espécie D. saccharalis é altamente suscetível à proteína Cry1F. Contudo, a implementação de estratégias de manejo da resistência é de fundamental importância para preservar a vida útil da tecnologia de milho Bt como importante ferramenta em programas de MIP.
The sugarcane borer Diatraeasaccharalis (Fabricius) is one of the target pests of genetically modified maizeexpressinggenes that code for insecticidal proteins from Bacillus thuringiensis Berliner (Bt maize) in Brazil. To implement proactive resistance management strategies, we leaded studies (1) to establish baseline susceptibility to Cry1F protein from B. thuringiensis in populations of D. saccharalis collected from major maize production regions in Brazil during 2010/2011 growing season, (2) to leadsusceptibility monitoring in populations of D. saccharalis collected in 2011/2012 growing season, and (3) to assess the biological activity of Bt maize (event TC1507) at different growth stages forD. saccharaliscontrol under laboratory conditions. The baseline susceptibility wascharacterizedwith purified protein Cry1F applied superficially on artificial diet. The estimatesof LC50 of Cry1F ranged from 0.47 to 7.02 ng Cry1F/cm2of artificial diet for the populations evaluated (? 15-fold variation).A diagnostic concentration of 112 ng Cry1F/cm ² was defined and validated for monitoring the susceptibility based on estimation of CL99 of all tested populations. The biological activity of Bt maize (event TC1507) was assessed by using two hybrids (Pioneer 30F35 and Dow 2B688) at growth stages V3, V6 and V9 and two planting seasons. High level of D. saccharaliscontrol was obtained for the twoBt maize hybrids at different growth stages and planting seasons. Therefore, we conclude that D. saccharalis is highly susceptible to Cry1F protein. However, implementation of insect resistance management strategies is essentialin order to preserve the lifetime of Bttechnology as an important tool in IPM programs.

APA, Harvard, Vancouver, ISO, and other styles

46

Gomes, Sebastião Antonio. "Conservação de hastes porta-borbulhas de citros de diferentes idades, em vários períodos de armazenamento." Universidade Federal de Viçosa, 2004. http://www.locus.ufv.br/handle/123456789/10489.

Full text

Abstract:

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-06-02T13:22:28Z No. of bitstreams: 1 texto completo.pdf: 1744259 bytes, checksum: d8164ccbe5e63c6ac8da1af073a77b08 (MD5)
Made available in DSpace on 2017-06-02T13:22:28Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1744259 bytes, checksum: d8164ccbe5e63c6ac8da1af073a77b08 (MD5) Previous issue date: 2004-09-23
Este trabalho teve por objetivo determinar o efeito do período de armazenamento e da idade das hastes porta-borbulhas de citros na viabilidade das borbulhas e no crescimento das brotações. As hastes porta-borbulhas em estudo foram dos cultivares laranjeiras 'Baianinha' e 'Pêra Rio' e limeira ácida 'Tahiti'. As hastes foram desinfestadas (com hipoclorito de sódio a 1% de cloro ativo), e tratadas com 2,4-D (20 μmol L-1) (para fixação dos pecíolos) e fungicidas [Cercobin 700 PM (1,0 g L-1 de água) mais Captan Hokko® (1,0 g L-1 de água)], e logo após foram acondicionadas em sacos de polietileno transparente de baixa densidade e armazenadas em câmara fria a 5 ± 1 °C, durante 60 dias para o 'Tahiti' e 60 e 120 dias para os outros cultivares. Para a limeira ácida 'Tahiti' utilizou-se o delineamento em blocos casualizados com disposição dos tratamentos em esquema fatorial, cujos fatores foram período de armazenamento (com dois níveis: 0 e 60 dias) e idade das hastes (com três níveis: 100, 120 e 140 dias). Para as laranjeiras 'Baianinha' e 'Pêra Rio' utilizou-se o delineamento em blocos casualizados com disposição dos tratamentos em esquema fatorial, cujos fatores foram cultivares (com dois níveis: 'Baianinha' e 'Pêra Rio'), período de armazenamento (com três níveis: 0, 60 e 120 dias) e idade das hastes (com três níveis: 100, 120 e 140 dias). Em ambos os casos foram utilizadas quatro repetições e a unidade experimental foi constituída por seis hastes porta-borbulhas. Foram avaliadas a viabilidade das borbulhas, o crescimento das brotações, teor de matéria seca, teores de açúcares solúveis totais e amido. O aumento do período de conservação das hastes reduziu a viabilidade das borbulhas para os cultivares 'Baianinha' e 'Tahiti'; a viabilidade das borbulhas aumentou com a idade das hastes para a 'Pêra Rio'. A idade das hastes não influenciou o crescimento das brotações, e a altura das brotações foi maior nos enxertos provenientes de hastes que não foram armazenadas para os três cultivares. Constatou-se para os cultivares laranjeiras 'Baianinha' e 'Pêra Rio' que não houve influência do armazenamento e da idade das hastes no teor de matéria seca, e para o 'Tahiti' ocorreu aumento da matéria seca com o aumento da idade das hastes. Observou-se que para os açúcares solúveis totais ocorreu menor perda para as hastes com idade de 140 dias para a 'Baianinha'; para a 'Pêra Rio' não houve efeito da idade sobre o teor de açúcares solúveis totais; para o 'Tahiti' observou-se decréscimo no teor de açúcares com o aumento do armazenamento. Para o amido, os maiores teores ocorreram para as hastes com idade de 120 e 140 dias e armazenadas por 60 dias, para a 'Baianinha'; para a 'Pêra Rio' ocorreu menor perda para as hastes com idade de 100 dias; para o 'Tahiti' observou-se maior teor de amido para as hastes que não foram armazenadas. A variável viabilidade das borbulhas não se correlacionou com os teores de açúcares solúveis totais e amido para os três cultivares.
This work aimed to determine the effect of storage period and age of budsticks of citrus cultivars on bud viability and shoot growth. The budsticks studied originated from the orange cultivars 'Baianinha' and 'Pêra Rio' and the acid lime cultivar 'Tahiti'. The sticks were disinfested (with sodium hypochloride at 1% active chlorine), and treated with 2,4-D (20 μmol L-1) (for petiole fixation) and fungicides [Cercobin 700 PM (1.0 g L-1 of water) plus Captan Hokko® (1.0 g L-1 water)], being immediately placed in low density transparent polyethylene bags and stored in cold chamber at 5 ± 1 °C over 60 days for 'Tahiti' and 60 and 120 days for the other cultivars. For the acid lime cultivar 'Tahiti', a randomized block design was used with the treatments arranged in a factorial scheme, the factors being the storage periods (0 and 60 days) and stick age (100, 120 and 140 days). For the orange cultivars 'Baianinha' and 'Pêra Rio', a randomized block design was used with the treatments in a factorial scheme, with the factors being the cultivars ('Baianinha' and 'Pêra Rio'), storage periods (0, 60 and 120 days) and stick age (100, 120 and 140 days). In both cases, four repetitions were used with the experimental unit being constituted by six budsticks. Bud viability, shoot growth, dry matter content, total soluble sugar and starch contents were evaluated. Increased sticks conservation period reduced bud viability for the cultivars 'Baianinha' and 'Tahiti'; bud viability increased with sticks age for 'Pêra Rio'. Sticks age did not influence shoot growth, with shoot height being higher in grafts originating from stick that had not been stored for the three cultivars. For the orange cultivars 'Baianinha' and 'Pêra Rio', stick storage and age did not have any effect on dry matter content, and for 'Tahiti', dry matter increased with the increase of stick age. A smaller loss of total soluble sugars was observed for stick at 140 days of age for 'Baianinha'; 'for Pêra Rio,' no age effect was observed on total soluble sugar content, for 'Tahiti, 'there was a decrease in the sugar content with increase of the storage period. The highest starch contents occurred for sticks at 120 and 140 days of age, stored for 60 days for 'Baianinha'; for 'Pêra Rio,' a smaller loss occurred for 100-day -old stick; for 'Tahiti, ' higher starch content was observed for sticks that had not been stored. The variable bud viability did not correlate with the contents of total soluble sugars and starch for the three cultivars.

APA, Harvard, Vancouver, ISO, and other styles

47

Bowman, Tiffanny R. "The Cascading Effects of Invasive Grasses in North American Deserts: The Interactions of Fire, Plants, and Small Mammals." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5646.

Full text

Abstract:

The landscapes of the Great Basin and Mojave Deserts are changing due to plant invasion. Highly flammable invasive grasses increase the size and frequency of fire causing a cascade of effects through the plant and animal communities. One of the most influential animal groups in desert systems is small mammals. We sought to learn how small mammals are impacted by fire and how their influence on the plant community differs between burned and unburned habitat. Small mammals did not have higher rates of mortality as a direct result of a controlled burn. In the Great Basin, there were short-term reductions in abundance, richness, and diversity of the small mammal community in burned plots. In the Mojave, species richness and diversity increased in burned plots shortly after fire and no abundance differences were detected. These results correspond with our prediction based on the dominant small mammal species at each site. Small mammals are primarily granivores; however, they also have strong impacts on the plant community via folivory. We tested for small mammal impacts on seedling survival in burned and unburned habitat. Small mammal access, burned vs. unburned habitat, and plant species were all important determinants of survival. Small mammals greatly reduced survival at both sites in burned and unburned habitat and often had a stronger impact in unburned than burned plots. Accounting for small mammal folivory may be a crucial step in successful post-fire rehabilitation. Finally, we used seed trays to test how small mammals influence the persistence of seed on the landscape. Small mammals reduced persistence of an invasive and native plant species in the Great Basin in 2012, yet a year later when small mammal abundance was reduced, no small mammal effect was observed. In the Mojave, persistence was reduced for the majority of species both years of the study. Small mammals did not appear to avoid seed of invasive plant species as we had predicted and may be important consumers reducing the reproductive potential of these invaders. If small mammals do prefer non-native seedlings over natives and are also consuming non-native seed, they may be greatly reducing the presence of non-natives both on the unburned landscape as well as after fire. Non-native consumption by small mammals could aid in the biotic resistance of these desert ecosystems. This research further enforces the important role that small mammals play as consumers, dispersers, and regulators of the plant community.

APA, Harvard, Vancouver, ISO, and other styles

48

Lucas, Anne. "Water stress and disease development in Eucalyptus marginata (jarrah) infected with Phytophthora cinnamomi." Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040820.13290.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Mulyati. "Zinc requirements of transplanted oilseed rape." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060109.135933.

Full text

Abstract:

Transplanting is a common practice for many horticultural crops and some field crops. Recently, transplanted oilseed rape (Brassica napus L.) crops have been reported to be sensitive to zinc (Zn) deficiency. However, Zn nutrition in transplanted field crops has not been investigated in detail. The objectives of this present research were to investigate whether transplanting increases external Zn requirements of transplanted oilseed rape, and the mechanisms of root function, growth and Zn uptake after transplanting including rhizosphere modification capacity by plant roots. The second objective was to examine the relative effects of root pruning and transplanting on Zn responses of oilseed rape, and the third objective was to determine external and internal Zn requirements of transplanted oilseed rape for diagnosing and predicting Zn deficiency. An experiment on a low Zn sand (DTPA extractable Zn 0.14 mg kg-1) was set up to determine whether transplanted oilseed rape had a higher Zn requirement than that of direct-sown plants. Low Zn supply depressed shoot dry weight, however, root growth was relatively more strongly suppressed than shoots. Maximum root dry weight required much higher external Zn for transplanted plants compared to direct-sown plants, whilst shoot dry weight required a similarly low external Zn supply. In addition, transplanted plants were sensitive to zinc deficiency during the early post-transplanting growth, and the response weakened as the plants recovered from root injury or transplanting stress. However, the transplanted plants also experienced root pruning before transplanting and so in this experiment the higher Zn requirement could have been due to root pruning or transplanting or both. A further experiment was undertaken to determine the comparative external Zn requirements of direct-sown and transplanted plants in well-stirred chelate-buffered solution culture where a rhizosphere effect on plant availability of Zn forms is absent and the effects of poor root-soil contact on post-transplanting growth are minimized. In solution culture at the same level of Zn supplied, direct- sown plants produced higher shoot and root dry matter and greater root length than those of transplanted plants. However, since a higher external Zn requirement was found for transplanted plants in buffered solution culture than for direct- sown plants, it was concluded that the higher Zn requirement was not related to decreased rhizosphere modification, to greater demand for Zn or to poor root-solution contact, but rather to the time required for transplanted plants to recover from transplanting and root injury. The recovery of root function in solution culture was more rapid than that in soil culture and expressed as a higher Zn requirement for shoot as well as root growth. It suggested that the delay in root recovery in soil culture was due to slower absorption of Zn from the soil after transplanting than was the case in solution culture. Chelate-buffered nutrient solution culture and harvesting plants successively at 5 day intervals until 25 days after transplanting was used to examine the mechanisms of the recovery of root growth and function. In this experiment, the external Zn requirement of transplanted plants was investigated with unpruned or pruned root systems. Plants with unpruned root system and sufficient Zn supply exhibited faster recovery from transplanting than those with pruned root system plants. The results suggest that root pruning impaired Zn uptake by plant roots and slowed down the root and shoot growth after transplanting. Increased solution Zn partly alleviated the effects of root pruning and presumably this is a major reason why transplanted oilseed rape had a high external Zn requirement. However, root pruning also appeared to impair water uptake, and may have suppressed shoot growth through sequestering carbon for new root growth and through decreased phytohormone production by roots. Since rapid root recovery of transplanted plants is essential for successful of growth in the field, Zn application to the nursery bed was explored as a starter fertilizer to stimulate root growth after transplanting. The objective of this experiment was to determine whether increasing the seedbed Zn would stimulate new root growth of transplanted oilseed rape, and therefore would alleviate the need for increased external Zn for post-transplanting growth. Results showed that adequate Zn concentration in the seedbed promoted the post-transplanting growth by stimulating the new root growth especially increased root length, and also hastened the recovery of root systems. However, high Zn concentration at transplanting still had a more dominant effect in stimulating the new root growth of oilseed rape after transplanting. The final experiment was set up using rhizobags with three rates of Zn supply and unpruned or pruned root systems. The purpose of this study was to investigate the chemical change in the rhizosphere and non-rhizosphere or bulk soil and its relationship to the recovery of root function after transplanting, and also to identify and quantify the organic acids in soil extracts of direct-sown and transplanted plants. The rhizosphere soil pH was lower than that of non-rhizosphere soil, and the decrease of soil pH was suggested as the mechanism of the increase of Zn availability and mobility in the rhizosphere soil. Direct-sown plants were more efficient in utilizing Zn than those of transplanted plants especially compared to those of plants with pruned root system. Zinc deficient plants excreted higher concentration of organic acids particularly citric acid, suggesting this was a mechanism of Zn mobilization and Zn uptake by roots of oilseed rape. The main implications of the present study for the management of Zn nutrition of transplanted crops were: the need to increase the Zn application to crops in the nursery and at transplanting compared to direct-sown plants; the possibility that external requirements of other nutrients will be greater in transplanted crops also requires further consideration; and in cropping systems where transplanting is practised, greater attention should be given to the avoidance of root damage during the transplanting.

APA, Harvard, Vancouver, ISO, and other styles

50

Loss, Edenes Maria Schroll. "Dinâmica da dormência e conteúdo de carboidratos em pessegueiros em clima subtropical úmido." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2341.

Full text

Abstract:

CNPq
A região Sul do Brasil cultiva espécies frutíferas de clima temperado, principalmente pessegueiros, macieiras, videiras e ameixeiras com relativo sucesso. Entretanto, a produção está fortemente vinculada a técnica de quebra de dormência a base de produtos químicos, outrora, proibidos em países importadores de frutas brasileiras. Há necessidade de se conhecer melhor a dinâmica da dormência dessas frutíferas, principalmente do pessegueiro, para que se desenvolva novas técnicas e cultivares adaptadas a regiões subtropicais. O objetivo deste trabalho foi de avaliar e compreender os mecanismos de entrada e saída da dormência de gemas, bem como avaliar o teor de carboidratos nos ramos e nas gemas de pessegueiros das cultivares Santa Áurea e Tropic Beauty, que possuem intermediária e baixa necessidade de frio, respectivamente. Para isso, foram investigadas a evolução do estado de dormência pelo teste de nós isolados e pelo teste de Tabuenca, o estado de hidratação dos tecidos, a atividade da enzima alfa amilase e a concentração de açúcares em diferentes partes de ramos produtivos (brindilas) coletados no período de abril a agosto. Não foi observada instalação de endodormência verdadeira nas gemas de Tropic Beauty e Santa Áurea, também não foi observado período de ecodormência típico, sendo que a paralisação observada é atribuída a paradormência. Os testes biológicos (Teste de um só nó e Teste de Tabuenca) são eficientes em separar as cultivares quanto ao seu estado de dormência. A porção distal dos ramos possui maior ou igual concentração de açúcares solúveis (sacarose, hexoses) que a base, sugerindo que esses possam estar relacionados com a acrotomia, principalmente em Santa Áurea. Não foi observado relação real entre o conteúdo de carboidrato com a dormência, variando conforme a mudança da temperatura ambiente.
The South region of Brazil grows temperate fruit species, especially peaches, apples, vines and plums trees with relative success. However, the production is strongly linked to the rest-breaking chemicals technique, once prohibit in importing countries receiving Brazilian fruits. There is a necessity to know better the dynamics of dormancy of these fruit trees, mainly the peach, for the development of new techniques and cultivars adapted to subtropical regions. The aim of this work was to evaluate and to comprehend the mechanisms of entry and interruption of dormancy of the fruit buds, as well as to evaluate the carbohydrates content in branches and buds of peach trees cultivars Santa Áurea e Tropic Beauty, which have intermediate and low cold necessity, respectively. In this regard, it were investigated the dormancy status evolution using the isolated nodes and Tabuenca tests, the tissues hydration, the alpha-amylase enzyme activity and the sugars concentration in several portions of productive branches collected from April to August. No endodormence period was observed on the buds of Tropic Beauty e Santa Áurea; also, no typical ecodormence period was observed, whereas the observed downtime is attributed to paradormence. The biologic tests (isolated nodes and Tabuenca tests) were efficient on the cultivars division due to their dormancy status. The distal portion of the branches has the higher or equivalent soluble sugars concentration (sucrose, hexoses) than the base, suggesting that they may be related to acrotomy, mainly in Santa Áurea. No real relation among carbohydrates content and dormancy, varying according to the changes in the ambient temperature.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Brotes de plantas'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles