Dissertations / Theses: 'Seedling seeds'

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Welling, P. (Pirjo). "Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland." Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:951426861X.

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Abstract The aims were to examine the importance of regeneration by seeds, the influence of plant traits and disturbances, and the role of seed-seedling conflicts in regeneration and in the determination of vegetation structure. The study was carried out at in a subarctic alpine area (Kilpisjärvi 69°01'N 20°50E', Finland). Seed bank and seedling densities were high in many plant communities (ranges 99 -1109 viable seeds/m2 and 0.2-227 seedlings/m2, respectively). Effective seedling recruitment is reflected in vegetation as a high proportion of plants with poor or no vegetative reproduction ability. This development may take place in meadows and snowbeds where herbs (e.g. Gnaphalium supinum, Sibbaldia procumbens, Veronica alpina and Viola biflora) are abundant. On the other hand, the low proportion of these plants in heath vegetation reflects ineffective seedling recruitment. Floristic similarities between the consecutive phases in the regeneration pathway may be low despite effective seedling recruitment. Clonality, large and small seed sizes and appendaged diaspores limit the movement of species from phase to phase. Generally, disturbances facilitate effective regeneration by seeds. Grazing promotes species with large seed banks and is therefore one reason for high seed bank densities. Freezing and melting processes negate a negative influence of altitude on seed bank densities in the phase of seedlings. However, if disturbances are severe and continuous and the soil is compact, unstable or dry, disturbances are not beneficial. The same is true if there is a shift in the species composition of seedlings from gaps to closed vegetation. This phenomenon occurred in a rich meadow. Seed-seedling conflicts limit regeneration by seeds in low-herb snowbeds and Ranunculus glacialis-Gymnomitrion snowbeds. Vegetative reproduction and infrequent pulses of seedling recruitment negate an influence of short-term seedling recruitment on the spatial structure of vegetation. Extreme conditions, such as low temperatures, instability of the soil and late snowmelt modify the influence of factors that are important in more moderate conditions. To conclude, all transitions limit regeneration by seeds. However, favourable conditions (e.g. moist conditions in a meadow) partly eliminate the obstacles against seedling emergence. Regeneration by seeds therefore has a major impact on the dynamics and structure of vegetation. In heath vegetation, where bare soils are dry and the moss cover is thick, large seed banks and seed rains do not guarantee effective seedling recruitment. The regeneration process is reduced in the early phases, and plants that reproduce primarily by seeds have a minor role in vegetation. The accumulation of seed banks is effective in these circumstances.

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Magnitskiy, Stanislav V. "Controlling seedling height by treating seeds with plant growth regulators." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1101741472.

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Thesis (Ph. D.)--Ohio State University, 2004. Title from first page of PDF file. Document formatted into pages; contains xix, 157 p.; also includes graphics. Includes bibliographical references (p. 147-157).

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Kamboozia, Jafar. "Seedling vigour in winter grain legumes." Title page, table of contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phk152.pdf.

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Cordazzo, Cesar Vieira. "Comparative population studies of four dominant plants of southern Brazilian coastal dunes." Thesis, University of East Anglia, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241475.

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5

De, Villiers Rykie (Rykie Jacoba). "The influence of chemical seed treatment on germination, seedling survival and yield of canola." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50163.

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Thesis (MScAgric)--University of Stellenbosch, 2004. ENGLISH ABSTRACT: The influence of chemical seed treatments on the germination, seedling survival and yield of canola (cv. Varola 44) was investigated in a series of incubation studies, glasshouse experiments, as well as field trials in the canola producing areas in the Western Cape Province. Incubation experiments were conducted to compare germination and seedling growth of untreated (control) seed with that of seed treated at different application rates (0.5, 1.0 and 2.0 times the recommended) of Cruiser® and SA-combination (which consists of Thiulin® at 0.5g a.i.; Apron® at 0.0815 g a.i.; Gaucho® at 0.6125 g a.i. and Rovral® at 0.9975 g a.i.). The results indicated that seed treatment (all rates of SA-combination and highest rate of Cruiser) delayed germination and seedling growth, especially if the seed was subjected to the Accelerated Ageing Test. Glasshouse studies with pasteurised soil at different water contents, seed sources (storage periods) and planting depths confirmed the phytotoxic effects of the chemical seed treatments in the absence of soil borne pathogens. From the results it became clear that extreme water conditions (very wet or dry) increased the suppressing effect on germination and seedling growth, but that no phytotoxic reactions occurred in moist (favourable soil water conditions) soil, regardless of application rate of the chemicals used, planting depth and seed source. In a second glasshouse experiment conducted in moist soil (kept at 50% of field water capacity to prevent any toxic effects) from seven different localities that were naturally infested with pathogens, both chemicals proved to be effective where soil borne pathogens (Rhizocfonia so/ani and Pythium spp.) occurred. No clear trend could however be found due to either chemical or application rates used. Finally, field trials were conducted to study the effect of chemical seed treatments on the plant populations and yield of canola planted in different row widths (17 and 34 cm) and seeding rates (3, 5 and 7 kq.ha'). Results showed that treated seeds produced more plants.rn" and yielded more than untreated seeds at Roodebloem Experimental Farm, while the highest seeding rate produced significantly more plants.rn" (Roodebloem and Langgewens Experimental Farms), but not significantly higher yields than the lowest seeding rate at the same locality. Although row width did not have an effect on plant population, yield (Roodebloem 2003) was significantly less at the wider (34 cm) rows. As in earlier experiments, no consistent differences between the two chemicals used were found. These results clearly illustrated both the negative (in the absence of pathogens) and positive (where soil borne pathogens do occur) effects that chemical seed treatments may have on the germination, seedling growth and even yield of canola under local environmental and soil conditions. Because no significant differences were found between the chemicals used, both chemicals should be regarded as efficient. More research, especially under field conditions and with more cultivars, is needed before the registration of a chemical for seed treatment could be considered. AFRIKAANSE OPSOMMING: Die invloed van chemiese saadbehandeling op die ontkieming, saailing oorlewing en opbrengs van canola (cv. Varola 44) is ondersoek in 'n reeks inkubasie studies, glashuis eksperimente en veldproewe in die canolaproduserende gebiede in die Wes Kaap Provinsie. Inkubasie eksperimente is uitgevoer om die ontkieming en saailing groei van onbehandelde (kontrole) saad te vergelyk met dié van saad wat behandel is teen verskillende dosisse (0.5, 1.0 en 2.0 keer die aanbevole) van Cruiser® en SA-kombinasie (wat bestaan uit Thiulin® teen 0.5g a.i.; Apron® teen 0.0815 g a.i.; Gaucho® teen 0.6125 g a.i. en Rovral® teen 0.9975 g a.i.). Die resultate het aangedui dat saadbehandeling (vir alle dosisse van SAkombinasie en die hoogste dosis van Cruiser) ontkieming en saailing groei vertraag, veral wanneer die saad onderwerp was aan die Versnelde Verouderings Toets. Glashuis studies met gepasteuriseerde grond by verskillende waterinhoude, saad bronne (stoor periodes) en plantdieptes, het die fitotoksiese effekte van die chemiese saadbehandelings bevestig in die afwesigheid van grondgedraagde patogene. Vanuit die resultate het dit duidelik geword dat ekstreme water toestande (baie nat of droog) die onderdrukkende effek op ontkieming en saailinggroei verhoog het, maar dat geen fitotoksiese reaksies plaasgevind het in klam (gunstige grondwater toestande) grond nie, ongeag die dosisse of chemikalieë gebruik, plantdiepte en saad bron. In 'n tweede glashuis eksperiment uitgevoer in klam grond (gehou by 50% van veldwaterkapasiteit om toksiese effekte te voorkom) van sewe lokaliteite wat natuurlik besmet was met patogene, was beide chemikalië effektief waar grondgedraagde patogene (Rhizoctonia so/ani en Pythium spp.) voorgekom het. Geen duidelike tendens is egter waargeneem vir enige van die chemikalieë of dosisse nie. Laastens is veldproewe uitgevoer om die effek van chemiese saadbehandelings op plant populasies en opbrengs te bepaal van canola geplant in verskillende rywydtes (17 en 34 cm) en saaidigthede (3, 5 en 7 kg.ha-1). Resultate het aangedui dat behandelde saad meer plante.rn" produseer en 'n groter opbrengs lewer as onbehandelde saad by Roodebloem Eksperimentele Plaas, terwyl die hoogste saaidigtheid betekenisvol meer plante.m" (Roodebloem en Langgewens Eksperimentele Plase), maar nie betekenisvol hoër opbrengste gelewer het as die laagste saaidigtheid by dieselfde lokaliteit nie. AI het rywydte nie 'n effek op plant populasie gehad nie, was opbrengs (Roodebloem 2003) betekenisvol minder by die wyer (34 cm) rye. Soos in vroeëre eksperimente is geen konsekwente verskille tussen die twee chemikalieë gevind nie. Hierdie resultate illustreer duidelik beide negatiewe (in die afwesigheid van grondgedraagde patogene) en positiewe (in die aanwesigheid van grondgedraagde patogene) effekte wat chemiese saadbehandelings op ontkieming, saailing groei en selfs opbrengs van canola onder plaaslike omgewings en grondtoestande kan hê. Omdat geen betekenisvolle verskille tussen die chemikalieë gevind is nie, moet beide chemikalieë as doeltreffend aanvaar word. Meer navorsing, veralonder veldtoestande en met meer kultivars, is egter nodig voordat die registrasie van 'n chemiese middel vir saadbehandeling oorweeg kan word.

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Mogollones, Barrera Sol C. "Seed dispersal, seedling emergence and bird community structure in a human-modified landscape mosaic in Sri Lanka." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=202126.

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Weatherall-Thomas, Clayton Richard. "Seed dynamics and seedling survival in mainland thicket of the Eastern Cape." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1048.

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Subtropical Thicket is the dominant vegetation biome in the Eastern Cape. Little regeneration through seedlings has been observed in Thicket. This is of serious concern, as Thicket has been degraded over large areas of its distribution. An understanding of the seed dynamics is necessary for any restoration project. A number of possible causes for the lack of seedlings were therefore investigated. Study sites were best classified according to the biogeographical regions of the Subtropical Thicket Ecosystem Planning (STEP) project. The seed bank of Thicket is dissimilar to the aboveground vegetation, as it lacks woody species and is dominated by herbs and grasses, making little contribution to the regeneration of Thicket species. An increase in canopy cover resulted in lower soil and air temperatures, as well as light, and an increase in litter depth. Seedling abundance and species richness increases with mean annual rainfall, with woody seedlings being dominant in the higher rainfall areas, and succulent species in the lower rainfall regions. Anemochorous species dominated the germinable seed bank, and zoochorous species were more prevalent underneath the canopy, compared to open areas, an indication of active seed dispersal. No germination was recorded in many Thicket species, and dormancy mechanisms were lacking in many of the species that did germinate. Immersion in hot water increased germination in the hard seeds of Acacia karroo, whereas shade enhanced germination in small seeded Burchellia bubalina. The response of seedlings of four Thicket species with varying distribution to shade and drought was studied. Ptaeroxylon obliquum and Aloe africana are drought tolerant species, whereas Burchellia bubalina and Rhus dentata were intolerant to low soil moisture. All four species were able to grow in deep shade, although Rhus dentata would be classified as a shade avoider, unlike the other three species that are shade tolerant. This results in the four species having different regeneration niches. It was concluded that dispersal and the lack of “safe sites” for seedlings were the main limitations to seedling establishment in Mainland Thicket.

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Van, Etten Erica. "Seedling recruitment of large-seeded tropical trees planted as seeds in the Ecuadorian Amazon." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025046.

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9

Socolowski, Fabio. "Ecologia germinativa, relações alométricas e o efeito da massa das sementes de Tecoma stans L. Juss. ex Kunth (Bignoniaceae) sobre a emergência e desenvolvimento das plântulas /." Rio Claro : [s.n.], 2007. http://hdl.handle.net/11449/100667.

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Orientador: Massanori Takaki Banca: João Domingos Rodrigues Banca: Silvio Moure Cícero Banca: José Marcos Barbosa Banca: Márcia Balistiero Figliolia Resumo: Este estudo teve como objetivo avaliar a relação entre a massa e características morfométricas de frutos e sementes de Tecoma stans, bem como relacionar a massa das sementes a suas características morfológicas, utilizando paquímetro e imagens de raios X, e fisiológicas, através da germinação, emergência e desenvolvimento inicial de suas plântulas, sob duas condições de luminosidade . a pleno sol e sombra. Além disso, também foram avaliados os efeitos de diferentes condições de temperatura e luz constantes, em laboratório, e em ambiente natural no sol e na sombra na germinação e emergência das plântulas. A massa dos frutos apresentou relações lineares significativas e positivas com suas características morfológicas e de produção de sementes. As relações entre a massa das sementes e suas características morfológicas foram positivas e significativas, porém na forma de uma função potência, sendo esta relação mais evidente com a largura do embrião. A massa das sementes também esteve relacionada a determinadas anomalias do desenvolvimento embrionário, observadas nas imagens de raios X. A germinação, a emergência e o desenvolvimento inicial das plântulas foram significativamente afetados pela massa das sementes, porém somente durante os três primeiros meses de desenvolvimento no ambiente de sol. A temperatura apresentou efeito na germinação e suas sementes germinaram tanto na luz quanto no escuro, contudo a emergência e sobrevivência das plântulas no ambiente de sol foi superior em relação ao observado na sombra. Abstract: This study had the objective to evaluate the relationship between the mass and the morphometric characteristics of Tecoma stans fruits and seeds, as well as to relate the seed mass with its morphometric characteristics, utilizing caliper and X-ray images, and physiological characteristics, thought germination, emergency and seedlings initial development, under two conditions of light - at the sun and shade. More than, also were evaluated the effects of different conditions of constant temperature and light, under laboratory, and natural environment under sun and shade in the germination and emergency of the seedlings. The fruit mass presented positive, significative linear relationship with his morphological characteristics and with its seed production characteristics. The relationship between seed mass and its morphological characteristics were positive and significative, nevertheless with the model (shape) of power function, being the relationship more clear with the embryo width. The seed mass also was related to determinate anomalies of the embryo development that could be observed in the X-ray images. The germination, the seedling emergence and the initial seedling development were significative affected by seed mass, but only in the firth three months of development at the sun environment. The temperature affected Tecoma stans seed germination in both light and darkness environment, however the seedlings emergency and survival was greater at the sun environment than shade. Doutor

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Sekharan, Soja. "Aged soybean (Glycine max [L.] Merrill) seeds – their physiology and vigor assessment." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1135809134.

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Silva, Josué Bispo da. "Testes para avaliar o potencial fisiológico de sementes de beterraba /." Jaboticabal : [s.n.], 2006. http://hdl.handle.net/11449/105115.

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Orientador: Roberval Daiton Vieira Banca: Teresinha de Jesus Deléo Rodrigues Banca: Arthur Bernardes Cecílio Filho Banca: Júlio Marcos Filho Banca: Ana Dionisia da Luz Coelho Novembre Resumo: O uso de testes de vigor é imprescindível na avaliação do potencial fisiológico das sementes produzidas e comercializadas por uma empresa. O trabalho, dividido em duas etapas, teve por objetivo estudar diferentes testes para avaliar o potencial fisiológico de sementes de beterraba. Com base nos resultados, concluiu-se que os testes de EA, EASS-20, EASS-40 e DC podem ser utilizados para avaliar o potencial fisiológico de sementes de beterraba; o uso de soluções salinas apresenta vantagem sobre o procedimento tradicional; o ajuste do TA das sementes no teste de deterioração controlada deve ser feito pelo método do substrato úmido. Abstract: The use of vigor tests is essential to evaluate the physiological potential of seed lots produced and selled by a company. The work, separated in two stages, aimed to study different vigor tests to evaluate the physiological potential of beetroot seeds. With base in the results, it was concluded that EA, EASS-20, EASS-40 and DC tests can be used to evaluate the physiological potential of beet seeds; the use of solutions presents advantage on the traditional procedure; the adjustment of seed MC in the controlled deterioration test would be done by the method of humid substratum. Doutor

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Pamuk, Gunnar Sven. "Controlling water dynamics in Scots pine (Pinus sylvestris L.) seeds before and during seedling emergence /." Umeå : Dept. of Silviculture, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/s305.pdf.

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Hepburn, Henry A. "Investigations into the potential use of physical-chemical properties of crop seeds as indicators of seed germinability and early seedling growth." Thesis, University of Aberdeen, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333439.

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Electrical conductivity of soakwater was measured for individual seeds from a range of crop species. Conductivity was expected to increase with loss of germinability since deterioration is thought to degrade membrane permeability in seeds leading to increased loss of cellular contents during imbibition. Non-terminable seeds had, on average, higher soakwater conductivities per seed than germinable seeds. Heavier seeds tended to have higher conductivities per seed than lighter seeds, partly explaining overlaps between the soakwater conductivity distributions of germination categories. Re-expressing conductivity on a unit weight basis reduced the effect of seed size (weight) and led to improved differentiation between seed germination categories, but their conductivity distributions still overlapped. Genera, cultivar or seed lot, and soak time also influenced soakwater conductivity and the differentiation between seed germination categories. Tetrazolium vital staining of radish and onion seeds revealed that small areas of damage on crucial tissue sites could cause non-germinability with low soakwater conductivity. Seeds with extensive damage away from these sites could be germinable with high soakwater conductivities. Such instances accounted for some of the overlap in conductivity distributions. Larger graded seeds were more susceptible to imbibition damage than smaller graded seeds. The smallest hand graded seeds of onion and Brussels sprout showed reduced germination percentage and seedling growth compared with larger graded seeds. K+ was present in soakwater of individual pea and soyabean seeds in far greater amounts than Mg2+ or Ca2+ and, along with UV absorbance at 210nm and 260nm, tended to have higher values for non-germinable compared with germinable seeds. These soakwater measurements were no more effective than electrical conductivity at differentiating between seed germination categories.

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Ye, Nenghui. "Stress perception and ABA signaling in rice seed germination and seedling establishment." HKBU Institutional Repository, 2011. https://repository.hkbu.edu.hk/etd_ra/1305.

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Liu, Rui. "Regulation and molecular signaling during seed germination and seedling establishment of arabidopsis in response to abiotic stresses." HKBU Institutional Repository, 2013. https://repository.hkbu.edu.hk/etd_oa/101.

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Plants regulate many physiological processes in response to adverse environmental stresses. This study focused on the seed germination and seedling establishment stage and investigated the molecular signaling events when abiotic stresses, such as osmotic, water and temperature, were applied. Seeds of Arabidopsis, mutants or wild type, were used to identify the signaling components. Cold-pretreatment (stratification) is widely used to break seed dormancy and improve germination rate. Stratification at 4. significantly broke the seed dormancy of Arabidopsis in wild-type, cyp707a2, sleepy1 and sleepy1/cyp707a2, but not in ga3ox1. Stratification and exogenous ABA treatment strongly enhanced the expression and the activity of a-amylase in the freshly harvested seeds among the wild-type and those mutants, which have relatively high ABA content. Similarly, the expression of RGL2 and ABI5 were also substantially suppressed by stratification. These results suggest that stratification firstly leads to GA biosynthesis and unlocks the inhibition of RGL2 on the expression of a-amylase. Stratification also relieves the inhibition of ABA on the germination process but the inhibition of ABA on seedling development is not affected. We have isolated an Arabidopsis mutant, dsptp1, which is hyposensitive to osmotic stress during seed germination and seedling establishment, indicated by exhibiting higher seed germination rate, lower inhibition in root elongation under osmotic stress, and more tolerance to drought compared with the wild type (Col0) plants. Osmotic stress and drought enhanced AtDsPTP1 expression in seed coats, the bases of rosette leaves and roots. Compared with the wild type, the dsptp1 mutant increased proline accumulation, reduced MDA content and ion leakage, and enhanced antioxidant enzyme activity under osmotic stress. AtDsPTP1 regulated the transcript levels of various dehydration responsive genes, ABA biosynthesis and metabolic enzyme gene under osmotic stress, resulting in reduced accumulation of ABA in dsptp1 mutant plants than wild type in response to osmotic stress. AtDsPTP1 also mediated the ABA signaling pathway under osmotic stress by suppressing the expression of ABI1 and enhancing the expression of the positive regulators ABI3 and ABI5 in ABA signaling. These data suggest that AtDsPTP1 positively regulates ABA accumulation and signaling during seed germination and seedling establishment in Arabidopsis under osmotic stress. To further investigate the regulation mechanism of DsPTP1 in osmotic stress and drought signaling, we analyzed the water holding capacity between wild type and dsptp1 mutant. The dsptp1 mutant exhibited enhanced water holding capacity compared to wild type under osmotic stress resulting from reduced water loss and increased relative water content, which shall contribute the osmotic and drought tolerance. To identify the signaling components, we investigated the activity of MAPKs under osmotic and drought stress and found that the DsPTP1 differentially regulates the activities of MAPK6 and a p38 MAPK, which is inferred as MAPK12 according to its molecular weight in Arabidopsis under osmotic and salt stress. However, there is no direct interaction between DsPTP1 and 20 MAPKs indicated by the results of the of specific interaction test. These results suggest that the differential regulation of MAPK6 and MAPK12 by DsPTP1 is indirect. In addition, we screened the interaction proteins of DsPTP1 under abiotic stress. Seventeen positive clones were acquired from the sequencing results. More work need to be done to confirmed the positive interactions and the signaling cascades. In summary, seed germination and seedling growth are closely regulated by environmental cues. This should be the result of evolutionary selection since successful new growth from the seed embryo depends on the sensitive perception of environmental conditions and effective regulation of many physiological processes that are involved. We have demonstrated that plant hormones, especially ABA, play central regulative roles during such regulations. Many other signaling components, such as protein kinases and phosphatases, are also involved. Identifying the detailed signaling pathways should be the focus of further research.

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Stone, Sandra Lee. "Triacylglycerol and carbohydrate metabolism in loblolly pine, Pinus taeda L., seeds during germination and early seedling growth." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ46925.pdf.

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Nelson, J. M., and C. C. Sharples. "Effect of Treatment of Lettuce Seeds with Fusicoccin and Other Growth Regulators on Seedling Emergence at High Temperature." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/214109.

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Lettuce stand problems in desert production areas are, in many instances, related to high seedbed temperatures and the use of seed coatings. We evaluated the use of fusicoccin and other growth regulators to improve the performance of naked and coated lettuce seeds at high temperature. Treatment of both naked and coated seeds with fusicoccin markedly increased the rate and total emergence of seedlings incubated at 35 °C for 10 hours alternating with 23 °C for 14 hours.

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Hosseini, Mohammad Khajeh. "The response of soybean seeds to the stresses of semi-arid environments during germination and early seedling growth." Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324912.

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Reduced water availability and salinity are two major environmental factors influencing crop establishment in semi-arid environments. Therefore the effect of reduced water availability using polyethylene glycol (PEG) 4000 solutions and of salinity (NaCl) on the germination of six soybean cultivars was examined. Cultivars differed in their response to reduced water availability and salinity and in their ability to recover from the stresses. A large increase in germination during a recovery period at 0 MPa following water stress suggested that PEG was not toxic whilst the failure of seeds to recover from high salinity revealed the toxic effects of NaCl. At the same water potential, germination in saline conditions was higher than that in PEG and the rate of water uptake by individual seeds was more rapid in NaCl solutions than in PEG. The most plausible explanation for the greater water uptake and germination in NaCl is that seeds accumulated salts which lowered their osmotic potential. The effects of NaCl on seedling growth were much greater when experiments were conducted in a hydroponic system compared with a paper towel method. However, analysis of the solutions soaking the paper towels revealed that 4.25 mMolal Ca2+ was available to the seeds in this system in saline conditions. This may have reduced Na+ uptake or provided a protective effect against Na+ toxicity. Germination (40%) was possible at a tissue Na+ concentration in the embryonic axis of 9.3mg g-1 FW whilst seedling growth was completely inhibited at a tissue Na+ concentration of 6.1 mg g-1 FW. Germination at higher tissue Na+ concentrations was associated with higher K++Ca2+ concentrations, suggesting that these ions may protect the seeds in the pregermination phase against salinity. A reduction in seed vigour due to ageing resulted in reduced germination under saline conditions compared to the germination of unaged seeds, but there was no significant interaction between salinity and seed ageing. However, unaged seeds showed a greater increase in germination after transfer to 0 MPa than did the aged seeds. Since both the site of ageing and the toxic effect of NaCl is the cell membrane, there may be additive effects of NaCl toxicity on cell membrane in aged seeds.

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Silva, Josué Bispo da [UNESP]. "Testes para avaliar o potencial fisiológico de sementes de beterraba." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/105115.

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Made available in DSpace on 2014-06-11T19:33:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-03-27Bitstream added on 2014-06-13T18:45:35Z : No. of bitstreams: 1 silva_jb_dr_jabo.pdf: 199072 bytes, checksum: 14fd74baadfa1ee3eebbb79f63e6a4fa (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) O uso de testes de vigor é imprescindível na avaliação do potencial fisiológico das sementes produzidas e comercializadas por uma empresa. O trabalho, dividido em duas etapas, teve por objetivo estudar diferentes testes para avaliar o potencial fisiológico de sementes de beterraba. Com base nos resultados, concluiu-se que os testes de EA, EASS-20, EASS-40 e DC podem ser utilizados para avaliar o potencial fisiológico de sementes de beterraba; o uso de soluções salinas apresenta vantagem sobre o procedimento tradicional; o ajuste do TA das sementes no teste de deterioração controlada deve ser feito pelo método do substrato úmido. The use of vigor tests is essential to evaluate the physiological potential of seed lots produced and selled by a company. The work, separated in two stages, aimed to study different vigor tests to evaluate the physiological potential of beetroot seeds. With base in the results, it was concluded that EA, EASS-20, EASS-40 and DC tests can be used to evaluate the physiological potential of beet seeds; the use of solutions presents advantage on the traditional procedure; the adjustment of seed MC in the controlled deterioration test would be done by the method of humid substratum.

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Almeida, JoÃo Paulo Nobre de. "Germination and seedling growth of amburana cearensis (AllemÃo) A.C. smith as a function the weight of seeds and abiotic factors." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13207.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico Given the needs of reclamation is increasing interest in the propagation of native species, which requires basic information about their germination characteristics and ecophysiological. The Amburana cearensis (AllemÃo) A.C. Smith known as cumaru is a species widely used for restoration of the landscape. The aim of this study was to investigate the germination and seedling growth of cumaru depending on the weight of the seeds under conditions of light, temperature, drought stress, as well as to determine the seed imbibition curve, internal morphology, chemical composition and quantification of the coumarin. Initially seeds were individually weighed and separated into three weight classes (light, medium and heavy), these being submitted to the determination of water content, thousand seeds weight and germination tests in two light conditions (presence and absence ) and six schemes temperatures (20, 25, 30, 35, 40, and 20-30 ÂC). In addition to these tests, it was determined the imbibition curve of each weight class and made assessment of drought stress tolerance under different potentials(-0.2, -0.4, -0.6, -0.8 and -1,0 MPa). The experiments were arranged in a completely randomized design in four replications for each treatment. For the internal morphology of seeds were used in cytochemistry usual techniques for the identification of the main structures and substances reserves. To visualize the coumarin in the seeds by NMR spectroscopy was used. The optimum conditions for seed germination occurred at 30 ÂC, which are insensitive to light and vigor seeds for light and medium. The best conditions for seedling growth occurred with the light and medium seeds at 25 and 30 ÂC and in the presence of light, with temperatures of 35 and 40 ÂC harmful. Light and medium seeds showed the same pattern of water absorption, while not reach the heavy phase III of the curve. The decrease in the water potential of the substrate affect the germination and growth of seedlings from seed medium and heavy compared to the light, and from -0.6 MPa in a condition strictly limiting seedling development. The chemical constituents present in the seeds of A. cearensis are quantitatively different depending on the weight of the seeds, and the heavy characterized by a high content of lipids. The NMR spectroscopy falls greater proportion of coumarin in seed extract heavy and medium, possibly affecting ecophysiological needs of the species A. cearensis. Diante das necessidades de recuperaÃÃo de Ãreas degradadas Ã crescente o interesse na propagaÃÃo de espÃcies florestais nativas, o que demanda informaÃÃes bÃsicas sobre as suas caracterÃsticas germinativas e ecofisiolÃgicas. A Amburana cearensis (AllemÃo) A.C. Smith conhecida como cumaru Ã uma espÃcie bastante utilizada para recomposiÃÃo da paisagem. O objetivo deste trabalho foi estudar a germinaÃÃo e o crescimento de plÃntulas de cumaru em funÃÃo do peso das sementes sob diferentes condiÃÃes de temperatura, luz, estresse hÃdrico, bem como determinar nas sementes a curva de embebiÃÃo, morfologia interna, composiÃÃo quÃmica e identificaÃÃo da cumarina. Inicialmente as sementes foram pesadas individualmente e separadas em trÃs classes de peso (leves, mÃdias e pesadas), sendo estas, submetidas Ã determinaÃÃo dos teores de Ãgua, peso de mil de sementes e a testes de germinaÃÃo em duas condiÃÃes de luz (presenÃa e ausÃncia) e seis regimes de temperatura (20, 25, 30, 35, 40 e 20-30ÂC). AlÃm destes ensaios, foi determinado a curva de embebiÃÃo de cada classe de peso e avaliaÃÃo da tolerÃncia ao estresse hÃdrico sob diferentes potenciais (-0,2, -0,4, -0,6, -0,8 e -1,0 MPa). Os experimentos foram dispostos em delineamento inteiramente casualizado com quatro repetiÃÃes para cada tratamento. Para a morfologia interna das sementes foram utilizadas tÃcnicas usuais em citoquÃmica para a identificaÃÃo das principais estruturas e substÃncias de reservas. Para a visualizaÃÃo da cumarina nas sementes foi utilizada a espectroscopia por RMN. As condiÃÃes Ãtimas para a germinaÃÃo das sementes ocorreu na temperatura de 30ÂC, sendo estas insensÃveis Ã luz e um maior vigor para sementes leves e mÃdias. As melhores condiÃÃes para o crescimento das plÃntulas ocorreram com as sementes leves e mÃdias nas temperaturas de 25 e 30ÂC e na presenÃa de luz, sendo as temperaturas de 35 e 40 ÂC prejudiciais. Sementes leves e mÃdias apresentam o mesmo padrÃo de absorÃÃo de Ãgua, enquanto as pesadas nÃo atingem a fase III da curva. O decrÃscimo do potencial hÃdrico do substrato prejudica a germinaÃÃo e o crescimento de plÃntulas oriundas de sementes mÃdias e pesadas em comparaÃÃo Ãs leves, sendo a partir de -0,6 MPa uma condiÃÃo estritamente limitante na formaÃÃo de plÃntulas. Os constituintes quÃmicos presentes nas sementes de A. cearensis sÃo quantitativamente diferenciados em funÃÃo do peso das sementes, sendo as pesadas caracterizadas por um elevado teor de lipÃdios. A espectroscopia por RMN releva uma maior proporÃÃo de cumarina no extrato de sementes pesadas e mÃdias, que possivelmente afetam as necessidades ecofisiolÃgicas da espÃcie A. cearensis.

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21

Bagatim, Amanda Garcia [UNESP]. "Temperatura e substrato na germinação de Physalis angulata L." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/150341.

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Agradecemos a compreensão. on 2017-04-17T18:59:55Z (GMT) Submitted by Amanda Garcia Bagatim (amanda_cr.aveiro@hotmail.com) on 2017-04-19T13:08:15Z No. of bitstreams: 1 Dissertação_Amanda (1) Repositório.pdf: 743946 bytes, checksum: 054f8890abe45a5e955680914731fee1 (MD5) Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-19T13:15:40Z (GMT) No. of bitstreams: 1 bagatim_ag_me_jabo.pdf: 743946 bytes, checksum: 054f8890abe45a5e955680914731fee1 (MD5) Made available in DSpace on 2017-04-19T13:15:40Z (GMT). No. of bitstreams: 1 bagatim_ag_me_jabo.pdf: 743946 bytes, checksum: 054f8890abe45a5e955680914731fee1 (MD5) Previous issue date: 2016-11-04 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Devido as escassas informações sobre as melhores condições para a produção de mudas de physalis no Brasil, este trabalho teve o objetivo de verificar a temperatura adequada para germinação, assim como o substrato mais eficiente para a emergência de plântulas de Physalis angulata L. As sementes após serem extraídas de frutos maduros, foram lavadas para a retirada de toda mucilagem e secas em temperatura ambiente (±25 ºC) por 24 horas. Após este período, estas foram colocadas em câmaras de germinação tipo B.O.D., com temperaturas controladas e submetidas a diferentes temperaturas: 20, 25, 30, 35 e 20-30 °C, para posterior avaliação da porcentagem de germinação, índice de velocidade de germinação e tempo médio de germinação. Um segundo experimento foi realizado testando diferentes substratos, onde foram utilizados: vermiculita textura fina, mistura de terra + areia + esterco de curral curtido (3:1:1), substrato comercial à base de casca de pinus e fibra de coco. As sementes após passarem pelo processo de limpeza e secagem descrito acima, foram semeadas em bandejas de polietileno e avaliadas quanto à porcentagem de emergência, índice de velocidade de emergência e tempo médio de emergência. Foram coletadas amostras aleatórias das plântulas e estas levadas para laboratório, onde foram avaliados: comprimento médio de parte aérea e raiz (cm), massas fresca e seca de raiz e parte aérea (gramas) e número de folhas. Para ambos os experimentos o delineamento foi o inteiramente casualizado (DIC), os resultados submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. De acordo com os resultados obtidos, não há influência dos substratos testados na germinação de sementes de Physalis angulata L., sendo o substrato comercial à base de casca de pinus o que proporcionou melhor desenvolvimento inicial das mudas. Já as melhores temperaturas para a germinação de sementes de physalis foram: alternada 20-30 ºC e constantes 30 e 35 ºC, com maiores índices de velocidade de germinação para a temperatura alternada 20-30 ºC. Due to the scarce information about the best conditions for the production of physalis seedlings in Brazil, this research had the objective to verify the adequate temperature for germination, as well as the most efficient substrate for the emergence of Physalis angulata L. seedlings. After being extracted from ripe fruits, seeds were washed to removal all the mucilage and dried at temperature ± 25 °C for 24 hours. After this period, the seeds were placed to germinate in chambers type BOD, with controlled temperatures: 20, 25, 30, 35 and 20-30 °C, for further evaluation of germination percentage, germination speed index and average germination time. A second experiment was carried out aiming to test different substrates: vermiculite fine texture, soil + sand mixture + tanned corral manure (3:1:1), commercial substrate with pine bark and coconut fiber. The seeds, after the cleaning and drying process described above, were seeded in polyethylene trays and evaluated for the percentage of emergence, rate of emergence and mean time of emergence. Random samples were collected from the seedlings and taken to the laboratory, evaluating: average length of shoot and root (cm), fresh and dry masses of root and shoot (grams) and number of leaves. For both experiments the design was completely randomized (DIC), the results submitted to the analysis of variance and the means compared by the Tukey test at 5% of probability. According to the results obtained, there is no influence of the substrates tested on the germination of seeds of Physalis angulata L., being the commercial substrate with pinus bark which provided better initial development of the seedlings. The best temperatures for the germination of physalis seeds were: alternated 20-30 ºC and constants 30 and 35 ºC, with higher rates of germination for the alternating temperature of 20-30 ºC. CNPq: 163880/2014-0

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22

Nicolai, Nancy Carol. "Plant community dynamics governed by red harvester ant (Pogonomyrmex barbatus) activities and their role as drought refugia in a semi-arid savanna." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2657.

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This study examined modifications made by Pogonomyrmex barbatus, by their processes of granivory and nest construction, to forb and grass dynamics under large-scale disturbances of fire, recent drought and long-term, large-mammalian herbivory using comparative studies, field experimental manipulations, and a simulation model on the Edwards Plateau, Texas. Ant nests are refugia for grass survival during extreme droughts as demonstrated during the drought of 1998 to 2002. Significantly greater cover of grasses and lower abundance and cover of forbs was found beside nests compared with surrounding habitat throughout the drought and recovery. Grasses near nests may be the seed source for surrounding habitats during recovery. Seeds were differentially collected among most forbs and grasses despite seed abundance. Harvest was significantly reduced in the fall relative to spring. During preference experiments, harvest differences were found between grazing treatments for two of four species, but only during the spring. High lipid content seeds were unpreferred in fall compared to high protein and carbohydrate content seeds. Granivory influences on seedling establishment were studied by comparing seedling recruitment among sown and naturally occurring seeds excluded and open to foragers. Exclosures were placed in three nest densities and two burn treatments. Seeds in exclosures produced significantly more seedlings than open arenas only during the first year of drought recovery. Densities of grasses and annual forbs were higher in open arenas the second year due to indirect effects of granivory. By reducing seeds ants release seedlings from competition. Sown seedling abundance was unaffected by colony density and fire. Colony density and distribution were influenced by topography, soil types, soil depth and woody cover, but not by historical grazing treatments. Cleared vegetation on nest disks impacted less than 1% of total surface area and losses were compensated by greater basal cover of grasses next to disks compared to surrounding habitats. Foraging areas influenced 17.3-73.6% of surface area and could diminish seed populations for potential seedlings. Model results agree with experimental observations that communities may be modified by P. barbatus presence due to differential responses of grass species to interaction between nests or granivory and rainfall amounts.

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Silva, Tatiana Maria da. "Seed biometrics, morphology seedlings and species of five initial growth fruit that occur in Northeastern Brazil." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14130.

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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior Brazilian native fruits are among the most tasty and nutritious in the world, being known only by the local population. The knowledge of the morphology of seeds and seedlings is useful in understanding the development of native species, being fundamental in the study of germination in species identification in the juvenile stage, the interpretation of tests of germination and differentiation of congeners. The study of the initial growth of plants is important for establishing standards of seedlings produced in nurseries. The objective of this work was to obtain information on biometrics seed, seedling morphology and early growth of American ximenia L, Genipa americana L., Ziziphus joazeiro Mart., Talisia esculenta Raldk and Crataeva tapia L. The experiments were conducted at the Center for Teaching and Research in Urban Agriculture (NEPAU), Department of Plant Science in CCA / UFC, Fortaleza-CE. Biometrics seeds was performed on a sample of 100 diaspores of each species. To study the morphology of seedlings made up planting 100 seeds in tubes of 288cm Â s filled with vermiculite and humus in the volume ratio 2:1, except Juazeiro whose endocarps previously scarified, were sown in beds tire containing 2 offish 1 humus (v/v). We carried out daily photographic records of germination and seedling establishment process. The initial growth analysis was performed in two environments (full sun and greenhouse) during seven periods in a split plot design with six replications, in a randomized design, except for jujube plum mad and whose evaluations were performed only at home vegetation. The length values observed in âameixa-bravaâ, âgenipapoâ, âjuazeiroâ, âpitombaâ and âtrapiÃâ were 14.98; 9.64; 8.74; 18.25 and 7.72 mm respectively. âAmeixa-bravaâ and âpitombaâ presented hypogeal cryptocotyledonary germination, while the genipap âjuazeiroâ and âtrapiÃâ and were characterized as phanerocotylar epigeal. TrapiÃ plants kept in the greenhouse showed better development. Seedlings âgenipapoâ and âpitombaâ full sunlight exhibited greater development. The pattern of seedling plum mad at 109 days: 12.13 cm, 19.02 cm root length, 3.52 mm diameters and 7.1 leaves. The âjuazeiroâ seedlings with 138 days exhibited the following pattern: height - 41.33 cm; root length - 37.84; stem diameter - 4.13 mm and number of leaves - 43.05. As frutas nativas brasileiras estÃo entre as mais saborosas e nutritivas do mundo, sendo conhecidas apenas pela populaÃÃo local. O conhecimento da morfologia de sementes e plÃntulas Ã Ãtil na compreensÃo do desenvolvimento das espÃcies nativas, sendo fundamentais no estudo da germinaÃÃo, na identificaÃÃo de espÃcies na fase juvenil, na interpretaÃÃo dos testes de germinaÃÃo e diferenciaÃÃo de espÃcies congÃneres. O estudo do crescimento inicial das plantas Ã importante para o estabelecimento de padrÃes de qualidade de mudas produzidas nos viveiros. Objetivou-se neste trabalho obter informaÃÃes sobre biometria de sementes, morfologia de plÃntulas e crescimento inicial de ameixa-brava (Ximenia americana L.), jenipapo (Genipa americana L.), juazeiro (Ziziphus joazeiro Mart.), pitomba (Talisia esculenta Raldk) e trapiÃ (Crateva trapia L.). Os experimentos foram desenvolvidos no NÃcleo de Ensino e Pesquisa em Agricultura Urbana (NEPAU), do Departamento em Fitotecnia CCA/UFC, em Fortaleza-CE. A biometria das sementes foi realizada em uma amostra de 100 diÃsporos de cada espÃcie. Para o estudo dos aspectos morfolÃgicos das plÃntulas efetuou-se o plantio de 100 sementes em tubetes de 288cmÂ preenchidos com s vermiculita e hÃmus na proporÃÃo volumÃtrica 2:1, exceto para juazeiro cujos endocarpos, previamente escarificados, foram semeados em canteiros de pneu contendo 2 arisco : 1 hÃmus (v/v). Efetuaram-se registros fotogrÃficos diÃrios do processo de germinaÃÃo e estabelecimento da plÃntula. A anÃlise de crescimento inicial foi realizada em dois ambientes (sol pleno e casa de vegetaÃÃo) durante sete perÃodos num esquema de parcelas subdivididas com seis repetiÃÃes, seguindo um delineamento inteiramente casualizado, exceto para ameixa-brava e juazeiro cujas avaliaÃÃes foram realizadas apenas em casa de vegetaÃÃo. Os valores do comprimento observados em ameixa-brava, jenipapo, juazeiro, pitomba e trapiÃ foram 14,98; 9,64; 8,74; 18,25 e 7,72mm respectivamente. Ameixa-brava e pitomba apresentaram germinaÃÃo hipÃgea criptocotiledonar, enquanto o jenipapo, juazeiro e trapiÃ caracterizaram-se como epÃgea fanerocotiledonar. As plantas de trapiÃ mantidas em casa de vegetaÃÃo apresentaram melhor desenvolvimento. As mudas de jenipapo e pitomba desenvolveram-se mais sob sol pleno. As mudas de ameixa-brava com 109 dias de idade apresentaram 12,13cm de altura, 19,02cm de comprimento de raiz, 3,52mm de diÃmetro do colo e 7,1 folhas. As mudas de juazeiro com 138 dias exibiram o seguinte padrÃo: altura â 41,33cm; comprimento da raiz â 37,84; diÃmetro do colo â 4,13mm e numero de folhas â 43,05.

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Socolowski, Fabio [UNESP]. "Ecologia germinativa, relações alométricas e o efeito da massa das sementes de Tecoma stans L. Juss. ex Kunth (Bignoniaceae) sobre a emergência e desenvolvimento das plântulas." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/100667.

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Made available in DSpace on 2014-06-11T19:30:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-20Bitstream added on 2014-06-13T20:01:15Z : No. of bitstreams: 1 socolowski_f_dr_rcla.pdf: 774673 bytes, checksum: 524e3b5dcb3693c8da59453eb583ea90 (MD5) Este estudo teve como objetivo avaliar a relação entre a massa e características morfométricas de frutos e sementes de Tecoma stans, bem como relacionar a massa das sementes a suas características morfológicas, utilizando paquímetro e imagens de raios X, e fisiológicas, através da germinação, emergência e desenvolvimento inicial de suas plântulas, sob duas condições de luminosidade . a pleno sol e sombra. Além disso, também foram avaliados os efeitos de diferentes condições de temperatura e luz constantes, em laboratório, e em ambiente natural no sol e na sombra na germinação e emergência das plântulas. A massa dos frutos apresentou relações lineares significativas e positivas com suas características morfológicas e de produção de sementes. As relações entre a massa das sementes e suas características morfológicas foram positivas e significativas, porém na forma de uma função potência, sendo esta relação mais evidente com a largura do embrião. A massa das sementes também esteve relacionada a determinadas anomalias do desenvolvimento embrionário, observadas nas imagens de raios X. A germinação, a emergência e o desenvolvimento inicial das plântulas foram significativamente afetados pela massa das sementes, porém somente durante os três primeiros meses de desenvolvimento no ambiente de sol. A temperatura apresentou efeito na germinação e suas sementes germinaram tanto na luz quanto no escuro, contudo a emergência e sobrevivência das plântulas no ambiente de sol foi superior em relação ao observado na sombra. This study had the objective to evaluate the relationship between the mass and the morphometric characteristics of Tecoma stans fruits and seeds, as well as to relate the seed mass with its morphometric characteristics, utilizing caliper and X-ray images, and physiological characteristics, thought germination, emergency and seedlings initial development, under two conditions of light - at the sun and shade. More than, also were evaluated the effects of different conditions of constant temperature and light, under laboratory, and natural environment under sun and shade in the germination and emergency of the seedlings. The fruit mass presented positive, significative linear relationship with his morphological characteristics and with its seed production characteristics. The relationship between seed mass and its morphological characteristics were positive and significative, nevertheless with the model (shape) of power function, being the relationship more clear with the embryo width. The seed mass also was related to determinate anomalies of the embryo development that could be observed in the X-ray images. The germination, the seedling emergence and the initial seedling development were significative affected by seed mass, but only in the firth three months of development at the sun environment. The temperature affected Tecoma stans seed germination in both light and darkness environment, however the seedlings emergency and survival was greater at the sun environment than shade.

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Johansson, Veronika A. "Recruitment ecology and fungal interactions in mycoheterotrophic Ericaceae." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-109160.

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There are generally two contrasting alternatives to what limits recruitment in plants, namely the availability of seeds (seed limitation) or the quality or quantity of suitable sites (microsite limitation). Dust seeds, the smallest existing seeds, lack or have minimal nutrient reserves. During germination and initial development they consequently parasitize on mycorrhizal fungi. This is called mycoheterotrophy, and can vary in degree of fungal dependency in adult plants from full, partial or initial mycoheterotrophy. The aim of this thesis was to investigate the recruitment ecology of mycoheterotrophic Ericaceae (tribe Pyroleae) species with dust seeds, and to determine what limits their recruitment. The investigated species were: Chimaphila umbellata, Moneses uniflora, Orthilia secunda, Pyrola chlorantha, P. minor and P. rotundifolia. This aim was achieved by combining field experiments (seed sowing) with isotope analysis and fungal host pyrosequencing. Results provide evidence that the species in Pyroleae are heterogeneous, not only with regard to their degree of mycoheterotrophy, but also concerning germination and early seedling development. A combination of microsite and seed limitation is thus likely to be of importance for all studied species, but the relative importance of these limitations varies among species. Despite having adaptations for wind dispersal the majority of the seeds were deposited in close vicinity of the seed source. But with high seed production at least some seeds should be able to disperse long-distance. Seedlings of all studied species were found to associate with a wide range of ectomycorrhizal fungi, at least during their initial developmental stages. There seems to be a tendency for host narrowing in some Pyroleae species, but not as strict as the host specialization seen in fully mycoheterotrophic Monotropa hypopitys, supporting the hypothesis of geographical and developmental host shifts. At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.

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Silva, Tatiana Maria da. "Biometria de sementes, morfologia de plântulas e crescimento inicial de cinco espécies frutíferas que ocorrem no Nordeste brasileiro." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/19168.

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SILVA, Tatiana Maria da. Biometria de sementes, morfologia de plântulas e crescimento inicial de cinco espécies frutíferas que ocorrem no Nordeste brasileiro. 2014. 102 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Fitotecnia, Programa de Pós-Graduação em Agronomia / Fitotecnia, Fortaleza-CE, 2014 Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-19T12:05:58Z No. of bitstreams: 1 2014_dis_tmsilva.pdf: 2397961 bytes, checksum: f18fdab2cce9fe3c580e3103454269f3 (MD5) Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-19T12:06:16Z (GMT) No. of bitstreams: 1 2014_dis_tmsilva.pdf: 2397961 bytes, checksum: f18fdab2cce9fe3c580e3103454269f3 (MD5) Made available in DSpace on 2016-08-19T12:06:16Z (GMT). No. of bitstreams: 1 2014_dis_tmsilva.pdf: 2397961 bytes, checksum: f18fdab2cce9fe3c580e3103454269f3 (MD5) Previous issue date: 2014 Brazilian native fruits are among the most tasty and nutritious in the world, being known only by the local population. The knowledge of the morphology of seeds and seedlings is useful in understanding the development of native species, being fundamental in the study of germination in species identification in the juvenile stage, the interpretation of tests of germination and differentiation of congeners. The study of the initial growth of plants is important for establishing standards of seedlings produced in nurseries. The objective of this work was to obtain information on biometrics seed, seedling morphology and early growth of American ximenia L, Genipa americana L., Ziziphus joazeiro Mart., Talisia esculenta Raldk and Crataeva tapia L. The experiments were conducted at the Center for Teaching and Research in Urban Agriculture (NEPAU), Department of Plant Science in CCA / UFC, Fortaleza-CE. Biometrics seeds was performed on a sample of 100 diaspores of each species. To study the morphology of seedlings made up planting 100 seeds in tubes of 288cm ³ s filled with vermiculite and humus in the volume ratio 2:1, except Juazeiro whose endocarps previously scarified, were sown in beds tire containing 2 offish 1 humus (v/v). We carried out daily photographic records of germination and seedling establishment process. The initial growth analysis was performed in two environments (full sun and greenhouse) during seven periods in a split plot design with six replications, in a randomized design, except for jujube plum mad and whose evaluations were performed only at home vegetation. The length values observed in ‘ameixa-brava’, ‘genipapo’, ‘juazeiro’, ‘pitomba’ and ‘trapiá’ were 14.98; 9.64; 8.74; 18.25 and 7.72 mm respectively. ‘Ameixa-brava’ and ‘pitomba’ presented hypogeal cryptocotyledonary germination, while the genipap ‘juazeiro’ and ‘trapiá’ and were characterized as phanerocotylar epigeal. Trapiá plants kept in the greenhouse showed better development. Seedlings ‘genipapo’ and ‘pitomba’ full sunlight exhibited greater development. The pattern of seedling plum mad at 109 days: 12.13 cm, 19.02 cm root length, 3.52 mm diameters and 7.1 leaves. The ‘juazeiro’ seedlings with 138 days exhibited the following pattern: height - 41.33 cm; root length - 37.84; stem diameter - 4.13 mm and number of leaves - 43.05. As frutas nativas brasileiras estão entre as mais saborosas e nutritivas do mundo, sendo conhecidas apenas pela população local. O conhecimento da morfologia de sementes e plântulas é útil na compreensão do desenvolvimento das espécies nativas, sendo fundamentais no estudo da germinação, na identificação de espécies na fase juvenil, na interpretação dos testes de germinação e diferenciação de espécies congêneres. O estudo do crescimento inicial das plantas é importante para o estabelecimento de padrões de qualidade de mudas produzidas nos viveiros. Objetivou-se neste trabalho obter informações sobre biometria de sementes, morfologia de plântulas e crescimento inicial de ameixa-brava (Ximenia americana L.), jenipapo (Genipa americana L.), juazeiro (Ziziphus joazeiro Mart.), pitomba (Talisia esculenta Raldk) e trapiá (Crateva trapia L.). Os experimentos foram desenvolvidos no Núcleo de Ensino e Pesquisa em Agricultura Urbana (NEPAU), do Departamento em Fitotecnia CCA/UFC, em Fortaleza-CE. A biometria das sementes foi realizada em uma amostra de 100 diásporos de cada espécie. Para o estudo dos aspectos morfológicos das plântulas efetuou-se o plantio de 100 sementes em tubetes de 288cm³ preenchidos com s vermiculita e húmus na proporção volumétrica 2:1, exceto para juazeiro cujos endocarpos, previamente escarificados, foram semeados em canteiros de pneu contendo 2 arisco : 1 húmus (v/v). Efetuaram-se registros fotográficos diários do processo de germinação e estabelecimento da plântula. A análise de crescimento inicial foi realizada em dois ambientes (sol pleno e casa de vegetação) durante sete períodos num esquema de parcelas subdivididas com seis repetições, seguindo um delineamento inteiramente casualizado, exceto para ameixa-brava e juazeiro cujas avaliações foram realizadas apenas em casa de vegetação. Os valores do comprimento observados em ameixa-brava, jenipapo, juazeiro, pitomba e trapiá foram 14,98; 9,64; 8,74; 18,25 e 7,72mm respectivamente. Ameixa-brava e pitomba apresentaram germinação hipógea criptocotiledonar, enquanto o jenipapo, juazeiro e trapiá caracterizaram-se como epígea fanerocotiledonar. As plantas de trapiá mantidas em casa de vegetação apresentaram melhor desenvolvimento. As mudas de jenipapo e pitomba desenvolveram-se mais sob sol pleno. As mudas de ameixa-brava com 109 dias de idade apresentaram 12,13cm de altura, 19,02cm de comprimento de raiz, 3,52mm de diâmetro do colo e 7,1 folhas. As mudas de juazeiro com 138 dias exibiram o seguinte padrão: altura – 41,33cm; comprimento da raiz – 37,84; diâmetro do colo – 4,13mm e numero de folhas – 43,05.

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Leal, Cintia Müller. "Superação de dormência e produção de mudas de Anacauíta (Schinus molle L.)." Universidade Federal de Pelotas, 2015. http://repositorio.ufpel.edu.br:8080/handle/prefix/3299.

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Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-04-04T13:22:16Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_cintia_muller_leal.pdf: 2650724 bytes, checksum: 0735a2bb9f056999c0b6a14b82b893b4 (MD5) Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-07T18:52:23Z (GMT) No. of bitstreams: 2 dissertacao_cintia_muller_leal.pdf: 2650724 bytes, checksum: 0735a2bb9f056999c0b6a14b82b893b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-07T18:59:09Z (GMT) No. of bitstreams: 2 dissertacao_cintia_muller_leal.pdf: 2650724 bytes, checksum: 0735a2bb9f056999c0b6a14b82b893b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2017-04-07T18:59:23Z (GMT). No. of bitstreams: 2 dissertacao_cintia_muller_leal.pdf: 2650724 bytes, checksum: 0735a2bb9f056999c0b6a14b82b893b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-12-07 Sem bolsa Anacauíta (Schinus molle L.) é uma espécie arbórea de ocorrência nativa no Rio Grande do Sul, pioneira de pequeno porte, com importância ecológica, bioquímica e farmacológica, contudo suas sementes apresentam dormência, fato que dificulta a produção de mudas em escala comercial. Este trabalho objetivou avaliar métodos de superação de dormência das sementes de S. molle de um lote com 15 meses de armazenamento em câmara fria seca e germinação inicial de 5% quando submetidas a tratamento para superação de dormência com ácido sulfúrico por 160 minutos, utilizando diferentes tempos de escarificação mecânica (150, 300, 450 e 600 segundos) em escarificador elétrico equipado com lixa grão 80. O tratamento de 150 segundos de escarificação mecânica proporcionou maior percentual de germinação (61%), menor número de sementes mortas e plântulas anormais, maior massa seca e comprimento de plântulas aos sete dias, maior embebição e maior índice de velocidade de emergência (2,28). Para a produção de mudas desta espécie foram testados dois volumes de tubetes (100 e 175 mL) e quatro níveis de adubação com fertilizante de liberação controlada (FLC) Osmocote Plus, em um experimento fatorial 2 x 4. Os níveis de adubação com FLC foram zero, quatro, oito e doze gramas por litro de substrato. Os resultados quanto aos parâmetros de crescimento e qualidade de mudas, onde foram avaliados altura, diâmetro do coleto, número de folhas, relação altura/diâmetro do coleto, massa seca da raiz, massa seca da parte aérea, massa seca total, relação massa seca da parte aérea e massa seca da raiz, volume de raiz, índice de qualidade de Dickson, índice de clorofila, teor de clorofila a, clorofila b e carotenoides ao longo de 120 dias após a emergência das plântulas, revelou que o tubete de 175 mL e a dosagem de oito gramas de FLC por litro de substrato foi superior aos demais tratamentos por produzir mudas de anacauíta de alta qualidade. Anacauita (Schinus molle L.) is arborea, native species in a Rio Grande do Sul small pioneer with ecological, biochemical and pharmacological importance, but its seeds present dormancy , a fact that hinders the production of seedlings on a commercial scale. This study aimed at evaluating methods of overcoming seed dormancy of S. molle of a batch of 15 months of storage in dry cold chamber and 5% germination when undergoing treatment to overcome dormancy with sulfuric acid for 160 minutes, using different times mechanical scarification (150, 300, 450 and 600 seconds) in electric scarifier equipped with 80 grit sandpaper. Treatment of 150 seconds of mechanical scarification showed higher germination percentage (61%), fewer dead seeds and abnormal seedlings, imbibition largest and most emergency velocity index (2.28). For the production of seedlings of this species were tested two volumes of tubes (100 and 175 mL) and four levels of fertilizer controlled release fertilizer (CRF) Osmocote Plus in 2 x 4 factorial experiment. Nutrient levels were CRF zero, four, eight and twelve grams per liter of substrate. The results regarding the growth parameters and quality seedlings, which were assessed height, stem diameter, number of leaves, height / stem diameter, root dry mass, dry mass of shoots, total dry matter, dry weight ratio of shoot and root dry mass, root volume, Dickson quality index, chlorophyll index, chlorophyll content a, chlorophyll b and carotenoids over 120 days after seedling emergence, revealed that the plastic tube 175 ml and the dose of CRF eight grams per liter substrate was superior to the other treatments for producing seedlings of high quality anacauita.

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Silva, Shelka Alcântara da. "Germinação e morfoanatomia do desenvolvimento pós-seminal de espécies de Vellozia Vand. de campos rupestres brasileiros." Universidade Federal de Uberlândia, 2013. https://repositorio.ufu.br/handle/123456789/12434.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Velloziaceae is a relatively small family from Pandanales, including approximately 250 species that are very common in the brazilians campos rupestres . The Velloziaceae have a high degree of endemism, and some species are threatened with extinction. Several species of Velloziaceae have potential ornamental use, both for plant architecture as the foliage, or due to the beauty of their flowers. However, few studies investigate the germinative behavior and the post-seminal development of these species. In order to contribute with the knowledge of the germination and post-seminal development of Velloziaceae were analyzed seeds of twelve species of Vellozia Vand. from Minas Gerais and Goiás campos rupestres . The seeds were sown in Emanueli chambers and the experiments were installed in germination chamber under controlled light and temperature. The data about germinative behavior and post-seminal development morphology and anatomy were obtained using the usual techniques for each case. The seeds of the studied species are small, preferentially photoblastic and most of them exhibit high germinability (G ≥ 60%) and high values of mean germination rates (0,06 ≤ v ≤ 0,21 day-1). The coefficient of variation of the germination time and the measurements of uncertainty and synchrony revealed that the species can be separated in two groups: in the first group are the species exhibiting heterogeneous and spread germination through the time and in the second group were coupled the species exhibiting homogenous germination more concentrated over time. The photoblastism and fast germination, yet spread in time, suggest relative dormancy, which is common in seeds from species adapted to adverse environmental conditions and indicate that the seeds of these species can form seed banks. The seeds are small and bitegumented. The embryo is small and exhibits a single vascular bundle in the cotyledon. Germination begins with the protrusion of the cotyledon s base and radicle and the seedling is criptocotylar. The primary root is persistent and forms lateral roots. Eophyll and methaphyll are similar. Seedling vascularization is reduced. The Vellozia exhibited similar morphological and anatomical characters during the post-seminal development, which reinforces the genera identity. As Velloziaceae, uma família relativamente pequena da ordem Pandanales, com aproximadamente 250 espécies, são frequentemente encontradas nos campos rupestres do Brasil, onde apresentam alto grau de endemismo, bem como, algumas espécies encontramse ameaçadas de extinção. Várias espécies de Velloziaceae apresentam potencial ornamental, tanto pela folhagem, quanto pela beleza das flores. No entanto, poucos são os estudos que investigam o comportamento germinativo e o desenvolvimento pós-seminal dessas espécies. Visando contribuir com esses estudos, sementes de doze espécies de Vellozia Vand. foram coletadas nos campos rupestres de Minas Gerais e Goiás. As sementes foram semeadas em Câmaras de Emanueli e os experimentos instalados em câmara de germinação, sob luz e temperatura controladas. Os dados sobre o comportamento germinativo e a morfoanatomia foram obtidos utilizando-se as técnicas usuais para cada caso. As sementes das espécies estudadas são preferencialmente fotoblásticas e a maioria delas apresentou alta germinabilidade (G ≥ 60%) e velocidade média de germinação alta (0,06 ≤ v ≤ 0,21 dia-1). O coeficiente de variação do tempo de germinação, as medidas de incerteza e de sincronia revelaram que essas espécies podem ser agrupadas em dois grupos: no primeiro, aquelas que apresentam germinação heterogênea e espalhada no tempo e, no segundo, as que exibem germinação homogênea e mais concentrada no tempo. O fotoblastismo e a germinação rápida, porém espalhada no tempo, sugerem dormência relativa, que é comum para sementes de espécies adaptadas às condições ambientais adversas e indica o potencial dessas sementes para formar banco de sementes. As sementes de Vellozia são pequenas e bitegumentadas. O embrião é pequeno e exibe um único feixe vascular no cotilédone. A germinação inicia-se com a protrusão da base do cotilédone e da radícula e a plântula é criptocotiledonar. A vascularização da plântula é reduzida. A raiz primária é persistente e forma raízes laterais. Eofilo e metafilo são semelhantes. As Vellozia estudadas apresentaram caracteres morfoanatômicos semelhantes durante o desenvolvimento pós-seminal, o que reforça a identidade do gênero. Mestre em Biologia Vegetal

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29

Nielsen, Michele Erin. "Seed and seedling dynamics of the seagrass, Zostera japonica Aschers. and Graebn. and the influence of Zostera marina L." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30172.

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The seagrass Zostera japonica Aschers. and Graebn. occurs as pure populations and in mixture with Zostera marina L. along the intertidal regions of southwest British Columbia. At the Roberts Bank study area seed and seedling dynamics were studied in three vegetation zones: a landward monospecific zone of Z. japonica, a zone of co-existing Z. japonica and Z. marina, and a seaward monospecific zone of Z. marina. Many more seeds were produced than were found in the sediment, and even fewer germinated. Zostera japonica seeds were most abundant in the seed bank in the upper zones where there is high Z. japonica density. Even though seeds remained in the water column for up to two months, very few seeds dispersed into the lower zone populated by Z. marina. thus limiting Z. japonica's colonization of the lower zones. It is unclear what limits the dispersal of Z. japonica seeds. Of the seeds that were incorporated into the sediment few germinated (5% or less). When seeds were planted in buckets placed into the sediment, with and without Z. marina, Z. japonica was able to germinate, grow, and reproduce in one year throughout the study area. Seedlings that emerged earliest (in April) either did not establish or did not survive as long as those seedlings that emerged later in May and June. Seedlings were often found uprooted, floating in the water. The rim of the buckets and the presence of Z. marina shoots appeared to protect the Z. japonica seedlings, preventing uprooting, but the results were not conclusive. Once seedlings became established, they spread vegetatively at a rapid rate and can persist throughout the winter, either as reduced shoots or as overwintering rhizomes. These overwintering plants contribute greatly to the following year's population. Science, Faculty of Botany, Department of Graduate

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30

Hoak, Jessica. "Tracking Tobacco Mosaic Virus Infection from Infected Seeds to Seedlings Confirms Seed Transmission in Tobacco (Nicotiana tabacum L.)." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/101702.

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The Tobacco mosaic virus (TMV) is a positive sense single stranded RNA virus and is found across the world. TMV can impact the overall yield and quality of the crop resulting in an economic loss. Plants that are infected with TMV show a variety of symptoms such as mosaic pattern, mottling, necrotic lesions and stunted growth. Historically, TMV has caused controversy on whether this economically significant virus is seedborne or seed transmitted. The objective of this study is to track TMV infection from infected seeds to seedlings to determine the percentage of seed transmission. This experiment used three pods from three different TMV infected cultivar K 326 flue-cured tobacco plants. Seeds from each pod were germinated in a growth chamber for approximately ten days. Samples were separated into seed coat, root and leaves after germination. Total RNA was extracted from each part and synthesized into cDNA for analysis. A quantitative real-time PCR (RT-qPCR) assay was used to determine TMV concentration of each sample. Endpoint RT-PCR was used to determine a conservative threshold value from the RT-qPCR results. These results demonstrated that TMV influenced percent germination with a range from 94% to 50%. Seed coats had a significantly higher virus titer concentration (P < 0.05) when compared to the roots and leaves. Statistical analysis revealed highly significant (P < 0.0001) differences among pods for virus titer and there is a highly significant plant by pod interaction (P < 0.0001). Endpoint RT-PCR confirmed TMV infection in leaves, roots and seed coats. Percent infection in leaves ranged from 2% to 24% and percent infection for roots ranged from 8% to 40%. Results demonstrate that TMV is seed transmitted in flue-cured tobacco. Master of Science

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31

Lange, Peter R. "Arabidopsis thaliana mutants impaired in storage fatty acid breakdown." Thesis, University of York, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369327.

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Bultitude, J. M. "The survival of seeds and seedlings on colliery spoil." Thesis, University of York, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373312.

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33

Mustart, Penny. "Seed and seedling ecology of four Agulhas Proteaceae." Doctoral thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/9671.

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Includes bibliographical references Serotinous (canopy-stored seed) Proteaceae, Protea obtusifolia and Leucadendron meridianum occur on shallow, alkaline soils overlying limestone, and P.susannae and L.coniferum on adjacent, deep, weakly acidic sands, in fire-prone fynbos. Seed reciprocal transplants were used to test whether regeneration niche requirements were determinants of adult distributions. There were no germination niche differences, but limestone species showed greater seedling mortality on the transplanted colluvial sands than limestone. There were also greater relative growth rates of seedlings on their own soil than counterparts on transplanted soil.

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34

Schutte, Brian J. "Biology and ecology of Ambrosia Trifida L. seedling emergence." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1181937971.

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Camara, Armando Tadeo Rodriguez da [UNESP]. "Armazenamento de sementes pré-germinadas de Inga vera Willd." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/99770.

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Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-09Bitstream added on 2014-06-13T19:39:48Z : No. of bitstreams: 1 camara_atr_me_botfca.pdf: 536810 bytes, checksum: 57f5286522d61f84e18be56157805a7d (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Sementes recalcitrantes sempre apresentam dificuldades em seu armazenamento, tornandose um problema para produtores de mudas que muitas vezes não têm como realizar a semeadura logo após a colheita das sementes ou necessitam produzir mudas em diferentes épocas do ano, além de dificultar a conservação de germoplasma. As sementes de ingá, depois de colhidas, perdem sua viabilidade rapidamente, geralmente não ultrapassando 15 dias. As espécies de sementes recalcitrantes normalmente não utilizam bancos de sementes como estratégia de regeneração em condições naturais. Observações ecológicas têm mostrado que é mais comum sua regeneração natural ser por meio de bancos de plântulas. O objetivo do trabalho foi avaliar o armazenamento de sementes pré-germinadas de Inga vera Willd., provenientes de frutos em dois estádios diferentes de maturação, em três condições diferentes de umidade de substrato e em baixa temperatura. Os frutos de Inga vera Willd. colhidos foram separados em duas categorias, de acordo com sua coloração de casca, entre verdes e maduros. Após seu beneficiamento, as sementes foram prégerminadas e armazenadas em substrato sem adição de água (testemunha), com 30 e 60% de umidade sob baixa temperatura (10°C), por um ano. O armazenamento feito a 30 e 60% de umidade mostrou-se com melhor eficiência, tanto para plântulas provenientes de frutos verdes, como as de frutos maduros. Entre os dois tipos de frutos, observou-se que as plântulas obtidas de vagem verde, obtiveram melhor desempenho sob as condições de armazenamento, em relação àquelas obtidas de vagem madura. Podem ser armazenadas por até quatro meses, mantendo 50% de sobrevivência das plântulas do lote, quando o armazenamento é feito sob baixa temperatura (10 ± 5°C) e em substrato com 30 e 60% de umidade. Após um período de armazenamento... Recalcitrant seeds always present difficulties for storage procedures, becoming a problem for seedling producers that often have no choice to sow them immediately after seed harvest or when they need to produce seedlings through different times by the year. Inga seeds, once harvested, lose quickly their viability, often not exceeding a period of 15 days. Species of recalcitrant seeds do not use seed banks as regeneration strategy into the natural environment. Ecological observations have shown that is common occur their natural regeneration through seedling banks. The objective of this work was to evaluate pregerminated seed storage of Inga vera Willd. from two fruit maturation stages, under different conditions of substrate humidity, and under low temperature. The collected fruits of I. vera 9were splited into two types, according to their color, between unripe and ripe. After the processing of those seeds, they were pre-germinated on substrate and stored in substrate with no water addition (control), 30, and 60% humidity under low temperature (10°C) for a year. The storage made under 30 and 60% humidity showed to be the best for both, seedlings from unripe and ripe fruits. Between two types of fruits, we observed that the seedlings from unripe fruits, presented better performance under storage conditions, when compared to those obtained from mature fruits. They can be stored for until four months, with 50% of seedling survivals when stored under low temperature (10 ± 5°C) and with 30 and 60% of substrate humidity. After a year of seedling storage it was possible to get until 10% of survival... (Complete abstract click electronic access below)

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36

Lönnberg, Karin. "Effects of seed size and habitat on recruitment patterns in grassland and forest plants." Doctoral thesis, Stockholms universitet, Botaniska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-82384.

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A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. Small seeds, however, are numerous and small-seeded species are therefore more fecund. Moreover, a pattern with small-seeded species being associated with open habitats and large-seeded species being associated with closed habitats has been reported in the literature. In this thesis I assess effects of seed size on recruitment, and how relationships between seed size and recruitment may relate to habitat conditions. Seed sowing experiments were performed in the field to assess inter- and intra-specific relationships between seed size and recruitment in open and closed habitats (Paper I and II). Seed removal experiments were performed in the field to assess what effects seed predation may have on a relationship between seed size and recruitment (Paper III). A garden experiment was performed based on contests between larger-seeded and smaller-seeded species, in order to examine different models on co-existence of multiple seed size strategies. The results showed that there was a weak positive relationship between seed size and recruitment in the field, and that this relationship was only weakly and inconclusively related to habitat (Paper I and II). Seed removal was negatively related to seed size in closed habitats and unrelated to seed size in open habitats (Paper III). This indicates that any positive relationship between seed size and recruitment may be an effect of higher seed removal in small-seeded species. However, when grown under controlled conditions in a garden experiment, there was a clear advantage of larger-seeded species over smaller-seeded species (Paper IV). This advantage was unaffected by seed density, indicating that there was no competitive advantage of the larger-seeded species. Instead, indirect evidence suggests that larger-seeded species exhibit higher tolerance to stress. At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Accepted.

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Sinclair, John. "Crusting, soil strength and seedling emergence in Botswana." Thesis, University of Aberdeen, 1985. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU363198.

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This thesis gives the results of an investigation of the strengths and particularly the crust forming potential of arable soils from Botswana and the relationship to seedling emergence of sorghum, the most important crop in Botswana and one that because of its small seed weight (about 2 0 mg) can fail to emerge through a hard soil crust. A review of the literature suggested that the soil factors which had to be considered were dispersibility of clay and factors which affect this, and the bulk density of the soils. Soils which are found in many tropical and sub-tropical regions, with low organic matter and inactive clays can set hard after a simple wetting and drying cycle. In these soils, the strength is very strongly dependent on the water content, showing a hyperbolic or exponential relationship-, and the strengths when dry may be very greatly increased by remoulding the wet soil. The crust strength required to prevent seedling emergence varies with the size of the seedling and for cotton (seed weight about 80 mg), 1-3 MPa penetration resistance measured with a penetrometer is sufficient to prevent emergence. Seedlings exert a total force proportional to their number. In the experimental programme, seedlings' forces were measured, seedling emergence observed in a field experiment under crusting conditions, and the strength characteristics of a group of soils, representative of arable soils in Botswana, studied. A sorghum seedling was found to exert a maximum force of about 1 N or dividing by the area of the plumule, a pressure of about 0,5 MPa. The field experiment showed that much better emergence was obtained from planting 15 seeds together than from planting 4 seeds together when a crust formed after planting. A study of 32 soils, most of them sand to sandy loam in texture but with a few clays and hydroirorphic soils, from arable areas in Botswana showed the sandy to sandy loam soils to have high bulk densities ( 1,45-1 ,75 Mg/m3) and extremely low organic carbon contents (0,12-0,85 g/100g). The bulk densities of all the soils were inversely related to the organic carbon content and this was itself related to the clay content of the soils. The bulk densities of the sands were dependent on the grading of the sand fraction. Many of the soils were sensitive to remoulding in the Emerson test and the sands to loany sands had 0,4-1,0 g/100 g water dispersible clay. Measurements of tensile strength on air-dry samples showed that all the soils, except for one sand, set hard after a wetting and drying cycle, giving for vacuum wet samples indirect tensile strengths 1,0-14,4 kPa. For the sands to sandy loams this strength was related to the water dispersible clay content. Samples wet at atmospheric pressure were weaker than the vacuum wet samples, the reduction in strength was related to the air porosity of the non-vacuum wet soils prior to drying. Remoulding the soils prior to drying them increased the strength by a factor of up to 50 times, giving strengths from 4 kPa to 600 kPa. The strength after remoulding was dependent on the Emerson index. Compacting the soils increased their strength greatly and to an extent that agreed with the hypothesis that the strength obtained was proportional to the area of contact between the particles. Experiments on penetration resistance at a range of water contents were performed on a few soils. A hyperbolic relationship between water content and penetration resistance of the surface soil was found for sand to sandy loam soils, with the maximum resistance of dry soils above 2 MPa. The penetration resistance of the sandy loam soil was Increased three times by disturbing it when wet. Sprinkler wetting the sieved soils was not found to affect the penetration resistance by a large amount compared and other methods of welting. Penetration resistance was measured on air-dry samples of most of the main group of soils following varying degrees of wetting with a rainfall simulator. The clays and hydromorphic soils gave very low values of penetration resistance under these conditions, showing that at organic carbon contents of about 1% and clay contents from 20 to 30%, the decreased bulk density and tendency to form aggregates' on drying overcame the tendency to set hard. The mean values for the sands to sandy loams were from 1 to 6 MPa so all these soils could offer significant resistance to a sorghum seedling. The penetration resistance of the sands and loam/ sands depended on their bulk densities and water dispersible clay contents, while the penetration resistance of the sandy loams depended only on the water dispersible clay content.

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McElhannon, Laura Michelle Waters Luther. "Enhancement of seed germination and seedling growth of Lenten rose." Auburn, Ala., 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Horticulture/Thesis/Moore_Laura_47.pdf.

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Salazar, Ana. "Seed Dynamics and Seedling Establishment of Woody Species in the Tropical Savannas of Central Brazil (Cerrado)." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/371.

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Studies of seed dynamics and seedling establishment at the community level in savanna ecosystems are scant, particularly in the tropical savannas of Central Brazil. The Brazilian savannas (cerrado) have the largest diversity of plant species among Neotropical savannas. Cerrado vegetation exhibits consistent changes in tree density and tree size along shallow topographic gradients. Vegetation types differ from closed savannas with high tree density, and a nearly continuous canopy cover in the uppermost portions, to open savannas with scattered short trees in the low portions of the topographic gradients. Whether or not dynamics of seeds and seedlings of woody species are consistent with variations in tree density and tree canopy cover across the cerrado landscape has not been determined, but could potentially influence such spatial patterns of tree density and canopy cover. The main objective of this study was to evaluate seed dynamics (i.e., seed rain, soil seed banks, and seed characteristics) and seedling establishment of woody species in three major cerrado vegetation types (closed, intermediate and open savannas) which differ in tree canopy cover and tree height. These vegetation types are located along topographic gradients of approximately 30 m in elevation and 1000 m in length. I conducted field work from June 2005 to August 2008 at the Instituto Brasileiro de Geografia e Estatística (IBGE) reserve, a field experimental station located 35 Km south of Brasilia, Brazil (15˚ 56' S, 47˚ 63' W, altitude 1100 m). I established permanent plots in each of the three vegetation types to assess seed rain, seed limitation, seed predation, and seed removal. I also quantified density and composition of the soil seed bank in each vegetation type and studied seed characteristics (i.e., kind of dormancy, moisture content, longevity) of 14 common cerrado woody species. In the field, I quantified establishment of woody seedlings in fire-protected savannas as well as in accidentally burned and frequently burned savannas. In the greenhouse I performed experiments to evaluate the effect of litter cover and light level on seedling emergence of 9 common cerrado woody species. Finally, I evaluated the effect of pulses of heat on seed germination of 5 common cerrado woody species under controlled conditions. The overall results of this study show that regardless of tree canopy cover, cerrado vegetation types are limited in seeds and seedlings of woody species, but these limitations are higher in open than in closed savannas. Most woody species do not form persistent soil seed banks along cerrado vegetation types because their seeds are short-lived, predated and quickly removed from the ground. In addition, dispersal season and dormancy appear to control timing of germination at the onset of the rainy season to ensure survival of seedlings in the field. In the absence of fire, establishment of woody seedlings is higher in closed than in open savannas because canopy cover mitigates the stressful environmental conditions of open savannas and thus facilitates establishment of woody seedlings. As a result, closed savannas are likely to maintain higher density of woody elements over time than open savannas. In burned savannas, however, species composition of woody and herbaceous seedlings is significantly affected because establishment of seedlings of woody and herbaceous species decreases but vegetative reproduction increases. This dissertation study indicates that interactions of early life-history stages of woody species with environmental and disturbance factors appear to play a more significant role in maintaining woody cover variations along cerrado topographic gradients than previously recognized.

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ALMEIDA, Camilo de Lellis de Sousa. "Uso de thichoderma spp. na emergência de plântulas de gravioleira e produção de mudas em diferentes substratos e ambientes." Universidade Federal de Campina Grande, 2017. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/750.

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Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-21T12:47:22Z No. of bitstreams: 1 CAMILO DE LELLIS DE SOUSA ALMEIDA - DISSERTAÇÃO PPGHT - 2017.pdf: 2546909 bytes, checksum: 9a17a6c6552ab2c6353bb8690f5b1fd3 (MD5) Made available in DSpace on 2018-05-21T12:47:23Z (GMT). No. of bitstreams: 1 CAMILO DE LELLIS DE SOUSA ALMEIDA - DISSERTAÇÃO PPGHT - 2017.pdf: 2546909 bytes, checksum: 9a17a6c6552ab2c6353bb8690f5b1fd3 (MD5) Previous issue date: 2017-11-24 A gravioleira é uma frutífera de grande importância para região Nordeste brasileira. Atualmente a cultura encontra-se em expansão, tendo a necessidade de estudos que visem aumentar a disponibilidade da planta para formação de novos pomares. Assim, este trabalho teve como objetivo avaliar o efeito de isolados de Trichoderma spp. no crescimento inicial de plântulas de gravioleira, bem como estudar a influência de ambientes e diferentes substratos no desenvolvimento de mudas. Os experimentos foram conduzidos nas instalações da Universidade Federal de Campina Grande (UFCG), no Centro de Ciências e Tecnologia Agroalimentar (CCTA), campus Pombal - PB. Para o primeiro experimento, as sementes de graviola cultivar Morada foram provenientes de frutos do pomar comercial localizado no Sítio Gado Brabo, município de Aparecida - PB. As sementes de graviola foram submersas por um período de 24 horas, nos respectivos tratamentos: T1 = Testemunha, sementes submersas em água destilada; T2 = Trichoderma harzianum na concentração de 2x108 UFC; T3 = Trichoderma longibrachiatum na concentração de 2x108 UFC; e T4 = T2 + T3. As características avaliadas foram altura de plântulas, diâmetro do caule, número de folhas, massa seca da parte aérea, massa seca da raiz, massa seca total e índice de qualidade de Dickson. Já para o segundo experimento, também foram utilizadas as sementes da cultivar Morada, semeadas nos substratos constituídos pelas diferentes combinações de esterco bovino, esterco caprino, fibra de coco e basaplant, que variaram de 25 a 50%, combinadas com solo nas proporções de 25, 50 e 100%, de acordo com seus respectivos tratamentos. O experimento foi conduzido em dois ambentes: A1- Viveiro coberto com malha sombrite® 50% e A2 - a ceu aberto. As variáveis analisadas foram: índice de velocidade de emergência, porcentagem de emergência, taxa de assimilação de CO2, transpiração, condutância estomática, concentração interna de CO2, eficiência no uso da água e a eficiência instantânea da carboxilação, aos 60 dias após o semeio. Ao longo do desenvolvimento 60, 80, 100 e 120 dias após o semeio, foram realizadas avaliações para altura de planta, diâmetro do caule e número de folhas. No final do experimento, aos 120 dias, foram realizados o comprimento de raiz, massa seca da parte aérea e raiz, massa seca total e o índice de qualidade de Dickson. Em posse dos dados dos experimentos, conclui-se que o Trichoderma harzianum e Trichoderma 1Orientador(a): Drª. Marinês Pereira Bomfim, UFCG/CCTA longibrachiatum não afetaram a promoção de crescimento de plântulas de gravioleira, nas condições em que o trabalho foi desenvolvido. Já para o segundo experimento, o ambiente viveiro com sombrite® 50% foi o melhor para a formação das mudas, e os tratamentos contendo esterco bovino são mais propícios para a formação das mudas de gravioleira, com destaque para os tratamentos T2 e T5, por apresentarem em suas composições maiores concentrações de solo, proporcionando diminuição nas concentrações de basaplant ou fibra de coco, que são materiais mais caros, sem prejuízos na qualidade de mudas. The soursop is a fruit of great importance for the Brazilian Northeastern region. Currently, the crop is expanding, and studies are needed to increase plant availability for new orchards. Thus, this work aimed to evaluate the effect of Trichoderma spp. in the initial growth of soursop seedlings, as well as to study the influence of environments and different substrates in the development of seedlings. The experiments were conducted at the Federal University of Campina Grande (FUCG), at the Center for Agro-Food Science and Technology (CAST), Pombal-PB campus. For the first experiment, soursop Morada variety seeds were obtained from fruits of the commercial orchard located in the Gado Brabo Farm, in the municipality of Aparecida - PB. The soursop seeds were submerged for a period of 24 hours in the respective treatments: T1 = Test, seeds submerged in distilled water; T2 = Trichoderma harzianum at 2x108 CFU concentration; T3 = Trichoderma longibrachiatum at 2x108 CFU concentration; and T4 = T2 + T3. The evaluated characteristics were seedling height, stem diameter, number of leaves, dry shoot mass, root dry mass, total dry mass and Dickson quality index. Also for the second experiment, the seeds of the Morada variety were also sown on the substrates composed of different combinations of cattle manure, goat manure, coconut fiber and basaplant, which varied from 25 to 50%, combined with soil in proportions of 25, 50 and 100%, according to their respective treatments. The experiment was conducted in two environments: A1- Covered vivarium with sombrite® 50% mesh and A2 - the open sky. The variables analyzed were: emergence speed index, emergency percentage, CO2 assimilation rate, transpiration, stomatal conductance, CO2 internal concentration, water use efficiency and instantaneous carboxylation efficiency at 60 days after sowing. During planting 60, 80, 100 and 120 days after sowing, evaluations were done for plant height, stem diameter and leaf number. At the end of the experiment, at 120 days, the root length, dry shoot and root mass, total dry mass and the Dickson quality index were determined. Based on the data from the experiments, it was concluded that Trichoderma harzianum and Trichoderma longibrachiatum Didn't affect the growth promotion of soursop seedlings under the conditions in which the work was developed. For the second experiment, the vivarium environment with sombrite® 50% was the best for seedling formation, and the treatments containing bovine 1Orientador(a): Drª. Marinês Pereira Bomfim, UFCG/CCTA manure are more favorable for the formation of soursop seedlings, with emphasis on T2 and T5 treatments, for to present higher concentrations of soil in their compositions, providing a reduction in the concentrations of basaplant or coconut fiber, which are more expensive materials, without loss of seed quality.

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Nystrand, Ove. "Post-dispersal predation on conifer seeds and juvenile seedlings in boreal forest /." Umeå : Swedish University of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5345-3.gif.

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42

Camara, Armando Tadeo Rodriguez da 1985. "Armazenamento de sementes pré-germinadas de Inga vera Willd. /." Botucatu : [s.n.], 2011. http://hdl.handle.net/11449/99770.

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Orientador: Edson Seizo Mori Banca: Marcia Balistiero Figliolia Banca: Edvaldo Aparecido Amaral da Silva Resumo: Sementes recalcitrantes sempre apresentam dificuldades em seu armazenamento, tornandose um problema para produtores de mudas que muitas vezes não têm como realizar a semeadura logo após a colheita das sementes ou necessitam produzir mudas em diferentes épocas do ano, além de dificultar a conservação de germoplasma. As sementes de ingá, depois de colhidas, perdem sua viabilidade rapidamente, geralmente não ultrapassando 15 dias. As espécies de sementes recalcitrantes normalmente não utilizam bancos de sementes como estratégia de regeneração em condições naturais. Observações ecológicas têm mostrado que é mais comum sua regeneração natural ser por meio de bancos de plântulas. O objetivo do trabalho foi avaliar o armazenamento de sementes pré-germinadas de Inga vera Willd., provenientes de frutos em dois estádios diferentes de maturação, em três condições diferentes de umidade de substrato e em baixa temperatura. Os frutos de Inga vera Willd. colhidos foram separados em duas categorias, de acordo com sua coloração de casca, entre verdes e maduros. Após seu beneficiamento, as sementes foram prégerminadas e armazenadas em substrato sem adição de água (testemunha), com 30 e 60% de umidade sob baixa temperatura (10°C), por um ano. O armazenamento feito a 30 e 60% de umidade mostrou-se com melhor eficiência, tanto para plântulas provenientes de frutos verdes, como as de frutos maduros. Entre os dois tipos de frutos, observou-se que as plântulas obtidas de vagem verde, obtiveram melhor desempenho sob as condições de armazenamento, em relação àquelas obtidas de vagem madura. Podem ser armazenadas por até quatro meses, mantendo 50% de sobrevivência das plântulas do lote, quando o armazenamento é feito sob baixa temperatura (10 ± 5°C) e em substrato com 30 e 60% de umidade. Após um período de armazenamento... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: Recalcitrant seeds always present difficulties for storage procedures, becoming a problem for seedling producers that often have no choice to sow them immediately after seed harvest or when they need to produce seedlings through different times by the year. Inga seeds, once harvested, lose quickly their viability, often not exceeding a period of 15 days. Species of recalcitrant seeds do not use seed banks as regeneration strategy into the natural environment. Ecological observations have shown that is common occur their natural regeneration through seedling banks. The objective of this work was to evaluate pregerminated seed storage of Inga vera Willd. from two fruit maturation stages, under different conditions of substrate humidity, and under low temperature. The collected fruits of I. vera 9were splited into two types, according to their color, between unripe and ripe. After the processing of those seeds, they were pre-germinated on substrate and stored in substrate with no water addition (control), 30, and 60% humidity under low temperature (10°C) for a year. The storage made under 30 and 60% humidity showed to be the best for both, seedlings from unripe and ripe fruits. Between two types of fruits, we observed that the seedlings from unripe fruits, presented better performance under storage conditions, when compared to those obtained from mature fruits. They can be stored for until four months, with 50% of seedling survivals when stored under low temperature (10 ± 5°C) and with 30 and 60% of substrate humidity. After a year of seedling storage it was possible to get until 10% of survival... (Complete abstract click electronic access below) Mestre

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Doust, Susan Jillian. "Seed and seedling ecology in the early stages of rainforest restoration /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18410.pdf.

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Elagael, Ali A. "Bacterial seed treatments for the control of seedling blight of wheat." Thesis, Manchester Metropolitan University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422802.

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Abuelgasim, Zeinab H. "The propagation and production of western soapberry." Thesis, Kansas State University, 1985. http://hdl.handle.net/2097/9815.

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Kittock, David L., Wallace C. Hofmann, B. Brooks Taylor, Joel Malcuit, Carl Michaud, and Peter T. Else. "Seedling Emergence Studies on Upland Cotton in Arizona in 1984." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/203916.

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Kittock, D. L., W. C. Hofmann, J. Malcuit, P. Else, and C. Michaud. "Seedling Emergence Studies on Upland Cotton in Arizona in 1985." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219703.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. Seed of 19 upland cotton varieties was planted early in the season at 3 locations to evaluate relative emergence. Variety comparisons for seedling emergence were consistent at the 3 locations. Comparison of performance of older varieties with past years showed consistent relative emergence in 7 comparisons and an apparent weak seed lot for one variety in 1985 and apparent weak seed lots for another variety in past years. Deltapine 41 has consistently been near the bottom in early season seedling emergence over years and Deltapine 61 has been below average.

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Bapela, MJ, N. Lall, JH Isaza-Martinez, T. Regnier, and JJM Meyer. "Variation in the content of naphthoquinones in seeds and seedlings of Euclea natalensis." South African Journal of Botany, 2008. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000789.

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A correlation between plant growth and accumulation of naphthoquinones (shinanolone (1), 7-methyljuglone (2) and diospyrin (3)) was investigated in seeds and seedlings of Euclea natalensis A.DC. In this study, the seeds represented the first stage whereas the second seedling stage was defined as the stage, when the radicles were about 6 cm in length. The lengths of the seedlings at the third, fourth and fifth seedling stages were 9 cm, 12 cm and 16 cm respectively. Plant materials collected from the five seedling stages were separately extracted using chloroform and the naphthoquinones were then quantified by means of High Performance Liquid Chromatography (HPLC). Shinanolone (1), which was the only naphthoquinone detectible from seeds, accumulated at variable rates (P < 0.01) and no trend could be established between its synthesis and seedling growth. The content of shinanolone (1) ranged from 87.5 mg/kg in seeds (first stage) to a high mean value of 1047 mg/kg during the fourth seedling stage. A significant correlation (P < 0.01) was found between the mean concentrations of 7-methyljuglone (2) and seedling growth. 7-Methyljuglone (2) was quantified at a high mean level of 5003 mg/kg during the third seedling stage and was not detected from the seed samples. A positive correlation (P < 0.01) was established between the concentration of diospyrin (3) and seedling stages. Diospyrin (3) was detected at an elevated mean concentration of 6182 mg/kg during the fifth seedling stage, which was higher than the other quantified naphthoquinones.

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Teaster, Neal D. Chapman Kent Dean. "A regulatory role for N-acylethanolamine metabolism in Arabidopsis thaliana seeds and seedlings." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/permalink/meta-dc-10978.

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Teaster, Neal D. "A regulatory role for N-acylethanolamine metabolism in Arabidopsis thaliana seeds and seedlings." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc10978/.

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N-Acylethanolamines (NAEs) are bioactive acylamides that are present in a wide range of organisms. Because NAE levels in seeds decline during imbibition similar to ABA, a physiological role was predicted for these metabolites in Arabidopsis thaliana seed germination and seedling development. There is also a corresponding increase of AtFAAH (fatty acid amide hydrolase), transcript levels and activity, which metabolizes NAE to ethanolamine and free fatty acids. Based on whole genome microarray studies it was determined that a number of up-regulated genes that were responsive to NAE were also ABA responsive. NAE induced gene expression in these ABA responsive genes without elevating endogenous levels of ABA. It was also determined that many of these NAE/ABA responsive genes were associated with an ABA induced secondary growth arrest, including ABI3. ABI3 is a transcription factor that regulates the transition from embryo to seedling growth, the analysis of transcript levels in NAE treated seedlings revealed a dose dependent, inverse relationship between ABI3 transcript levels and growth, high ABI3 transcript levels were associated with growth inhibition. Similar to ABA, NAE negatively regulated seedling growth within a narrow window of early seedling establishment. When seedlings are exposed to NAE or ABA within the window of sensitivity, the induction of genes normally associated with the ungerminated desiccation tolerant state resumed. The NAE tolerant FAAH overexpressor and the NAE sensitive FAAH knockout both had a NAE/ABA sensitive window similar to the wild type A. thaliana. The abi3-1 ABA insensitive mutant does not undergo growth arrest upon exposure to ABA, but NAE did induce growth arrest when treated within the sensitivity window. This evidence showed that although NAE functions within an ABA dependent pathway, it also functions in an ABA independent signaling pathway. The FAAH overexpressor is tolerant to NAE through its ability to quickly metabolize NAE from the growth media, yet it is hypersensitive to ABA. The FAAH overexpressor also displayed hypersensitivity to GA, which improved its delayed germination in non-stratified seed, while the FAAH knock out showed GA insensitivity. Overall, these results showed that NAE functions as a negative regulator of germinating seed and seedling growth in ABA dependent and independent signaling pathways, and that altered NAE metabolism may interfere with ABA/GA perception in germinating seed.

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Dissertations / Theses on the topic 'Seedling seeds'

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