Academic literature on the topic 'Maïs (Zea mays subsp. mays)'
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Journal articles on the topic "Maïs (Zea mays subsp. mays)"
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Gallavotti, Andrea, and Clinton J. Whipple. "Positional Cloning in Maize (Zea mays subsp. mays, Poaceae)." Applications in Plant Sciences 3, no. 1 (January 2015): 1400092. http://dx.doi.org/10.3732/apps.1400092.
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Gonzalez, G., V. Confalonieri, C. Comas, C. A. Naranjo, and L. Poggio. "GISHGenomic in situ hybridization reveals cryptic genetic differences between maize and its putative wild progenitor Zea mays subsp. parviglumis." Genome 47, no. 5 (October 1, 2004): 947–53. http://dx.doi.org/10.1139/g04-038.
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The aim of this paper is to test with genomic in situ hybridization the genomic affinities between maize and its putative progenitor Zea mays subsp. parviglumis. Blocking procedures were applied for the purpose of improving discrimination among chromosome regions. Unlabeled genomic DNA from Z. mays subsp. parviglumis as a blocking agent and labeled genomic DNA from maize were hybridized on maize chromosomes. On the other hand, mitotic metaphases from Z. mays subsp. parviglumis were blocked with unlabeled genomic DNA of maize and hybridized with labeled genomic DNA from Z. mays subsp. parviglumis. Both experiments showed that either maize or Z. mays subsp. parviglumis chromosomes have their own unique sequences. This means an unexpected degree of divergence if Z. mays subsp. parviglumis is the only progenitor of maize, a result that is discussed in relation to our previous genomic in situ hybridization observations and to the different scenarios proposed about the origin of maize.Key words: evolutionary relationships, Zea mays subsp. mays, teosinte, Tripsacum, molecular cytogenetics, genomic in situ hybridization (GISH).
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Sundberg, Marshall D., and Alan R. Orr. "INFLORESCENCE DEVELOPMENT IN TWO ANNUAL TEOSINTES: ZEA MAYS SUBSP. MEXICANA AND Z. MAYS SUBSP. PARVIGLUMIS." American Journal of Botany 77, no. 2 (February 1990): 141–52. http://dx.doi.org/10.1002/j.1537-2197.1990.tb13541.x.
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González, Graciela Esther, and Lidia Poggio. "Genomic affinities revealed by GISH suggests intergenomic restructuring between parental genomes of the paleopolyploid genusZea." Genome 58, no. 10 (October 2015): 433–39. http://dx.doi.org/10.1139/gen-2015-0081.
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The present work compares the molecular affinities, revealed by GISH, with the analysis of meiotic pairing in intra- and interspecific hybrids between species of Zea obtained in previous works. The joint analysis of these data provided evidence about the evolutionary relationships among the species from the paleopolyploid genus Zea (maize and teosintes). GISH and meiotic pairing of intraspecific hybrids revealed high genomic affinity between maize (Zea mays subsp. mays) and both Zea mays subsp. parviglumis and Zea mays subsp. mexicana. On the other hand, when Zea mays subsp. huehuetenanguensis DNA was probed on maize chromosomes, a lower affinity was detected, and the pattern of hybridization suggested intergenomical restructuring between the parental genomes of maize. When DNA from Zea luxurians was used as probe, homogeneous hybridization signals were observed through all maize chromosomes. Lower genomic affinity was observed when DNA from Zea diploperennis was probed on maize chromosomes, especially at knob regions. Maize chromosomes hybridized with Zea perennis DNA showed hybridization signals on four chromosome pairs: two chromosome pairs presented hybridization signal in only one chromosomal arm, whereas four chromosome pairs did not show any hybridization. These results are in agreement with previous GISH studies, which have identified the genomic source of the chromosomes involved in the meiotic configurations of Z. perennis × maize hybrids. These findings allow postulating that maize has a parental genome not shared with Z. perennis, and the existence of intergenomic restructuring between the parental genomes of maize. Moreover, the absence of hybridization signals in all maize knobs indicate that these heterochromatic regions were lost during the Z. perennis genome evolution.
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Adhikari, Sneha, Anjali Joshi, Amarjeet Kumar, and Narendra Kumar Singh. "Diversification of maize (Zea mays L.) through teosinte (Zea mays subsp. parviglumis Iltis & Doebley) allelic." Genetic Resources and Crop Evolution 68, no. 7 (March 31, 2021): 2983–95. http://dx.doi.org/10.1007/s10722-021-01170-z.
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Almeida, Cícero, Adriane leite do Amaral, José fernandes Barbosa Neto, and Maria Jane Cruz de Melo Sereno. "Conservação e germinação in vitro de pólen de milho (Zea mays subsp. mays)." Brazilian Journal of Botany 34, no. 4 (December 2011): 493–97. http://dx.doi.org/10.1590/s0100-84042011000400003.
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Almaraz-Abarca, Norma, Diana María Rivera-Rodríguez, David Arráez-Román, Antonio Segura-Carretero, José De Jesús Sánchez-González, Amanda Delgado-Alvarado, and José Antonio Ávila-Reyes. "Los fenoles del polen del género Zea." Acta Botanica Mexicana 1, no. 105 (October 1, 2013): 59. http://dx.doi.org/10.21829/abm105.2013.225.
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Se analizó la variabilidad de la composición fenólica del polen de 32 poblaciones de Zea mays subsp. mexicana, Zea mays subsp. parviglumis, Zea mays subsp. mays, Zea diploperennis, Zea perennis yZea luxurians de México y Guatemala. Los perfiles se obtuvieron por cromatografía líquida de alta presión con detector de arreglo de diodos (HPLC-DAD) y cromatografía líquida de ultra resolución acoplada a espectrómetro de masas de tiempo de vuelo (UPLC-TOF-MS). Se encontró un total de 23 compuestos fenólicos (cuatro ácidos fenólicos, 16 flavonoles y tres dihidroflavonoides). Los derivados glicósidos de quercetina (siete derivados, además de la quercetina aglicona misma) fueron las substancias predominantes en todos los analisis realizados. El compuesto principal, el más abundante y presente en la totalidad de las muestras, incluido el maíz, se identificó como quercetina-3,3’-O-diglucósido. El polen de todas las especies y subespecies de Zea analizadas mostraron patrones muy similares de fenoles acumulados; sin embargo, diferencias en los compuestos menores (ácidos fenólicos y dihidroflavonoides) permitieron discernir variaciones inter e intraespecíficas, aunque la división del género en las dos secciones Luxuriantes y Zea no fue claramente sustentada. La baja variación de los perfiles fenólicos del polen dentro del género Zea apoya la propuesta de que el maíz y algunos teocintles son grupos conespecíficos, e indica que la composición fenólica del polen fue altamente conservada en los diferentes taxa de Zea a lo largo del tiempo.
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Orozco-Ramírez, Quetzalcóatl, Hugo Perales, and Robert J. Hijmans. "Geographical distribution and diversity of maize (Zea mays L. subsp. mays) races in Mexico." Genetic Resources and Crop Evolution 64, no. 5 (April 22, 2016): 855–65. http://dx.doi.org/10.1007/s10722-016-0405-0.
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Mano, Y., and F. Omori. "Flooding tolerance in maize (Zea mays subsp. mays) F1 hybrids containing a QTL introgressed from teosinte (Zea nicaraguensis)." Euphytica 205, no. 1 (April 23, 2015): 255–67. http://dx.doi.org/10.1007/s10681-015-1449-5.
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Mano, Y., and F. Omori. "Flooding tolerance in interspecific introgression lines containing chromosome segments from teosinte (Zea nicaraguensis) in maize (Zea mays subsp. mays)." Annals of Botany 112, no. 6 (July 21, 2013): 1125–39. http://dx.doi.org/10.1093/aob/mct160.
Full textDissertations / Theses on the topic "Maïs (Zea mays subsp. mays)"
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Almeida, Cícero Carlos de Souza. "Análise citogenética e molecular em milho (Zea mays subsp. mays), teosinto (Zea mays susp. mexicana) e em seus híbridos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/4419.
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O milho é um planta anual cultivada em quase todo o mundo, consumida como ração para animais e na alimentação humana através de produtos industrializados e in natura. Existem diversos programas de melhoramento de milho no Brasil, mas no Sul são poucos os grupos que trabalham com este cereal. O desenvolvimento de populações tem sido efetuado por instituições de pesquisas, enquanto híbridos têm sido feito por companhias privadas. A variabilidade genética num programa de melhoramento assume uma grande importância, já que é o ponto de partida para o progresso genético. Em Algumas espécies, a variabilidade genética torna-se estreita a cada ciclo de seleção, diminuindo futuros progressos genéticos. Uma alternativa de ampliar a variabilidade é através de cruzamentos amplos com espécies silvestres. Estudos indicam que as espécies de teosinto são uma potencial fonte de variabilidade para importantes características agronômicas. Porém, o desenvolvimento de variedades de milho bem adaptadas, com boas características agronômicas e de rendimento, oriundas de cruzamentos com espécies silvestres necessita de um amplo estudo genético, molecular e citogenético. O objetivo deste trabalho foi caracterizar a variabilidade genética em genótipos de milho e teosinto através de marcadores moleculares e analisar a nível citogenético as populações de milho, teosinto e seus híbridos. Foi detectada variabilidade genética nas populações de milho e teosinto, sendo a população de teosinto a que apresentou maior variabilidade. Os genótipos de milho e teosinto apresentaram uma alta estabilidade meiótica, enquanto os híbridos entre milho e teosinto tiveram associações de univalentes, aderência de cromossomos, pontes e menor freqüência de quiasmas. Os resultados foram suficientes para indicar que é possível utilizar o teosinto como fonte genética em programas de melhoramento de milho.
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Terra, Tatiana de Freitas. "Variabilidade genética em populações de teosinto (Zea mays subsp. mexicana) visando a contribuição para o melhoramento genético do milho (Zea mays subsp. mays)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/32373.
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O milho (Zea mays subsp. mays) foi domesticado a cerca de 8000 anos, a partir do teosinto. A variação genética das populações domesticadas de milho pode ter sido reduzida pela deriva e pela seleção, promovida pelos primeiros agricultores. Diversos trabalhos indicam que o genoma do milho cultivado apresenta uma perda de variabilidade quando comparado ao seu ancestral silvestre. É nesta variabilidade, pertencente ao teosinto, que se podem identificar alelos de interesse agronômico para a cultura do milho, tais como os relacionados com tolerância a estresses bióticos e abióticos. Apesar da proximidade existente entre milho e teosinto, poucos trabalhos caracterizam este táxon. Os objetivos deste estudo foram analisar a variabilidade genética de duas populações de teosinto (Zea mays subsp. mexicana), a partir de análises fenotípicas, bioquímicas e moleculares e avaliar a compatibilidade dos cruzamentos dirigidos entre milho e teosinto, a partir da viabilidade dos grãos de pólen e da obtenção de populações segregantes. Os genótipos foram analisados através de oito caracteres fenotípicos, 12 bandas isoenzimáticas e 25 locos microssatélites. Os dados morfológicos demonstraram elevada diversidade genética entre as populações de teosinto (0,84), concordando com a similaridade média obtida pelos dados de esterase (0,24). Entre os 25 locos microssatélites analisados, 88% apresentaram polimorfismo, com uma média de 2,5 alelos por loco e divergência genética reduzida entre as populações (0,14). A estrutura genética das populações foi considerada moderadamente alta, com um coeficiente de endogamia de 0,44. Também foi observado moderado grau de diferenciação genética (0,15) e reduzido fluxo gênico entre as populações de teosinto. Foi observada uma elevada freqüência de grãos de pólen viáveis (acima de 90%), sugerindo ausência de barreiras citológicas entre milho e teosinto. Os cruzamentos indicaram incompatibilidade entre as duas subespécies e presença de barreiras genéticas. Este trabalho representa uma contribuição para a caracterização da variabilidade genética em teosinto e indica o potencial deste germoplasma silvestre como recurso genético para o melhoramento de milho.Maize (Zea mays subsp. mays) was domesticated about 8000 years ago, from teosinte. Genetic variability of domesticated maize populations may have been reduced due to genetic drift and early farmer’s selection. There is scientific indication that the cultivated maize genome presents a loss of variability when compared with its wild ancestral. The variability present in teosinte germplasm, which was not selected during domestication, can be used to identify alleles for important agronomic traits for maize, such as related with biotic and abiotic stress tolerance. Although teosinte is closely related to maize, there are few works on characterization of this subspecies. The objectives of this study were to analyze the genetic variability of two populations of teosinte (Zea mays subsp. mexicana), through phenotypic, biochemic and molecular analysis, and to evaluate the compatibility of oriented crosses between maize and teosinte from segregant populations and of pollen grains viability. The genotypes were analyzed through eight phenotypic traits, 12 isozymes bands and 25 microsatellites loci. The phenotypic data indicated high genetic variability (0.84) between the teosinte populations, agreeing with the average similarity (0.24) of esterases data. Amongst 25 analyzed SSR loci, 88 % presented polymorphism, with an average of 2.5 alleles/locus, and reduced genetic distance between the populations (0.14). The genetic structure of the populations was considered to be moderately high, presenting a coefficient of endogamy of 0.44. Also was observed moderate genetic differentiation (0.15) and reduced gene flow between the populations. It was observed a high frequency of viable pollen grains (above of 90%), suggesting absence of cytological barriers between maize and teosinte. The crossings had indicated incompatibility between the two subspecies and presence of genetic barriers. This work represents a contribution for the characterization of the genetic variability in teosinte and indicates the potential of this wild germplasm as genetic resource for maize breeding.
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Longchamp, Mélanie. "Etude biogéochimique du transfert du sélénium dans un système eau-plante-atmosphère : conséquences sur la physiologie du Zea mays subsp. mays (L.)." Paris 6, 2012. http://www.theses.fr/2012PA066418.
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Le sélénium (Se) est un antioxydant et un oligo-élément pour les animaux et les humains. Néanmoins, l’intervalle de concentration entre carence et toxicité est très étroit. Ce métalloïde est introduit indirectement dans la chaine alimentaire via son accumulation dans les plantes. La littérature sur ce sujet est encore restreinte et incomplète, s’effectuant couramment sur des plantes modèles et en présence de fortes concentrations en Se. Cette thèse porte sur le transfert du Se dans une plante de grande culture, le Zea mays, et les conséquences de cette accumulation sur la physiologique de la plante à travers l’étude de l’accumulation des cations essentiels (Ca, Mg, Fe, Zn, Mn, Cu). Des expérimentations en milieu contrôlé (cultures en hydroponie) ont donc été réalisées pour obtenir un ensemble d’échantillons analysés ensuite par des techniques d’analyse adéquates et sensibles (CRC-ICP-MS par exemple). Diverses modalités influençant le transfert du Se dans la plante ont ainsi été étudiées : la concentration et forme du Se source ainsi que le stade de développement de la plante. Les résultats ont montré que l’absorption racinaire, la concentration au sein de la plante ainsi que le degré de métabolisation du Se, et par conséquent les apports en Se pour les populations animales et humaines, sont fortement influencés par les trois facteurs énoncés. De plus, cette étude a mis en évidence que l’accumulation des cations au sein des plantes dépendent du Se. Ces effets peuvent être associés au déséquilibre du système de détoxification des espèces oxygénées réactives des cellules, en cohérence avec le caractère ambivalent du Se: antioxydant ou pro-oxydant selon sa concentrationSelenium is an antioxidant and an oligo-element for animals and humans. However, the concentration range between deficiency and toxicity is particularly narrow. This metalloid allotropic is introduced indirectly in the food chain via its accumulation in food plants. The literature on this subject is still restricted and incompleted, and traditionally realised on model plants and in presence of selenium in high concentrations. This thesis is about selenium transfer in a plant crop, Zea mays, and consequences of this accumulation on physiological plant through essential cations accumulation study (calcium, magnesium, iron, zinc, manganese, copper). For this, experiments in a controlled atmosphere chamber (hydroponic conditions) were performed to obtain samples then analyzed by appropriate analytical and sensitive techniques (HPLC, CRC-ICP-MS, ICP-OES or AAS-GF). Various factors influencing selenium transfer in plants have been studied: concentration and form of selenium source and stage of plant development. The results of this study showed that root absorption, concentration within the plants and their tissues, degree of selenium metabolization and volatilization, and therefore selenium intake in animals and humans, are strongly influenced by those three factors. Furthermore, this study showed that accumulation and distribution of cations within the plants depend on selenium -mainly at high concentrations. These effects may be associated with the system imbalance of reactive oxygen species detoxification in plant cells, consistent with the ambivalent nature of selenium mentioned in the literature: antioxidant or prooxidant depending on its concentration
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Blancon, Justin. "Identification des déterminants génétiques de la tolérance à la sècheresse chez le maïs par l'étude de l'évolution de l'indice foliaire vert au cours du cycle de la plante et le développement d'une méthode de phénotypage innovant." Thesis, Université Clermont Auvergne (2017-2020), 2019. http://www.theses.fr/2019CLFAC026.
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D’ici la fin du siècle, les prévisions climatiques prévoient une diminution de la quantité et de la régularité des pluies s’accompagnant d’une augmentation du risque de sècheresse en Europe et dans de nombreuses régions du monde. La création de nouvelles variétés de maïs plus tolérantes au stress hydrique est un levier indispensable pour faire face à ces contraintes futures. L’objectif principal de cette thèse est d’approfondir les connaissances des déterminismes génétiques de la tolérance à la sècheresse chez le maïs. Pour ce faire, il est proposé de disséquer ce caractère complexe en caractères physiologiques sous-jacents dont le déterminisme génétique est a priori plus simple. L’évolution de l’indice foliaire vert (GLAI : Green Leaf Area Index) au cours du cycle de la plante, par son rôle majeur dans l’interception lumineuse, la transpiration et les échanges de CO2, est un caractère secondaire prometteur pour identifier les bases génétiques de la tolérance à la sècheresse et en améliorer la compréhension. Au cours de cette thèse, nous avons développé une méthode de phénotypage haut débit permettant d’estimer la cinétique du GLAI au champ. Cette méthode combine la caractérisation multispectrale par drone et l’utilisation d’un modèle physiologique simple de GLAI. Elle permet d’estimer la cinétique du GLAI de manière continue sur l’ensemble du cycle de la plante avec une bonne précision, tout en divisant par vingt le temps nécessaire au phénotypage. Nous avons utilisé cette méthode lors de deux essais en conditions optimales et deux essais en conditions de stress hydrique pour mesurer l’évolution du GLAI au sein d’un panel de 324 lignées issues d’une population MAGIC (Multi-parent Advanced Generation Inter-Cross). Les cinétiques estimées présentent une forte héritabilité et expliquent une part significative du rendement en conditions optimales et stressées. Afin d’identifier les bases génétiques de la cinétique du GLAI, trois approches de génétique d’association longitudinales ont été comparées : une approche univariée en deux étapes, une approche multivariée en deux étapes et une approche de régression aléatoire en une étape. Ces trois approches, couplées à la forte densité des données de génotypage disponibles (près de 8 millions de marqueurs), ont permis de révéler de nombreux QTL (Quantitative Trait Loci), dont certains colocalisent avec des QTL de rendement. Enfin, nous avons démontré que les QTL de GLAI identifiés lors de cette étude pouvaient expliquer près de 20 % de la variabilité du rendement observée dans un large réseau d’expérimentations sous stress hydrique. Ce travail fournit des méthodes qui permettront une meilleure caractérisation et une meilleure compréhension des déterminismes génétiques de la cinétique du GLAI, un caractère jusqu’ici inaccessible pour les populations de taille importante. Ce caractère présente toutes les caractéristiques requises pour améliorer l’efficacité des programmes de sélection en conditions de stress hydriqueBy the end of the century, climate forecasts predict a decrease in the quantity and regularity of rainfall with an increasing risk of drought in Europe and in many regions of the world. Breeding for more tolerant varieties will be an essential lever to face these future constraints. The main objective of this work is to characterize the genetic determinisms of drought tolerance in maize. To this aim, it is proposed to dissect this complex trait into underlying physiological traits whose genetic determinism is supposed to be simpler. Green Leaf Area Index (GLAI) dynamics throughout the plant cycle, through its major role in light interception, transpiration and CO2 exchange, is a promising secondary trait to identify and better understand the genetic basis of drought tolerance. During this thesis, we developed a high-throughput method for phenotyping maize GLAI dynamics in the field. This method combines UAV multispectral imagery and a simple GLAI model. It makes possible the estimation of the dynamics of GLAI continuously throughout the whole plant cycle with good accuracy, while reducing the phenotyping time twentyfold. This method was used in two well-watered and two water-deficient trials to characterize the GLAI dynamics of 324 lines from a MAGIC population (Multi-parent Advanced Generation Inter-Cross). The estimated dynamics have a high heritability and explain a significant part of grain yield under well-watered and water-stressed conditions. To characterize the genetic basis of GLAI dynamics, three longitudinal GWAS (Genome Wide Association Study) approaches were compared: a univariate two-step approach, a multivariate two-step approach and a random regression one-step approach. These three approaches, combined with the high density of available genotyping data (nearly 8 million markers), have revealed many QTL (Quantitative Trait Loci), some of which were co-localized with yield QTL. Finally, we demonstrated that the GLAI QTL identified in this study could explain nearly 20 % of the grain yield variability observed in a large network of water-stressed experiments. This work provides methods that will enable a better characterization and understanding of the genetic determinisms of GLAI dynamics, a trait that was out of reach in large populations until now. This trait presents all the characteristics required to improve the effectiveness of selection programs under water stress conditions
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Longchamp, Melanie. "Etude biogéochimique du transfert du sélénium dans un système eau-plante-atmosphère : conséquences sur la physiologie du Zea mays subsp. mays (L.)." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00833227.
Full textAbstract:
Le sélénium (Se) est un antioxydant et un oligo-élément pour les animaux et les humains. Néanmoins, l'intervalle de concentration entre carence et toxicité est très étroit. Ce métalloïde est introduit indirectement dans la chaine alimentaire via son accumulation dans les plantes. La littérature sur ce sujet est encore restreinte et incomplète, s'effectuant couramment sur des plantes modèles et en présence de fortes concentrations en Se. Cette thèse porte sur le transfert du Se dans une plante de grande culture, le Zea mays, et les conséquences de cette accumulation sur la physiologique de la plante à travers l'étude de l'accumulation des cations essentiels (Ca, Mg, Fe, Zn, Mn, Cu). Des expérimentations en milieu contrôlé (cultures en hydroponie) ont donc été réalisées pour obtenir un ensemble d'échantillons analysés ensuite par des techniques d'analyse adéquates et sensibles (CRC-ICP-MS par exemple). Diverses modalités influençant le transfert du Se dans la plante ont ainsi été étudiées : la concentration et forme du Se source ainsi que le stade de développement de la plante. Les résultats ont montré que l'absorption racinaire, la concentration au sein de la plante ainsi que le degré de métabolisation du Se, et par conséquent les apports en Se pour les populations animales et humaines, sont fortement influencés par les trois facteurs énoncés. De plus, cette étude a mis en évidence que l'accumulation des cations au sein des plantes dépendent du Se. Ces effets peuvent être associés au déséquilibre du système de détoxification des espèces oxygénées réactives des cellules, en cohérence avec le caractère ambivalent du Se: antioxydant ou pro-oxydant selon sa concentration.
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Sobottka, Renata Pinheiro. "Moduladores naturais na proteção genética de trigo (Triticum turgidum L. subsp. durum) contra Fusarium spp. por técnica molecular e LC-MS. Aplicação de tecnologia NIR na predição de composição química de milho (Zea mays L.)." Universidade Estadual de Londrina. Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência de Alimentos, 2014. http://www.bibliotecadigital.uel.br/document/?code=vtls000189591.
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O trigo (Triticum spp.) e o milho (Zea mays L.), pertencentes à Família Poaceae, são cereais fundamentais na alimentação mundial devido à importância socioeconômica, sendo amplamente utilizados para o consumo humano e animal. O trabalho avaliou o desenvolvimento fúngico, a produção de tricoteceno (desoxinivalenol, DON) e de moduladores naturais no contexto de proteção genética em cultivares de trigo. Em paralelo, foi avaliada a tecnologia NIR na predição de atividade de água, teor de proteína, umidade e cinzas em milho, visando aplicação de método rápido, capaz de subsidiar a técnica clássica (Capítulo 2). O capítulo 1 foi executado na França e consistiu em estudo com quatro cultivares de trigo com diferente sensibilidade à fusariose, procedendo com e sem inoculo de Fusarium culmorum, seguida de análise de grão em dois estágios de desenvolvimento (cinco dias após inoculação e na maturação). A análise em grãos de trigo consistiu na detecção de DON, composição em ácidos fenólicos (solúveis e ligados à parede celular) por LC/MS e determinação do gene Tri5 por PCR em tempo real. O cultivar de trigo resistente limitou significativamente o desenvolvimento de Fusarium culmorum e a contaminação por DON (p<0,05). Glumas de trigo de cultivar resistente apresentaram-se ricas em ácido clorogênico e flavonas, sugerindo participação na resistência contra Fusarium spp. e produção de DON. Estudo em moduladores naturais com potencial inibidor na biossíntese de tricotecenos deve ser prosseguido visando inocuidade de alimentos, enfocada também na minimização de agrotóxicos. O capítulo 2 avaliou a aplicação da tecnologia NIR na predição de atividade de água (aw), teor de proteína, umidade e cinzas de milho cultivado sob quatro diferentes populações de planta (densidade, 60, 75, 90 e 105 mil plantas ha-1) sob cinco doses de nitrogênio (0, 60, 120, 180 e 240 kg ha-1). O teor de proteína em milho cultivado sob mesma densidade de planta aumentou com os níveis de adubação (dose de nitrogênio, p<0,05). No entanto, não se observou diferença significativa entre grãos de milho tratado com a mesma dose de nitrogênio, mas com diferente densidade de planta (p<0,05). As amostras de milho foram digitalizadas na faixa do visível / NIR de 400 2500 nm. O melhor coeficiente de predição foi obtido para a proteína (R2cv=0,90), revelando uma forte relação entre informação espectral e teor de proteína. Os modelos para três parâmetros (proteína, aw e umidade) apresentaram a razão de erro padrão de calibração e desvio padrão (RPD) entre 2,4 e 4,2. Com exceção de cinzas, os modelos obtidos apresentam perfil adequado para o rastreio de constituintes proteína, aw e umidade em milho, no contexto de monitoramento rápido em planta de processamento industrial.Wheat (Triticum sp.) and maize (Zea mays L.), belonging to the Poaceae family, are important cereals on the global socio-economy, being widely used for human and animal consumption. The study evaluated the fungal growth and trichothecene production (deoxynivalenol, DON) in wheat cultivars on the genetic protection context (Chapter 1). In parallel, it was evaluated the application of NIR technology for prediction of water activity, protein, moisture and ash contents in maize, seeking the application of this rapid method being capable for subsidizing the classical technique (Chapter 2). Chapter 1 was executed in France and evaluated four wheat cultivars with different sensitivity to Fusarium infection, with and without inoculum of Fusarium culmorum, followed by analysis of grains in two stages of development (five days after inoculation and at maturity stage). The analysis of wheat grains was the determination of DON, phenolic acids composition (soluble and bound to the cell wall) by LC/MS and the Tri5 gene determination by real-time PCR. The resistant wheat cultivar significantly limited the development of Fusarium culmorum and DON contamination (p <0.05). Glumes of resistant wheat cultivar showed high content on chlorogenic acid and flavones, suggesting involvement on resistance against Fusarium sp. and DON production. Study on natural modulators with potential inhibitor on the biosynthesis of trichothecenes should be pursued in order to ensure food safety, also focused on reduction of pesticide application. Chapter 2 evaluated the application of NIR technology for prediction of water activity (aw), protein, moisture and ash contents in maize from four different plant density (60, 75, 90 and 105 thousand plants ha-1) with five doses of nitrogen (0, 60, 120, 180 and 240 kg ha-1). Maize samples from the same plant density had their protein content increased with levels of fertilization (doses of nitrogen, p <0.05). However, no significant difference was observed among maize treated with the same dose of nitrogen, but with different plant density (p <0.05). The maize samples were scanned in the visible / NIR range of 400 - 2500 nm. The best coefficient of prediction was obtained for protein (R2cv=0.90), which revealed a strong relationship between spectral information and protein content. The models for three parameters (protein, moisture and aw) showed the ratio of standard error of calibration and standard deviation (RPD) between 2.4 and 4.2. Except for ash, the models obtained showed satisfactory for screening purposes of constituents - protein, aw and moisture - in maize, under the context of rapid monitoring of industrial processing plant.
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La, Hovary Christophe. "Le désherbage mécanique complet dans le maïs, Zea mays L." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ49031.pdf.
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Moulia, Bruno. "Etude mécanique du port foliaire du maïs (Zea mays L. )." Bordeaux 1, 1993. http://www.theses.fr/1993BOR10576.
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Lauga, Béatrice. "Etude génétique et moléculaire de déficiences polliniques chez Zea mays L." Pau, 1996. http://www.theses.fr/1996PAUU3040.
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Des observations cytologiques et morphologiques ont été utilisées pour identifier l'origine des déficiences polliniques de trois lignées de maïs. Elles ont permis d'attribuer la cause de ce phénomène à trois événements distincts. Deux déficiences résultent d'une réduction de la taille de la panicule qui se traduit par une réduction du nombre d'épillets, des nombres de ramifications primaires et secondaires et de la longueur du maître brin. Ces caractères sont souvent accompagnés de surcroît par une réversion du sexe de l'inflorescence mâle. La troisième déficience pollinique est en partie attribuée à des anomalies méïotiques qui se produisent au cours de la microsporogénèse. Ces anomalies contribuent à la présence de pollen abortif au sein de la population de grain de pollen. L'analyse du déterminisme de la réversion du sexe a permis de démontrer l'influence simultanée de facteurs génétiques et environnementaux. La manifestation de ce caractère est consécutive à la présence d'un allèle majeur récessif chez deux des lignées déficientes. Son expression peut être influencée par les facteurs du milieu. La cartographie de 48 marqueurs Rflps et l'analyse de ségrégation des caractères inflorescentiels mâles ont conduit à l'identification et à la localisation de six régions chromosomiques impliquées dans le contrôle du nombre de ramifications primaires, de ramifications secondaires et de la longueur du maître brin. Enfin l'existence d'anomalies méïotiques nous a orientés à contribuer à la compréhension de la microsporogénèse chez Zea mays. L'identification de gènes spécifiquement exprimés au cours de la microsporogénèse a été engagée. A partir d'un criblage différentiel d'une banque d'ADNC issue de jeunes anthères contenant des cellules mère du pollen en preméïose et en méïose, huit clones issus de gènes spécifiquement exprimés au cours de la microsporogénèse ont été isolés.
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Lejeune, Pierre. "Etude physiologique de l'initiation de l'inflorescence femelle chez le maïs (Zea mays L. )." Lyon 1, 1995. http://www.theses.fr/1995LYO10286.
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Chez certains genotypes de mais, utilises comme geniteurs en production de semences, un avortement de l'inflorescence femelle a ete observe qui se manifeste par la substitution de l'epi mature par une structure sterile, ressemblant a une feuille. La frequence de ces avortements varie selon l'annee, le lieu, et la date de semis, ce qui indique l'influence d'un facteur climatique. L'avortement de l'epi a ete induit en conditions controlees par un traitement au froid, donne juste avant l'initiation de la panicule. Le meme stress applique avant ou apres l'initiation de la panicule, soit induit une reaction d'adaptation, soit n'a pas d'effet. L'etude en microscopie electronique a balayage des bourgeons axillaires anormaux indique que l'avortement resulte d'un arret de l'activite du meristeme axillaire, juste apres son apparition a l'aisselle de la feuille, suivi d'un allongement du prophyllum (1ere spathe). L'application exogene d'une auxine (2,4-d) ou d'une cytokinine (benzyladenine) peut, respectivement, induire ou reverser l'avortement cause par le stress froid. La benzyladenine stimule egalement l'initiation des bourgeons axillaires en conditions non stressantes. L'analyse par hplc/ria du contenu endogene en regulateurs de croissance indique que le stress froid induit un changement dans la balance hormonale de la plante, avec une chute marquee en cytokinines. Ces resultats suggerent que les cytokinines representent un facteur determinant dans l'initiation de l'epi chez le mais
Book chapters on the topic "Maïs (Zea mays subsp. mays)"
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"Maize (Zea mays subsp. mays)." In Safety Assessment of Transgenic Organisms, 47–78. OECD Publishing, 2008. http://dx.doi.org/10.1787/9789264053465-4-en.
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"Section 3 - Maize (ZEA MAYS SUBSP. MAYS)." In Safety Assessment of Transgenic Organisms, Volume 1, 47–78. OECD, 2006. http://dx.doi.org/10.1787/9789264095380-6-en.
Full textConference papers on the topic "Maïs (Zea mays subsp. mays)"
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Kopecký, Marek, Jaroslav Bernas, Ladislav Kolář, and Pavlína Hloucalová. "MONITORING OF ENERGY GAIN AND EROSION PROTECTION OF CORN AND TALL WHEATGRASS CROPS IN THE CONDITIONS OF THE CZECH REPUBLIC." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.084.
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With the growing energy demand of the society and the increased requirements for ecological aspects of obtaining and utilizing energies, renewable energy sources have been getting to the forefront. In the conditions of Central Europe, transformation of biomass to biogas through anaerobic digestion appears to be promising. The article describes the results of a field experiment carried out in an experimental site of the University of South Bohemia in České Budějovice (South Bohemia, Czech Republic). The goal of the article is to compare the conventionally grown corn (Zea mays L., hybrid Simao), the areas of which have increased considerably as a result of the development of biogas stations, and the alternative perennial grass called tall wheatgrass (Elymus elongatus subsp. ponticus cv. Szarvasi-1), which is, according to the literature, well positioned to replace corn. The harvests of the plants took place in 2013-2015, and tall wheatgrass was cut twice per season. A number of aspects – dry phytomass yield, specific methane yield and hectare methane yield – were monitored. In addition, the long-term soil loss by water erosion was calculated through the Universal Soil Loss Equation for both species of energy crops. In terms of yield parameters and methane production, better results were achieved by corn, given the average energy gain 238 GJ·ha-1 as compared to 126 GJ·ha-1 for tall wheatgrass. The protection of the soil surface from water erosion by corn appears to be insufficient and, in this criterion, it absolutely lags behind the anti-erosion abilities of tall wheatgrass, which protects soil incomparably better.