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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Comportamento fenotípico e genotípico e desenvolvimento de cultivares híbridas de manjericão / Phenotypic and genotypic behavior and development of hybrids cultivars of basil

Santana, Aléa Dayane Dantas de 25 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Basil (Ocimum basilicum L.) is a medicinal, aromatic and spicy species, which has wide variability and consecutively potential for obtaining new cultivars that add characters of interest. To obtain information about the genotype it is necessary to use phenotypic and genetic parameters, since they may estimate the genotypic behavior from the phenotype. Thus, the aim of this work was to evaluate the phenotypic and genotypic performance of basil hybrids and cultivars grown in four crop years, as well as developing new hybrid cultivars. The experiments were conducted in a randomized block design, with three replications. Five hybrids and four parental cultivars constituted the treatments. We evaluated agronomic (dry weight of aerial part, essential oil content and yield) and chemical (linalool, 1,8-cineol, neral, geranial and (E)-methyl cinnamate content in the essential oils) characteristics. The clustering of the means was performed, and the parameters were estimated: genotypic quadratic component ; residual variance ; genotypic coefficient of determination ; coefficient of genetic variation ; coefficient of environmental variation ; ratio, and coefficient of phenotypic and genotypic correlation . All variables expressed high percentages of (higher than 90 %), (higher than 30 %) and ratio (higher than 2 %). The greatest genotypic correlation occurred between neral and geranial ( ranging from 0.949 to 1.005). Most of the variation among the studied variables resulted from the genetic variation, which resulted in differentiated inheritance of characters, agronomic and chemical performance. Linalool was the main compound of most genotypes. The hybrid Cinnamon x Maria Bonita had the highest dry weight of aerial part (90.72 g plant-1) and essential oil yield (2.37 ml plant-1) and contained two main components, methyl cinnamate (41.93 %) and linalool (34.92 %). The hybrid Sweet Dani x Cinnamon presented as a main component (E)-methyl cinnamate (60.15 %), with content superior than its parental ´Cinnamon (47.67 %), besides exhibiting 16.01 % of linalool, which was absent on its parental ´Sweet Dani´. The main component of the hybrid Sweet Dani x Maria Bonita were linalool (58.83 %), as well as geranial (15.20 %) and neral (11.46 %), which were absent on its parental ´Maria Bonita´. The hybrids Sweet Dani x Maria Bonita, Cinnamon x Maria Bonita e Sweet Dani x Cinnamon, were distinct in new hybrid cultivars, denominated: ´Vitória´, and ´Norine´ and ´Natalina´, respectively. / O manjericão (Ocimum basilicum L.) é uma espécie medicinal, aromática e condimentar que possui ampla variabilidade e, consecutivamente, potencialidade de obtenção de novas cultivares que agreguem caracteres de interesse. Para obter informações sobre o genótipo é necessário utilizar parâmetros fenotípicos e genéticos, já que estes podem estimar o comportamento genotípico a partir do fenótipo. Dessa forma, objetivou-se com este trabalho, avaliar o comportamento fenotípico e genotípico de híbridos e cultivares de manjericão cultivados em quatro anos agrícolas, como também desenvolver novas cultivares híbridas. O delineamento experimental foi blocos casualizados, com três repetições. Cinco híbridos e quatro cultivares parentais constituíram os tratamentos. Foram avaliadas características agronômicas (massa seca de parte aérea, teor e rendimento de óleo essencial) e químicas (teor de linalol, 1,8-cineol, neral, geranial e (E)-cinamato de metila nos óleos essenciais). Foi realizado o agrupamento das médias e foram estimados os parâmetros: componente quadrático genotípico; variância residual; coeficiente de determinação genotípico; coeficiente de variação genética ; coeficiente de variação ambiental ; razão e coeficiente de correlação fenotípica e genotípica. Todos os caracteres expressaram alta porcentagem de (acima de 90 %), (acima de 30 %) e da razão (acima de 2 %). A maior correlação genotípica foi mantida entre neral e geranial (de 0,949 a 1,005). A maior parte da variação encontrada para os caracteres estudados é determinada pela variação genética dos genótipos, o que resultou na herança dos caracteres e no desempenho agronômico e químico diferenciado. Constatou-se que linalol foi o composto majoritário da maioria dos genótipos. O híbrido Cinnamon x Maria Bonita obteve o melhor desempenho de massa seca de parte aérea (90,72 g planta-1) e rendimento de óleo essencial (2,37 mL planta-1) e apresentou dois compostos majoritários, (E)-cinamato de metila (41,93 %) e linalol (34,92 %). O híbrido Sweet Dani x Cinnamon apresentou como composto majoritário (E)-cinamato de metila (60,15 %), com teor superior ao seu parental ´Cinnamon (47,67 %), além de exibir 16,01 % de linalol, ausente no seu parental ´Sweet Dani . O híbrido Sweet Dani x Maria Bonita, apresentou como composto majoritário linalol (58,83 %), assim como, geranial (15,20 %) e neral (11,46 %), ausentes no seu parental ´Maria Bonita . Os híbridos Sweet Dani x Maria Bonita, Cinnamon x Maria Bonita e Sweet Dani x Cinnamon, foram distintos em novas cultivares híbridas, denominadas, ´Vitória' , ´Norine' e ´Natalina´, respectivamente.
252

Comportamento fenotípico e genotípico e desenvolvimento de cultivares híbridas de manjericão / Phenotypic and genotypic behavior and development of hybrids cultivars of basil

Santana, Aléa Dayane Dantas de 25 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Basil (Ocimum basilicum L.) is a medicinal, aromatic and spicy species, which has wide variability and consecutively potential for obtaining new cultivars that add characters of interest. To obtain information about the genotype it is necessary to use phenotypic and genetic parameters, since they may estimate the genotypic behavior from the phenotype. Thus, the aim of this work was to evaluate the phenotypic and genotypic performance of basil hybrids and cultivars grown in four crop years, as well as developing new hybrid cultivars. The experiments were conducted in a randomized block design, with three replications. Five hybrids and four parental cultivars constituted the treatments. We evaluated agronomic (dry weight of aerial part, essential oil content and yield) and chemical (linalool, 1,8-cineol, neral, geranial and (E)-methyl cinnamate content in the essential oils) characteristics. The clustering of the means was performed, and the parameters were estimated: genotypic quadratic component ; residual variance ; genotypic coefficient of determination ; coefficient of genetic variation ; coefficient of environmental variation ; ratio, and coefficient of phenotypic and genotypic correlation . All variables expressed high percentages of (higher than 90 %), (higher than 30 %) and ratio (higher than 2 %). The greatest genotypic correlation occurred between neral and geranial ( ranging from 0.949 to 1.005). Most of the variation among the studied variables resulted from the genetic variation, which resulted in differentiated inheritance of characters, agronomic and chemical performance. Linalool was the main compound of most genotypes. The hybrid Cinnamon x Maria Bonita had the highest dry weight of aerial part (90.72 g plant-1) and essential oil yield (2.37 ml plant-1) and contained two main components, methyl cinnamate (41.93 %) and linalool (34.92 %). The hybrid Sweet Dani x Cinnamon presented as a main component (E)-methyl cinnamate (60.15 %), with content superior than its parental ´Cinnamon (47.67 %), besides exhibiting 16.01 % of linalool, which was absent on its parental ´Sweet Dani´. The main component of the hybrid Sweet Dani x Maria Bonita were linalool (58.83 %), as well as geranial (15.20 %) and neral (11.46 %), which were absent on its parental ´Maria Bonita´. The hybrids Sweet Dani x Maria Bonita, Cinnamon x Maria Bonita e Sweet Dani x Cinnamon, were distinct in new hybrid cultivars, denominated: ´Vitória´, and ´Norine´ and ´Natalina´, respectively. / O manjericão (Ocimum basilicum L.) é uma espécie medicinal, aromática e condimentar que possui ampla variabilidade e, consecutivamente, potencialidade de obtenção de novas cultivares que agreguem caracteres de interesse. Para obter informações sobre o genótipo é necessário utilizar parâmetros fenotípicos e genéticos, já que estes podem estimar o comportamento genotípico a partir do fenótipo. Dessa forma, objetivou-se com este trabalho, avaliar o comportamento fenotípico e genotípico de híbridos e cultivares de manjericão cultivados em quatro anos agrícolas, como também desenvolver novas cultivares híbridas. O delineamento experimental foi blocos casualizados, com três repetições. Cinco híbridos e quatro cultivares parentais constituíram os tratamentos. Foram avaliadas características agronômicas (massa seca de parte aérea, teor e rendimento de óleo essencial) e químicas (teor de linalol, 1,8-cineol, neral, geranial e (E)-cinamato de metila nos óleos essenciais). Foi realizado o agrupamento das médias e foram estimados os parâmetros: componente quadrático genotípico; variância residual; coeficiente de determinação genotípico; coeficiente de variação genética ; coeficiente de variação ambiental ; razão e coeficiente de correlação fenotípica e genotípica. Todos os caracteres expressaram alta porcentagem de (acima de 90 %), (acima de 30 %) e da razão (acima de 2 %). A maior correlação genotípica foi mantida entre neral e geranial (de 0,949 a 1,005). A maior parte da variação encontrada para os caracteres estudados é determinada pela variação genética dos genótipos, o que resultou na herança dos caracteres e no desempenho agronômico e químico diferenciado. Constatou-se que linalol foi o composto majoritário da maioria dos genótipos. O híbrido Cinnamon x Maria Bonita obteve o melhor desempenho de massa seca de parte aérea (90,72 g planta-1) e rendimento de óleo essencial (2,37 mL planta-1) e apresentou dois compostos majoritários, (E)-cinamato de metila (41,93 %) e linalol (34,92 %). O híbrido Sweet Dani x Cinnamon apresentou como composto majoritário (E)-cinamato de metila (60,15 %), com teor superior ao seu parental ´Cinnamon (47,67 %), além de exibir 16,01 % de linalol, ausente no seu parental ´Sweet Dani . O híbrido Sweet Dani x Maria Bonita, apresentou como composto majoritário linalol (58,83 %), assim como, geranial (15,20 %) e neral (11,46 %), ausentes no seu parental ´Maria Bonita . Os híbridos Sweet Dani x Maria Bonita, Cinnamon x Maria Bonita e Sweet Dani x Cinnamon, foram distintos em novas cultivares híbridas, denominadas, ´Vitória' , ´Norine' e ´Natalina´, respectivamente.
253

Diversidade química, genética e estudo do potencial formicida de óleos essenciais de Eplingiella fruticosa (Salzm. Ex Benth) Harley & J.F.B. Pastore / Chemical and genetic diversity and study of the formicidal potential of the essential oils of Eplingiella fruticosa (Salzm. ex Benth.) Harley & J.F.B. Pastore

Silva, Dennis Crystian 11 October 2017 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Eplingiella fruticosa Salzm. ex Benth., ex Hyptis fruticosa is a shrubby plant of the family Lamiaceae, found mainly on the coast of northeastern Brazil. This study aimed to characterize the chemical and genetic properties of the essential oil of E. fruticosa native to the state of Sergipe. Native populations were collected in 11 municipalities in the state of Sergipe. The essential oils from dry leaves were collected by hydrodistillation and analyzed by GC/MSFID. The mean essential oil content ranged between 0.75 and 1.28%. The chemical and clustering analysis of the essential oils revealed two clusters, based on the higher contents of constituents. The first cluster consisted of 15 plants and had bicyclogermacrene (6.29- 16.24%), spathulenol (7.59-15.23%), β-caryophyllene (5.77-12.97 %), and caryophyllene oxide (5.00-11.90%) as major constituents. The second cluster consisted of seven plants and had 1,8-cineol (8.96-15.51%), α-pinene (5.46-13.77%), and camphor (4,08-11.40%) as major constituents. The analysis of genetic diversity by ISSR comprised samples of 100 plants and used eight primers. Results of the clustering analysis by the Neighbor-Joining method formed three clusters: Cluster I, consisting of 50 plants, mainly from the municipalities of Areia Branca, Estância, Japaratuba, Moita Bonita, Pirambu, and Salgado; Cluster II, formed by 21 plants, nine representatives of the municipality of Itaporanga D'Ajuda and 13 representatives of other municipalities; Group III, made up of 29 plants, mainly from the municipalities of Malhada dos Bois and São Cristóvão. The lowest genetic distance was observed between plants EPF94 and EPF96 (0.250), and the highest genetic distance was observed between plants EPF50 and EPF96 (0.9778). The Shannon index presented a mean value of 0.42, and diversity was considered as moderate. Heterozygosity reached a mean value of 0.267 and was considered as low. The polymorphic information content (PIC = 0.253) was considered as moderately informative. The essential oils of four E. fruticosa genotypes were toxic to workers of Acromyrmex balzani, requiring 4.54-6.78 μL.L-1 of oil to cause 50% mortality of the ants. When applied alone, camphor and 1,8-cineol were more effective than the essential oil; conversely, β-caryophyllene and caryophyllene oxide were less toxic. Treatments reduced the survival rate of A. balzani throughout the exposure time, especially the essential oils of the genotypes EPF303 and EPF1103 and their respective constituents isolated, which presented the shortest lethal times. The treatments affected the ants' behavior, confirming the repellency of the essential oils tested in this study. Results revealed the existence of chemical variability among E. fruticosa plants of the state of Sergipe and intermediate genetic diversity among plants. The essential oils and the constituents isolated have the potential for the development of effective products to control leaf-cutting ants. / Eplingiella fruticosa Salzm. ex Benth., ex Hyptis fruticosa, é uma planta arbustiva da família Lamiaceae, encontrada principalmente na costa do nordeste brasileiro. Objetivou-se com o presente estudo realizar a caracterização química, genética e avaliar o potencial formicida do óleo essencial de plantas nativas de E. fruticosa do Estado de Sergipe. Foram realizadas coletas de populações nativas em 11 municípios do Estado de Sergipe. Os óleos essenciais foram obtidos de folhas secas por hidrodestilação e analisados por CG/EM-DIC. Os teores médios dos óleos essenciais variaram de 0,75 a 1,28%. Pela análise química e de agrupamento dos óleos essenciais, foi definido a formação de dois grupos, baseado nos maiores teores dos compostos. O primeiro grupo foi constituído por 15 plantas e caracterizou-se pela presença de biciclogermacreno (6,29-16,24%), espatulenol (7,59-15,23%), β-cariofileno (5,77-12,97%) e óxido de cariofileno (5,00-11,90%) como compostos majoritários. O segundo grupo foi constituído por sete plantas e caracterizado pela presença majoritária dos compostos, 1,8- cineol (8,96-15,51%), α-pineno (5,46-13,77%) e cânfora (4,08-11,40%). Para análise da diversidade genética por ISSR, amostras de 100 plantas foram analisadas utilizando oito primers. Os resultados da análise de agrupamento obtidos utilizando o método Neighbor Joining distribuíram os indivíduos em três grupos: o grupo I foi constituído por 50 plantas provenientes principalmente dos municípios de Areia Branca, Estância, Japaratuba, Moita Bonita, Pirambu e Salgado; o grupo II foi formado por 21 plantas, sendo nove representantes do município de Itaporanga D’Ajuda e 13 representantes de outros municípios; o grupo III foi formado por 29 plantas, sendo representado principalmente pelos municípios de Malhada dos Bois e São Cristóvão. A menor distância genética existente ocorreu entre as plantas EPF94 e EPF96 (0,250) e a maior ocorreu entre as plantas EPF50 e EPF96 (0,9778). O índice de Shannon apresentou um valor médio de 0,42 e a diversidade foi considerada moderada. A heterozigosidade atingiu um valor médio de 0,267 e foi considerada baixa. O conteúdo de informação polimórfica (PIC=0,253) é considerado moderadamente informativo. Os óleos essenciais de quatro genótipos de E. fruticosa mostraram-se tóxicos a operárias de Acromyrmex balzani e foram necessários 4,54-6,78 μL.L-1 de óleo para causar 50% de mortalidade nas formigas. Quando aplicados isoladamente, cânfora e 1,8-cineol foram mais potentes que os óleos essenciais, enquanto β-cariofileno e óxido de cariofileno foram menos tóxicos. Os tratamentos reduziram a sobrevivência de A. balzani ao longo do tempo de exposição, com destaque para os óleos essenciais dos genótipos EPF303 e EPF1103, assim como os respectivos constituintes isolados, que apresentaram os menores tempos letais. O comportamento de caminhamento das formigas foi alterado em função da aplicação dos tratamentos e verificou-se que os óleos essenciais testados são repelentes. Os resultados indicam que há variabilidade química entre as plantas de E. fruticosa do Estado de Sergipe, a diversidade genética das plantas foi intermediária e que os óleos essenciais e os constituintes isolados apresentam potencial para o desenvolvimento de produtos eficazes no controle de formigas cortadeiras. / São Cristóvão, SE
254

Divergência genética e predição de valores genotípicos em soja / Genetic divergence and genotypic values prediction in soybean

Godoi, Cláudio Roberto Cardoso de 07 May 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-16T13:14:38Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Cláudio Roberto Cardoso de Godoi - 2014.pdf: 1446327 bytes, checksum: 78154341b9ccb5964b8508984eea19e1 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-16T13:48:33Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Cláudio Roberto Cardoso de Godoi - 2014.pdf: 1446327 bytes, checksum: 78154341b9ccb5964b8508984eea19e1 (MD5) / Made available in DSpace on 2015-01-16T13:48:33Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese - Cláudio Roberto Cardoso de Godoi - 2014.pdf: 1446327 bytes, checksum: 78154341b9ccb5964b8508984eea19e1 (MD5) Previous issue date: 2014-05-07 / Soybean breeding programs practice selection of high genetic value genotypes with two main objectives: a) to use them as parents in the hybridization process (first stage of the program), and b) to indicate them as new cultivars (final stage of the program). In this context, a first study used microsatellite markers (SSR) to assess the genetic diversity of soybean germplasm adapted to the Brazilian conditions. The experimental material consisted of 192 accessions, which included both introductions and Brazilian germplasm. The genetic divergence was assessed by descriptive analysis and the Rogers-W genetic distance. A total of 222 alleles were identified in the 37 genotyped loci, with an average of six alleles and a range of 2 to 14 alleles per locus. The genotypes were clustered according to the origin of the germplasm, and resulted in two groups: one group formed by introductions and other by Brazilian genotypes. Eighty five percent of the genetic distances estimates were above 0.70, suggesting that the assessed germplasm has good potential for hybridization in soybean breeding programs. It was concluded that the SSR markers are useful to identify divergent genotypic groups, as well as genotypic combinations with high genetic variability. It also became clear that the use of introduced germplasm ensures the incorporation of alleles necessary to increase the genetic base of soybeans and, consequently, the variability needed for the selective process. In a second study, the mixed model approach was used to assess some strategies of estimation and prediction of genotypic values for grain yield in the soybean regional yield trials. A total of 111 genotypes classified into three maturity groups were sown in up to 23 experiments in Central Brazil. The experiments were carried out in randomized complete block designs, with three replications. The biometrical analyses followed the fixed model and mixed model approaches, in the latter case assuming the genotypic effects as random. In the mixed model approach, analyses were made with or without information from the relationship estimates obtained either by genealogy or SSR markers, arranged in a genotypic covariance matrix (G). Also, in a context of spatial analysis, different structures were used in the residual covariance matrix (R) for each mixed model adjusted. The following conclusions were obtained: i) the fixed model analysis is adequate to estimate genotypic values in soybean trials with balanced data and orthogonal design; ii) under such conditions and intermediate to low heritability, the inclusion of relationship information associated to G matrix, although does not ensure the best fit models, improves the precision in predicting genotypic values; iii) the use of spatial structures associated to R matrix, in presence of the residual autocorrelation, improves the goodness of model fit to the data; and, iv) the choice of model for the analysis does not change the ranking of the genotypes in high heritability situations and, therefore, does not impact significantly on the selection of superior genotypes. / Os programas de melhoramento de soja visam à seleção de genótipos de alto valor genético, com a finalidade de uso principalmente em duas de suas etapas: a) como genitores no processo de hibridação (fase inicial); e, b) para indicação como nova cultivar (fase final). Nesse contexto, num primeiro estudo avaliou-se, por meio de marcadores microssatélites (SSR), a diversidade genética em germoplasma de soja adaptado às condições brasileiras. O material experimental constituiu-se de 192 acessos, entre introduções e germoplasma de origem nacional. Na avaliação da divergência genética, considerou-se a análise descritiva e a distância genética de Rogers-W. Nos 37 locos genotipados, identificaram-se 222 alelos, com média de seis alelos por loco e variação de 2 a 14 alelos. O agrupamento dos genótipos mostrou-se associado à origem do germoplasma, resultando em dois grupos: um introduzido e outro brasileiro. Das estimativas de distâncias genéticas obtidas, 85% foram superiores a 0,70, indicando bom potencial do germoplasma para hibridações em programas de melhoramento da soja. Concluiu-se que os marcadores SSR são úteis na identificação de grupos genotípicos divergentes, bem como de combinações de alta variabilidade genética. Ademais, o uso de germoplasma introduzido garante a incorporação de alelos necessários à ampliação da base genética da espécie e, consequentemente, da variabilidade necessária para uso no processo seletivo. Num segundo estudo, no contexto da análise de modelos mistos, avaliaram-se estratégias de estimação e predição de valores genotípicos para produtividade de grãos, a partir de ensaios de competição final de linhagens de soja. Os genótipos, em número de 111 e classificados em três grupos de maturação, foram semeados em até 23 experimentos conduzidos na região central do Brasil. Os experimentos foram conduzidos no delineamento de blocos completos casualizados, com três repetições. Nas análises biométricas adotaram-se as abordagens de modelo fixo e de modelo misto, neste caso, assumindo-se efeitos genotípicos como aleatórios. Na última abordagem, consideraram-se ainda análises com ou sem uso da informação de parentesco genético, obtida a partir de genealogias ou por marcadores SSR, e associada à matriz de covariâncias dos efeitos aleatórios (G). Para cada modelo, num contexto de análise espacial, adotaram-se também distintas estruturas para a matriz de covariâncias residuais (R). Concluiu-se, então, que: i) a análise com modelo fixo é adequada para estimar efeitos genotípicos em soja, sob condições de balanceamento dos dados e ortogonalidade do delineamento; ii) sob tais condições, a inclusão da informação de parentesco associada à matriz G, embora não garanta melhor ajuste aos modelos, sob herdabilidade moderada ou baixa, melhora a precisão das predições de valores genotípicos; iii) o uso de estruturas espaciais associadas à matriz R, na presença de autocorrelação residual, melhora o ajuste estatístico dos modelos; e, iv) corrobora-se a tese de que, sob alta herdabilidade, a escolha do modelo de análise não altera o posicionamento relativo dos genótipos, e, portanto, não impacta significativamente na seleção de genótipos superiores.
255

Seleção recorrente genômica como estratégia para aceleração de ganhos genéticos em arroz / Genomic recurrent selection as strategy to accelerate genetic gains in rice

Morais Júnior, Odilon Peixoto de 15 December 2016 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-18T14:36:39Z No. of bitstreams: 2 Tese - Odilon Peixoto de Morais Júnior - 2016.pdf: 4169553 bytes, checksum: 1841a99cece6656c30b62fbd8fda9da5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-18T14:36:54Z (GMT) No. of bitstreams: 2 Tese - Odilon Peixoto de Morais Júnior - 2016.pdf: 4169553 bytes, checksum: 1841a99cece6656c30b62fbd8fda9da5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-18T14:36:54Z (GMT). No. of bitstreams: 2 Tese - Odilon Peixoto de Morais Júnior - 2016.pdf: 4169553 bytes, checksum: 1841a99cece6656c30b62fbd8fda9da5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Genetic gains for quantitative traits associated with the maintenance of genetic variability are important factors in recurrent selection programs. With advances in the area of statistical genomics, selection strategies potentially faster to achieve genetic gains are being developed, such as genomic selection. Using a subtropical population of irrigated rice (CNA12S), conducted during three cycles of recurrent selection, this study had as general objective to evaluate the potential of use of genomic recurrent selection (GRS) in a rice breeding program. Three specific studies were developed. In the first chapter, the efficiency of the genotypic recurrent selection (RS) used in the Embrapa’s rice breeding program was evaluated, in order to obtain genetic gains and maintain the population genetic variability. Ten yield trials of S1:3 progenies were used in the analyses. The evaluated traits were grain yield, plant height and days-to-flowering. Variance and covariance components were obtained using Bayesian approach. Using single nucleotide polymorphisms (SNP) markers, the population diversity and genetic structure also were estimated. Adjusted means of progenies in each cycle were computed and, genetic progress was estimated by generalized linear regression using frequentist approach. The magnitudes of effective population size and genetic variance indicated maintenance of genetic variability over selection cycles. The genetic progress achieved for grain yield was 760 kg ha-1 per cycle (1.95% per year), and for days-to-flowering, it was -6.3 days per cycle (-1.28% per year). It was concluded that the genetic progress already achieved and the genetic variability available in the population demonstrate the efficiency of RS in the improvement of rice populations. In the second chapter, in the context of genomic selection, the relative efficiency of GRS on RS was assessed, as well as the accuracy of different models of genomic prediction, in order to propose a GRS scheme for population breeding of self-pollinating species such as rice. In this study, the genetic material was the S1:3 progenies yield trial of the third selection cycle. From a group of 196 progenies that were phenotyped for eight traits with different heritabilities and genetic architectures, a group of 174 progenies was genotyped for SNP markers. Ten predictive models were fitted to the data set. The proposed GRS scheme, when compared to the RS method, showed higher efficiency, especially in genetic gain per unit of time. From the predictive models assessed, HBLUP (hybrid best linear unbiased prediction, using hybrid relationship matrix based in pedigree and SNP markers) and RForest (random forest) have greater potential for genomic prediction in irrigated rice, given the high accuracy of their predictions for a number of traits. The HBLUP model was notoriously superior for more complex traits, such as grain yield, while RForest stood out for less complex traits. The high extent of linkage disequilibrium in the population suggests that the marker density employed (approximately one SNP per 60 kb) is enough for the practice of genomic selection in populations with similar genetic structure. In the third chapter, the objective was to extend a class of HBLUP models based on reaction norm, in context of multi-environmental trials with genotype x environment interaction, for accommodation of hybrid genetic relationship and information of the assessed environments. The accuracy of alternative models for multi-environmental predictions was evaluated, as well as the relative importance of structures of additive and multiplicative components, using genetic relationship information and environmental covariates. This strategy allowed to evaluate the influence of different approaches to group the genetic-environmental information on the accuracy of models for prediction of breeding value of progenies for agronomic traits. The data consisted of the same ten trial of S1:3 progenies, carried out during three recurrent selection cycles. Six predictive HBLUP models of reaction norm were considered, using genetic and environmental covariates, as well as interactions between these effects. Genomic information was derived from SNP markers obtained for the 174 progenies of the third selection cycle. The 401 environmental covariates, the genetic information (hybrid genetic relationship) and the interactions among these effects explained an important portion of the phenotypic variance, allowing an increase in the predictive accuracy of models. The use of genetic information and environmental covariates only from the respective selection cycle is enough for accurate predictions of unphenotyped progenies, even in non-sampled environments. This is the first study to take into account simultaneously hybrid genetic relationship, stemming from pedigree information plus SNP markers, and environmental covariates in multi-environmental models based on reaction norm for breeding value prediction in target environments of a recurrent selection program. / A obtenção de ganhos genéticos para caracteres quantitativos associada à manutenção da variabilidade genética são fatores importantes em programas de seleção recorrente. Com os avanços no campo da estatística genômica, estratégias de seleção potencialmente mais rápidas para alcance de ganhos genéticos estão sendo desenvolvidas, como a seleção genômica. Partindo-se de uma população subtropical de arroz irrigado (CNA12S), conduzida durante três ciclos de seleção recorrente, este estudo teve como objetivo geral avaliar o potencial de emprego do esquema de seleção recorrente genômica (GRS) em programas de melhoramento genético de arroz. Três estudos específicos foram desenvolvidos. No primeiro deles, avaliou-se a eficiência do esquema de seleção recorrente genotípica (RS) utilizado no programa de melhoramento de arroz da Embrapa, na obtenção de ganhos genéticos e manutenção da variabilidade genética populacional. O material experimental utilizado constituiu-se de dez ensaios de rendimento de progênies S1:3 associadas a cada ciclo de seleção. Os caracteres avaliados foram produtividade de grãos, altura de planta e número de dias até o florescimento. Componentes de variância e covariância foram obtidos via abordagem Bayesiana e, com uso de marcadores SNP (single nucleotide polymorphisms) associados às progênies, também a diversidade e a estrutura genética populacional. Médias ajustadas de progênies em cada ciclo foram computadas e, por regressão linear generalizada, estimou-se o progresso genético, via abordagem frequentista. As magnitudes do tamanho efetivo populacional e da variância genética indicaram manutenção da variabilidade genética ao longo dos ciclos de seleção. O progresso genético alcançado para produtividade de grãos foi de 760 kg ha-1 por ciclo (1,95 % ao ano) e para dias para florescimento, -6,3 dias por ciclo (-1,28 % ao ano). Concluiu-se que, o progresso genético já alcançado e a variabilidade genética disponível na população demonstram a eficiência de RS no melhoramento de populações de arroz. Num segundo estudo, no contexto de seleção genômica, avaliou-se a eficiência relativa de GRS sobre o esquema de RS; além da acurácia de diferentes modelos de predição genômica, buscando-se propor um esquema de GRS para melhoramento populacional de espécies autógamas como o arroz. Nesse estudo, o material genético foi composto por um ensaio de rendimento de progênies S1:3 do terceiro ciclo de seleção. Do grupo de 196 progênies fenotipadas para oito caracteres, com herdabilidades e arquiteturas genéticas diferentes, um grupo de 174 progênies foi genotipado para marcadores SNP. Dez modelos preditivos foram ajustados ao conjunto de dados. O esquema de GRS, quando comparado ao de RS, apresentou maior eficiência, sobretudo em ganho genético por unidade de tempo. Dos modelos preditivos avaliados, HBLUP (hybrid best linear unbiased prediction, com uso de matriz híbrida de parentesco baseada em pedigree e marcadores SNP) e RForest (random forest) apresentaram maior potencial para predição genômica, haja vista a elevada acurácia de suas predições para maior número de caracteres. O modelo HBLUP foi notoriamente superior para caracteres mais complexos, como produtividade de grãos, enquanto RForest destacou-se para caracteres menos complexos. A alta extensão do desequilíbrio de ligação na população sugere que a densidade de marcadores empregada (aproximadamente um SNP por 60 kb) é suficiente para a prática de predição genômica em populações com estrutura genética similar. No terceiro estudo buscou-se estender uma classe de modelos preditivos HBLUP baseados em norma de reação (contexto de ensaios multiambientais com interação genótipos × ambientes), para acomodar informações de parentesco e de covariáveis associadas aos ambientes de avaliação. Assim, avaliouse a acurácia preditiva de modelos alternativos para predições multiambientais, bem como a importância relativa de estruturas de componentes aditivos e multiplicativos; além da influência de diferentes abordagens de agrupamento de informações genético-ambientais sobre a acurácia dos modelos. O material genético constituiu-se nos mesmos dez ensaios de rendimento de progênies S1:3, conduzidos durante três ciclos de seleção recorrente. Foi considerada uma sequência de seis modelos preditivos de norma de reação, do tipo HBLUP, com uso de covariáveis genéticas e ambientais, além de interações entre esses efeitos. A informação genômica foi proveniente de marcadores SNP obtidos por genotipagem de 173 progênies do terceiro ciclo de seleção. As covariáveis ambientais (num total de 401), informações genéticas (parentesco híbrido) e as interações entre esses efeitos explicaram importante porção da variância fenotípica, o que possibilitou aumento da acurácia preditiva dos modelos. O emprego de informações genéticas e de covariáveis ambientais apenas do respectivo ciclo de seleção mostrou-se suficiente para predições acuradas do desempenho de progênies não fenotipadas, mesmo em ambientes não amostrados. Este estudo é pioneiro em considerar conjuntamente parentesco híbrido, oriundo de informações de pedigree mais marcadores SNP, e covariáveis ambientais em modelos multiambientais baseados em norma de reação, para predição de valor genético em ambientes-alvo de programas de seleção recorrente.
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Mapeamento de QTLs em múltiplos caracteres e ambientes em cruzamento comercial de cana-de-açucar usando modelos mistos / Multi-trait multi-environment QTL mapping in a sugarcane commercial cross using mixed models

Gabriel Rodrigues Alves Margarido 30 August 2011 (has links)
Dados coletados de experimentos de melhoramento geralmente contêm observações fenotípicas para vários caracteres avaliados em múltiplos ambientes. Especificamente para cana-de-açúcar, medidas repetidas são obtidas para cana-planta e uma ou mais socas. Tal cenário presta-se naturalmente ao uso de modelos mistos para modelagem de variâncias genéticas heterogêneas e correlações entre caracteres, locais e cortes. Essa abordagem também nos permite incluir informações de marcadores moleculares, auxiliando no entendimento da arquitetura genética dos caracteres quantitativos através do mapeamento de QTLs. Este trabalho teve como objetivo detectar QTLs e interação QTL por ambiente pelo método do Mapeamento de Múltiplos Intervalos, o qual também permite a inclusão de epistasia no processo de busca. Nossa população de mapeamento foi composta por 100 indivíduos oriundos de um cruzamento biparental entre os cultivares brasileiros pré-comerciais SP80-180 e SP80-4966, avaliados em duas localidades (Piracicaba e Jaú, SP, Brasil) e três anos (2004 a 2006) para percentual de fibra, conteúdo de sacarose (POL) e toneladas de cana por hectare (TCH). Um mapa genético com 96 grupos de ligação cobrindo 2468,14 cM já estava disponível para esse cruzamento. O modelo fenotípico selecionado conteve matrizes de covariância separadas para caracteres e ambientes, o que resultou em um modelo mais parcimonioso com bom ajuste aos dados. Foram detectados 13 QTLs com efeitos principais e 8 interações epistáticas, cada um deles exibindo interação QTL por local, QTL por corte ou a interação tripla. Assim, nenhum QTL apresentou efeitos estáveis ao longo de todas as combinações de ambientes. No total, 13 dos 21 efeitos apresentaram algum grau de pleiotropia, afetando pelo menos dois dos três caracteres. Além disso, esses QTLs sempre afetaram os caracteres fibra e TCH na mesma direção, enquanto que POL foi afetado no sentido oposto. Não foi observada evidência em favor da hipótese de QTLs ligados em detrimento da hipótese de QTL pleiotrópico para qualquer das posições genômicas detectadas. Esses resultados fornecem valiosas informações sobre a base genética da variação quantitativa em cana-de-açúcar e sobre a relação genética entre caracteres. / Data collected from breeding trials usually comprise phenotypic observations for various traits evaluated at multiple test environments. Specifically for sugarcane, repeated measures are obtained for plant crop and one or more ratoons. Such scenario naturally lends itself to the use of mixed models for modeling heterogeneous genetic variances and correlations between traits, locations and harvests. This modeling approach also enables us to include molecular marker information, aiding in understanding the genetic architecture of quantitative traits through QTL mapping. Our work was aimed at detecting QTL and QTL by environment interaction by the Multiple Interval Mapping method, which also allows the inclusion of epistasis in the search process. Our mapping population was composed of 100 individuals derived from a biparental cross between the Brazilian pre-commercial cultivars SP80-180 and SP80-4966, evaluated at two locations (Piracicaba and Jaú, SP, Brazil) and three harvest years (2004 through 2006) for fiber content, sugar content (POL) and tonnes of cane per hectare (TCH). A genetic linkage map with 96 linkage groups covering 2468.14 cM was already available for this cross. The selected phenotypic model contained separate covariance matrices for traits and environments, which resulted in a more parsimonious model with good fit to the data. We detected 13 QTL with main effects and 8 epistatic interactions, each exhibiting QTL by location, QTL by harvest or the three-way interaction. Thus, no QTL displayed stable effects across all environment combinations. Overall, 13 of the 21 effects presented some degree of pleiotropy, affecting at least two of the three traits. Furthermore, these QTL always affected fiber and TCH in the same direction, while POL was affected in the opposite way. There was no evidence in favor of the linked QTL over the pleiotropic QTL hypothesis for any of the detected genome positions. These results give valuable insights about the genetic basis of quantitative variation in sugarcane and about the genetic relation between traits.
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Etude de la variabilité génétique et de la plasticité phénotypique de la vulnérabilité à la cavitation chez Fagus sylvatica L. / Study of genetic variability and genetic plasticity of vulnerability to cavitation in Fagus sylvatica L.

Wortemann, Rémi 16 December 2011 (has links)
Cette thèse visait à étudier la variabilité génétique et plasticité phénotypique de la vulnérabilité à la cavitation chez le hêtre (Fagus sylvatica L.). A cette fin, nous avons tout d’abord testé les variations dues à la méthodologie de mesure de la vulnérabilité à la cavitation. Notre étude a montré que les variations de vulnérabilité à la cavitation au cours du temps sont faibles. Néanmoins, il est préférable d’éviter de récolter les échantillons durant le début de la période de formation du bois. Par ailleurs il est possible de conserver au frais les échantillons sans dégrader les mesures durant au moins un mois. Nos résultats montrent également que la vulnérabilité à la cavitation peut être variable aussi bien au sein d’un même arbre qu’entre populations in situ. Ensuite, nous avons voulu déterminer la part de plasticité phénotypique de la part de variabilité génétique dans la variabilité de la vulnérabilité à la cavitation. Pour cela nous avons étudié 17 populations de hêtre venant de toute l’Europe et poussant dans une plantation comparative. Parmi les 17 populations 6 d’entre elles ont été étudiées dans trois plantations comparatives différentes (France, Espagne et Slovaquie). Nos résultats indiquent que chez le hêtre la vulnérabilité à la cavitation varie considérablement au sein de chaque population. Ils indiquent également que l’on observe peu de différenciation génétique entre populations. Les résultats montrent également que la plasticité phénotypique de la vulnérabilité à la cavitation est importante entre les plantations, et que le degré de cette plasticité peut varier d’une population à l’autre. Pour finir, nous avons regardé s’il existait des relations entre la vulnérabilité à la cavitation et des paramètres d’efficience hydraulique ainsi qu’avec l’efficience d’utilisation de l’eau. Nos résultats ne permettent pas de mettre en évidence des preuves d’un trade-off entre l’efficience et la sureté du xylème. / This work aimed at studying the genetic variability and the phenotypic plasticity of vulnerability to cavitation in beech (Fagus sylvatica L.). We tested the variations due to the methodology of measuring vulnerability to cavitation. Our study showed that the variations in vulnerability to cavitation over time are low. However, it’s better to avoid collecting samples during the period of initial wood formation. Furthermore it’s possible to store samples without degrading measures for during one month. Our results also show that vulnerability to cavitation can be variable both within the same tree and between populations in situ. We determined the proportion of phenotypic plasticity and the proportion of genetic variability in the variability of vulnerability to cavitation. For this we studied 17 beech populations from all Europe and growing in a common garden. Among the 17 populations 6 of them have been studied in three different common gardens (France, Spain and Slovakia). Our results indicate that for beech, vulnerability to cavitation varies considerably within populations. They also indicate that there are few genetic differentiations between populations. The results show that the phenotypic plasticity of vulnerability to cavitation is important among common garden, and the degree of this plasticity can vary between populations. To complete our study, we looked at the relationships between vulnerability to cavitation and hydraulic efficiency parameters and with the water use efficiency. Our results do not reveal evidence of relationships vulnerability to cavitation and other physiological traits.
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Effets de la contrainte hydrique, seule ou en interaction avec un pathogène, sur le fonctionnement de la plante et la qualité du fruit de Solanum lycopersicum L., en fonction du génotype / Effects of water stress, only or in interaction with a pathogen, on plant functioning and fruit quality, depending on genetic variation

Ripoll, Julie 21 April 2015 (has links)
En horticulture, les effets négatifs du déficit hydrique (WD) sur le rendement peuvent être en partie compensés par des effets positifs sur la qualité des fruits et la stimulation des défenses de la plante face à d’autres stress. L'objectif de la thèse était d'explorer un certain nombre de pistes permettant d'évaluer les effets positifs et négatifs du WD, et d'appréhender les facteurs de variations. Après avoir établi un état des connaissances actuelles des effets du WD sur la qualité des fruits, plusieurs questions ont été abordées: 1) quels sont les effets de WD appliqués à des stades précis du développement de la plante ou du fruit, 2) existe-t-il une mémoire du stress en cas d’alternance de période de WD et de récupération, 3) les défenses de la plante sont-elles stimulées par un WD lors d'une infection par un pathogène, et enfin 4) quelle est la variabilité génétique associée aux réponses au WD au travers des objectifs précédents. Pour cela, plusieurs expérimentations ont été réalisées en serres et en phytotrons. Les parents de la population MAGIC de la tomate (ayant une forte variabilité allélique) ont été étudiés, ainsi que deux tomates commerciales (pour l’étude de l’interaction WD – Botrytis cinerea). Les mécanismes de réponses induits lors du WD ont été caractérisés aux stades végétatif et reproductif à l’échelle de la plante, puis lors des phases de développement du fruit (division cellulaire, expansion cellulaire et maturation). Les stades végétatif et reproductif se distinguent par les mécanismes de gestion du stress oxydatif engendré par le WD. Les plantes végétatives seraient plus affectées au niveau des photosystèmes II alors que les plantes reproductives modulent plutôt leur besoin en eau et sont plus sensibles à l’approche des photosystèmes I. L’impact du WD sur la qualité des fruits diffère en fonction de leurs phases de développement. De forts effets génotypes ont été observés avec une amélioration de la qualité dite gustative (par rapport aux teneurs en sucres et acides) pour un génotype dont les caractéristiques initiales étaient plus faibles que le second génotype testé. L’alternance de périodes de WD et de récupérations constitue un bon compromis entre économie d’eau et adaptation des plantes (via une bonne gestion du stress oxydatif). Cette alternance de stress a des effets neutres à positifs sur les teneurs en sucres des fruits en fonction des génotypes et des réponses très variables pour les teneurs en acides organiques, caroténoïdes et acide ascorbique en fonction des génotypes. L’interaction entre un WD et B. cinerea génère une diminution du ratio C/N associé à une stimulation des défenses de la plante. Cependant l'interaction favorise le développement du pathogène dans les tiges. Cet effet délétère de l'interaction semble lié aux régulations hormonales mises en jeu avec la stimulation de l'ABA (par le WD) et de la voie SA (par B. cinerea et indirectement par le WD) qui sont antagonistes aux voies JA/ET de réponse aux pathogènes nécrotrophes. Toutefois, un effet positif a été observé pour les infections sur feuilles détachées qui constituent un instantané des défenses de la plante, et ce, uniquement pour les plantes déjà infectées sur tige. Ces résultats suscitent de nouvelles interrogations sur la stimulation des défenses de la plante. Ainsi, le WD permet une augmentation du pool de sucres solubles, sans impact notable sur le rendement, avec des effets variables sur les composés secondaires. Le WD permet également dans une certaine mesure de stimuler les défenses de la plante mais de nouvelles recherches sont nécessaires. Enfin, la variabilité génétique des réponses à l’échelle de la plante et du fruit est importante et interagit avec le WD. / In horticulture, yield losses associated to water deficit (WD) could be compensated by positive effects on fruit quality and stimulation of plant to others stresses. The aim of the thesis was to explore a number of questions to assess the positive and negative effects of the WD, and to understand factors variations after setting a current knowledge of the effects of WD quality fruit. The questions were: 1) to characterize the effects of WD applied at specific stages of development of plant or fruit, 2) to understand the stress memory effect by alternating period of WD and recovery, 3) to test the stimulation of plant defences by WD during an infection by a pathogen, and 4) to study the genetic variability associated with responses to WD through the previous objectives. For this, several experiments were conducted in greenhouses and growth chambers. The parents of the MAGIC population of tomato (with rich allelic variability) were studied, as well as two commercial tomatoes (for the study of the interaction between WD and Botrytis cinerea). Plant response mechanisms induced during a WD were characterized in both plant vegetative and reproductive stages, and then during the fruit development stages (cell division, cell expansion and maturation). The plant vegetative and reproductive stages are distinguished by different mechanisms of oxidative stress management generated by WD. Vegetative plants are more affected at the photosystem II while reproductive plants rather modulate their water needs and responses at the photosystem I. The impact of WD on fruit quality differs according to fruit developmental stages. Strong genotypes effects were observed with an important increase in fruit taste quality (according to the concentrations in sugars and acids) for one genotype, which had poorer initial fruit quality than the second. Alternating periods of WD and recovery is a good compromise between water saving and plant adaptation (through proper management of oxidative stress). This alternation of stress has neutral to positive effects on fruit sugar content according to the genotypes and highly variable responses for contents of organic acids, carotenoids and ascorbic acid according to the genotypes. The interaction between a WD and B. cinerea generates a decrease of C/N ratio that can be associated to a stimulation of the pool of plant defence. However, the interaction between B. Cinerea and this WD promote pathogen development in stems. This deleterious effect of interaction seems attributable to hormonal regulation with the stimulation of the ABA pathway (by WD) and the SA pathway (by B. cinerea), which are antagonistic to the JA / ET pathway involved in response to necrotroph pathogens. However, a positive effect was observed for infections in detached leaves of infected plants, detached leaves represent a snapshot of plant defences and these results raise new questions. Overall, these data provide that WD improve fruit taste (sugars and acids) without yield losses but had variables effects on health promoting compounds. WD could permit the stimulation of plant defence but more research is needed. To finish, the genetic variability induced important variability in plant and fruit responses and interact with WD.
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Bases génétiques de la croissance hétérotrophe de l'hypocotyle en conditions optimales et sous stress abiotiques chez Medicago truncatula : contribution du nombre et de la longueur des cellules / Genetic bases of the heterotrophic growth of hypocotyl in optimal conditions and under abiotic stresses in Medicago truncatula : contribution of the number and length of the cells

Youssef, Chvan 15 October 2015 (has links)
La croissance hétérotrophe de l’hypocotyle est une étape clé pour la réussite de la levée. La présente étude est focalisée sur le déterminisme génétique de l’allongement de cet organe à l’obscurité chez Medicago truncatula en analysant le nombre et la longueur des cellules de l’épiderme, tissu gouvernant l’allongement des organes. Une grande variabilité génétique du nombre de cellules a été révélée dans les graines de 15 génotypes représentatifs de la diversité génétique de l’espèce. La stabilité de ce caractère dans des graines provenant de différentes productions suggère qu’il est sous contrôle génétique fort. Il a été montré que ce nombre de cellules, préétabli dans les graines, est le principal déterminant de la variation génotypique de la longueur de hypocotyle en conditions optimales de croissance. Par contre, l'élongation cellulaire devient le déterminant majeur des différences génotypiques observées sous stress abiotiques (basse température, déficit hydrique).Des loci contrôlant le nombre de cellules de l’épiderme et leur longueur maximale à basse température ont ensuite été identifiés dans une population de lignées recombinantes. Ceux ayant un impact sur l’élongation de l’hypocotyle à basse température ont été mis en évidence. Enfin, deux génotypes présentant un nombre de cellules similaire mais des capacités d’allongement cellulaire contrastées ont été plus finement comparés. Des protéines ayant un rôle dans la formation et l’organisation du cytosquelette et dans la modification des parois cellulaires ont été révélées en lien avec les différences d’allongeme / The heterotrophic growth of hypocotyl is a crucial process for successful seedling emergence. The present study is focused on the genetic determinism of its elongation in darkness in Medicago truncatula by analyzing the number and the length of cells of epidermis, the tissue controlling organ elongation.A large genetic variability of the epidermal cell number of the hypocotyl in seeds of 15 genotypes representative of the genetic diversity of the species was revealed. The stability of this trait in the seeds collected from different productions suggests it is under strong genetic control. This cell number was shown to be the main contributor of genotypic variation of hypocotyl length in optimal conditions. On the other hand, cell elongation becomes the major determinant of the genotypic differences observed under abiotic stresses (low temperature, water deficit).Quantitative Trait Loci (QTLs) controlling the number of epidermal cells and their maximal length at low temperature were then identified using a recombinant inbred lines population, and those impacting hypocotyl elongation at low temperature were highlighted.Finally, two genotypes sharing a similar cell number but contrasted capacities of cell elongation were compared more in detail. Proteins playing a role in the formation and organization of cytoskeleton and in the modification of the cell wall were revealed in connection with the differences in cellular elongation between genotypes. Moreover, differences in the cell wall sugar composition, in the degree of methylation of pectins and in a potential inhibito
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Analýza primárních fotosyntetických procesů u jehličnanů: srovnání vybraných metod a možné využití při studiu genetické variability / Analysis of primary photosynthetic processes in conifers: A comparison of selected methods and their possible utilisation for the study of genetic variability

Palovská, Markéta January 2015 (has links)
Conifers are important both ecologically and socioeconomically, however, same parts of their biology are not that well researched. This includes genetics and breeding and partly even physiology. Because quantitative genetic analyzes applied in breeding necessitate an analysis of a large number of samples, and conventional methods of analysis are quite time-consuming, certain parameters describing e.g. the activity of photosynthetic electron-transport chain (ETC) are considered for such use. Several methods of the measurement of the activity of photosynthetic ETC exist, but there are some problems with their usage in conifers. I studied this issue from different points of view in three parts of this thesis. 1) I compared the photosynthetic ETC activity in 8 species of conifers using chlorophyll (Chl) fluorescence measurements on intact needles and polarographic measurements in isolated chloroplasts. Each method brought different information. 2) I measured Chl fluorescence parameters, reflectance spectra and pigment content in 536 genetically defined trees of Pinus sylvestris L. Many parameters showed relatively high genetic variability and heritability. I have also determined the suitability of various reflectance indices to estimate pigment and water content of needles. 3) I have optimized the...

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