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Análise da interação genótipo X ambiente assistida por marcadores moleculares em milho (Zea mays L.).; Genotipe x environment interaction analysis assisted by molecular markers in maize (Zea mays L.).

Rumin, Glauce Cristina Ricardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/05/2005 Português
Relevância na Pesquisa
65.98%
A produtividade de grãos em milho é um caráter altamente complexo e muito dependente das condições ambientais. Neste trabalho de pesquisa, buscouse identificar regiões cromossômicas relacionadas à produtividade de grãos em milho por meio de análises de regressão múltipla stepwise, em vários ambientes. Os dados genotípicos advém da genotipagem de linhagens S2 por 163 locos RFLP, enquanto os dados fenotípicos foram obtidos de experimentos com repetições instalados em 11 locais distintos, nos quais foram avaliados os topcrosses das linhagens com quatro testadores diferentes. Foram selecionadas marcas associadas ao caráter nos diferentes ambientes, posteriormente comparadas a fim de verificar a consistência na expressão de genes das regiões detectadas. De maneira geral, observou-se que a maioria delas é ambiente-específica. Após a seleção das marcas, foi aplicado um índice de seleção de linhagens, baseado nos valores bj da regressão múltipla. O índice é composto pelo valor próprio das linhagens em topcrosses e por uma medida da complementaridade genotípica entre linhagens. As melhores linhagens, segundo o índice de seleção, foram agrupadas por testador e verificouse que a coincidência de linhagens entre locais variou de 48...

Interação genótipo x ambiente via correlações genéticas entre rebanhos e normas de reação utilizando abordagem bayesiana em bovinos de corte; Genotype by environment interaction using genetic correlations between herds and reaction norms under bayesian approach in beef cattle

Ribeiro, Sandra
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/03/2010 Português
Relevância na Pesquisa
65.94%
O presente estudo teve por objetivo estudar os efeitos da interação genótipo x ambiente sobre as características peso à desmama, peso ao sobreano e ganho de peso da desmama ao sobreano em bovinos da raça Nelore. Foram analisados 58.032 registros de peso à desmama ajustados para 205 dias (PD), 46.032 registros de peso ao sobreano ajustados para 550 dias (PS) e 45.844 registros de ganho de peso da desmama ao sobreano ajustados para 345 dias (GP), originários de três rebanhos distintos. Os dados foram submetidos a dois métodos de análises: no primeiro, processaram-se análises unicaracterísticas para os rebanhos individuais e para o conjunto formado pelos três rebanhos, e análises tri-características para os dados de cada rebanho, em que as mesmas características foram consideradas como variáveis distintas. Foi utilizado o programa GIBBS2F90, sob abordagem bayesiana. As estimativas dadas pelas médias dos coeficientes de herdabilidade para PD, PS e GP variaram de 0,09 a 0,24, 0,24 a 0,44 e 0,09 a 0,31, respectivamente. Nesta mesma ordem, as correlações genéticas das mesmas características nos diferentes ambientes variaram de 0,88 a 0,93, 0,85 a 0,98 e 0,75 a 0,97. As correlações entre as DEPs dos touros nos ambientes variaram de 0...

Interação QTL por ambientes para produção de grãos e seus componentes em uma população de milho tropical; QTL by environment interaction for grain yield and its components in a tropical maize population

Barrios, Sanzio Carvalho Lima
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 06/12/2010 Português
Relevância na Pesquisa
56%
A interação QTL por ambientes (QE) têm sido relatada como uma das principais causas de insucesso da seleção assistida por marcadores moleculares (SAM). Estudos que visam o melhor entendimento da interação QE podem contribuir para o aumento da eficiência dos programas de SAM. O objetivo deste trabalho foi mapear QTL para produção de grãos (PG), prolificidade (PROL), peso de 500 grãos (P500), comprimento (CE) e diâmetro de espiga (DE), profundidade de grão (PROF), número de fileiras (NFil) e de grãos por fileira (NGFil) em uma população de milho tropical, verificar a importância da interação QE para estes caracteres e avaliar a estabilidade dos efeitos genéticos dos QTL mapeados. Uma população de 256 progênies F2:3 obtida do cruzamento entre duas linhagens de grupos heteróticos distintos e contrastantes para diversos caracteres foi avaliada em 13 ambientes. Os ambientes foram alocados em grupo de ambientes utilizando um método de agrupamento e o modelo AMMI, sendo que ambos os métodos levaram a identificação de três grupos de ambientes. O mapeamento de QTL foi realizado considerando um mapa genético com 177 marcadores microssatélites e mapeamento por intervalo composto expandido para múltiplos ambientes (mCIM). As médias de grupo de ambientes para cada caráter foram utilizadas nas análises. Foram mapeados 87 QTL...

Interação genótipo-ambiente em bovinos de corte compostos; Genotype-environment interaction in composite beef cattle

Santana Júnior, Mário Luiz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/07/2011 Português
Relevância na Pesquisa
65.96%
Objetivou-se com o presente estudo foram caracterizar e definir ambientes homogêneos de produção de bovinos de corte compostos no Brasil com relação às variáveis climáticas e geográficas, utilizando técnicas exploratórias multivariadas. Verificar a presença de interação genótipo-ambiente (GxE) nas características peso ao nascimento (PN), peso a desmama (PD), ganho de peso da desmama ao sobreano (GP), perímetro escrotal (PE) e musculosidade (MUS). Pela análise de agrupamento não-hierárquico foram agrupadas as regiões similares com relação às variáveis ambientais. Foram formados seis grupos de fazendas. A inclusão do efeito de interação touro-grupo foi avaliada em análises uni-característica. Comparou-se um modelo com o efeito de interação touro-grupo com outro sem esse efeito. Incluir o efeito de interação touro-GEO no modelo de avaliação genética do PN, PD e PE não resultou melhor ajuste aos dados, no entanto não deve ser descartada a hipótese de se considerar outros tipos de efeitos de GxE. Foram estimados parâmetros genéticos por meio de análises multi-característica, considerando-se a mesma característica como diferente em cada grupo de fazendas. Foi verificada heterogeneidade de variância para todas as características. Os coeficientes de herdabilidade nos grupos de fazendas para PN...

Distribuição empírica dos autovalores associados à matriz de interação dos modelos AMMI pelo método bootstrap não-paramétrico; Empirical distribution of eigenvalues associated with the interaction matrix of the AMMI models for non-parametric bootstrap method

Hongyu, Kuang
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/01/2012 Português
Relevância na Pesquisa
56.04%
A interação genótipos ambientes (G E) foi definido por Shelbourne (1972) como sendo a variação entre genótipos em resposta a diferentes condições ambientais. Sua magnitude na expressão fenotípica do caráter pode reduzir a correlação entre fenótipo e genótipo, in acionando a variância genética e, por sua vez, parâmetros dependentes desta, como herdabilidade e ganho genético com a seleção. Estudos sobre a adaptabilidade e a estabilidade fenotípica permitem particularizar os efeitos da interação GE ao nível de genótipo e ambiente, identificando a contribuição relativa de cada um para a interação total. Varias metodologias estatísticas têm sido propostas para a interpretação da interação G E proveniente de um grupo de cultivares testados em vários ambientes. Entre essas metodologias destaca-se os modelos AMMI (Additive Main Eects and Multiplicative Interaction Model), que vem ganhando grande aplicabilidade nos últimos anos. O modelo AMMI e um método uni-multivariado, que engloba uma analise de variância para os efeitos principais, que são os efeitos dos genótipos (G) e os ambientes (E) e para os efeitos multiplicativos (interação genótipo ambiente), para a qual utiliza-se a decomposição em valor singular (DVS). Essa técnica multivariada baseia-se no uso dos autovalores e autovetores provenientes da matriz de interação G E. Araujo e Dias (2005) verificaram o problema de superestimação e subestimação de autovalores estimados da maneira convencional. Efron(1979) propôs uma técnica de simulação numérica chamada Bootstrap para avaliar tais incertezas. O método Bootstrap consiste em uma técnica de reamostragem que permite aproximar a distribuição de uma função das observações a partir da distribuição empírica dos dados. Por meio desse método...

Effects of sex and age on genotype x environment interaction for beef cattle body weight studied using reaction norm models

Pegolo, N. T.; Albuquerque, Lucia Galvão de; Lobo, R. B.; Oliveira, Henrique Nunes de
Fonte: Amer Soc Animal Science Publicador: Amer Soc Animal Science
Tipo: Artigo de Revista Científica Formato: 3410-3425
Português
Relevância na Pesquisa
65.96%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The interest in the effect of genotype x environment interaction is increasing because animal breeding programs have become geographically broader. Climate changes in the next decades are also expected to challenge the present breeding goals, increasing the importance of environmental sensitivity. The aim of this work was to analyze genotype x environment interaction effect on cattle BW using the environmental sensitivity predicted by random regression reaction norm models, including sex and age effects as additional dimensions in the study. Genetic parameters were estimated for adjusted BW of Brazilian Nelore cattle at different ages (120, 210, 365, and 450 d), using linear polynomials for random regression analysis. The analyses with sex as a fixed effect (total analyses) were compared with those with sex-separated progenies (male and female progeny analyses, respectively). (Co)variance components were estimated and breeding values calculated EPD. The results showed important differences in reaction norm model genetic parameter estimates according to different age and sex analyses. The results confirmed the presence of an important genotype x environment x sex x age interaction for Nelore cattle BW. The patterns in these results lead to a revision of the importance of sexual and developmental factors on plasticity and adaptation concepts.

Genotype x environment interaction for age at first calving in Brazilian and Colombian Holsteins

Cerón-Muñoz, M. F.; Tonhati, Humberto; Costa, C. N.; Maldonado-Estrada, J.; Rojas-Sarmiento, D.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 2455-2458
Português
Relevância na Pesquisa
55.96%
The objective was to determine whether there is a genotype x environment interaction for age at first calving (AFC) in Holstein cattle in Brazil and Colombia. Data included 51,239 and 25,569 first-lactation records from Brazil and Colombia, respectively. Of 4230 sires in the data, 530 were North American sires used in both countries. Analyses were done using the REML bi-trait animal model, and AFC was considered as a distinct characteristic in each country. Fixed effects of contemporary group (herd-calving year), sire genetic group, and cow genetic group, and random effects of animal and residual variation were included in the model. Average AFC in Brazil and Colombia were 29.5 ± 4.0 and 32.1 ± 3.5 mo, respectively. Additive and residual genetic components and heritability coefficient for AFC in Brazil were 2.21 mo 2, 9.41 mo 2, and 0.19, respectively, whereas for Colombia, they were 1.02 mo 2, 6.84 mo 2, and 0.13, respectively. The genetic correlation of AFC between Brazil and Colombia was 0.78, indicating differences in ranking of sires consistent with a genotype x environment interaction. Therefore, in countries with differing environments, progeny of Holstein sires may calve at relatively younger or older ages compared with contemporary herdmates in one environment versus another.

Buffalo milk production in brazil and colombia: Genotype by environment interaction

Hurtado-Lugo, Naudin; Cerón-Muñoz, Mario; Aspilcueta-Borquis, Raul; Sesana, Roberta; de Albuquerque, Lucia Galvão; Tonhati, Humberto
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.96%
The objective of this study was to determine whether there is a genotype by environment interaction (GxE) for dairy buffaloes in Brazil and Colombia. The (co)variance components were estimated by using a bi-trait repeatability animal model with the REML method. Each trait consisted in the milk yield obtained in both countries. Contemporary group (herd, year and season of parity) and age at parity (linear and quadratic covariate) fixed effects, along with the additive genetic, permanent environment, and the residual random effects were included in the model. Genetic, permanent environmental and residual variance and heritabilities were different for both countries. The genetic correlations for milk yield between Brazil and Colombia were low (between 0.10 and 0.13), indicating a GxE interaction between both countries. Knowing that this interaction influences the genetic progress of buffalo populations in Brazil and Colombia, we recommend choosing sires tested in the country they will be used, along with conducting joint genetic evaluations that consider GxE interaction effects.

Genotype×production environment interaction for weaning weight in Angus populations of Brazil and Uruguay

Espasandin, A. C.; Urioste, J. I.; Naya, H.; Alencar, M. M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 264-270
Português
Relevância na Pesquisa
65.89%
The objective of this study was to define production environments by grouping different environmental factors and, consequently, to assess genotype by production environment interactions on weaning weight (WW) in the Angus populations of Brazil and Uruguay. Climatic conditions were represented by monthly temperature means (°C), minimum and maximum temperatures in winter and summer respectively and accumulated rainfall (mm/year). Mode in month of birth and weaning, and calf weight (kg) and age (days) at weaning were used as indicators of management conditions of 33 and 161 herds in 13 and 34 regions in Uruguay and Brazil, respectively. Two approaches were developed: (a) a bi-character analysis of extreme sub-datasets within each environmental factor (bottom and top 33% of regions), (b) three different production environments (including farms from both countries) were defined in a cluster analysis using standardized environmental factors. To identify the variables that influenced the cluster formation, a discriminant analysis was previously carried out. Management (month, age and weight at weaning) and climatic factors (accumulated rainfalls and winter and summer temperatures) were the most important factors in the clustering of farms. Bi or trivariate analyses were performed to estimate heritability and genetic correlations for WW in extreme sub-datasets within environmental factor or between clusters...

Genotype by environment interaction for post-weaning weight gain, scrotal circumference, and muscling score of composite beef cattle in different regions of Brazil

Santana, M. L.; Eler, J. P.; Cardoso, F. F.; Albuquerque, L. G.; Balieiro, J. C. C.; Pereira, R. J.; Ferraz, J. B. S.
Fonte: Funpec-editora Publicador: Funpec-editora
Tipo: Artigo de Revista Científica Formato: 3048-3059
Português
Relevância na Pesquisa
65.91%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 09/05072-4; The objectives of this study were to characterize and define homogenous production environments of composite beef cattle in Brazil in terms of climatic and geographic variables by using multivariate exploratory techniques; to evaluate the presence of genotype by environment interaction (GxE) for post-weaning weight gain (PWG), yearling scrotal circumference (SC), and yearling muscling (MUS). Hierarchical and nonhierarchical cluster analysis was used to group farms located in regions with similar environmental variables into clusters. Six clusters of farms were formed. The effect of sire-cluster interaction was tested by single-trait analysis. Genetic parameters were estimated by multi-trait analysis considering the same trait to be different in each cluster. The effect of sire-cluster interaction was significant (P <0.01) for PWG and MUS. Estimates of genetic correlations among clusters ranged from 0.31 to 0.93 for PWG, 0.64 to 0.89 for SC, and 0.18 to 0.80 for MUS. These results indicate the need for a genetic analysis on a regional basis or inclusion of the GxE effect in the statistical model to permit appropriate evaluation of the animals.

New strategies to detect and understand genotype-by-environment interactions and QTL-by-environment interactions

Rodrigues, Paulo Jorge Canas
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Tese de Doutorado
Publicado em //2012 Português
Relevância na Pesquisa
55.98%
Dissertação para obtenção do Grau de Doutor em Estatística e Gestão do Risco, especialidade em Estatística; Genotype-by-environment interaction (GEI) is frequent in multi-environment trials, and represents differential responses of genotypes across environments. With the development of molecular markers and mapping techniques, researchers can go one step further and analyse the whole genome to detect specific locations of genes which influence a quantitative trait such as yield. These locations are called quantitative trait locus (QTL), and when these QTLs have different expression across environments we talk about QTLby-environment interactions (QEI), which is the base of GEI. Good understandings of these interactions enable researchers to select better genotypes across different environmental conditions and, consequently, to improve crops in developed and developing countries. In this thesis I intend to present new strategies to improve detection and better understanding of QTLs, especially those exhibiting QEI in the context of multi-environment trials, by using and providing open source software. The first part of this thesis presents a comparison between two of the most used methods to analyse and to structure GEI: the joint regression analysis (JRA) and the additive main effects and multiplicative interaction (AMMI) model. This comparison is made in terms of “robustness” with different incidence rates of missing values...

Natural selection and family X location interaction in the common (dry) bean plant

Pirola,Luís Henrique; Ramalho,Magno Antonio Patto; Carneiro,José Eustáquio S.; Abreu,Ângela de Fátima Barbosa
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 Português
Relevância na Pesquisa
55.89%
Natural selection takes place while advancing generations of segregant populations of self pollinating species by the population (bulk) method. There is evidence that it maintains the individuals with greater grain yield. The question arises whether natural selection preserves the individuals which are more adapted only to the environment where the generation advance occurred, that is, if it contributes to increasing the genotype x environment interaction in the family assessment. This study was carried out to check this hypothesis in the common bean plant using families derived from a segregating population from a cross between the Carioca MG x ESAL 686 cultivars. The segregating populations increase in homozygosity was obtained by the population (bulk) method until the F14 generation, in three distinct locations in Minas Gerais state: Lavras, Lambari and Patos de Minas. Forty-seven F14:15 families were randomly taken from the population in each location and later multiplied to obtain F14:16 families. These families were jointly assessed with three controls using a triple 12 x 12 lattice design in the three locations of generation advance in the wet season of 1998/1999. All the estimated parameters showed that while advancing segregant populations by the population (bulk) method...

Epistasis and genotype-by-environment interaction of grain protein content in durum wheat

Bnejdi,Fethi; Gazzah,Mohamed El
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 Português
Relevância na Pesquisa
65.89%
Parental, F1, F2, BC1 and BC2 generations of four crosses involving four cultivars of durum wheat (Triticum durum Desf.) were evaluated at two sites in Tunisia. A three-parameter model was found inadequate for all cases except crosses Chili x Cocorit 71 at site Sidi Thabet and Inrat 69 x Karim at both sites. In most cases a digenic epistatic model was sufficient to explain variation in generation means. Dominance effects (h) and additive x additive epistasis (i) (when significant) were more important than additive (d) effects and other epistatic components. Considering the genotype-by-environment interaction, the non-interactive model (m, d, h, e) was found adequate. Additive variance was higher than environmental variance in three crosses at both sites. The estimated values of narrow-sense heritability were dependent upon the cross and the sites and were 0%-85%. The results indicate that appropriate choice of environment and selection in later generations would increase grain protein content in durum wheat.

Genotype × country interaction for weaning weight in the Angus populations of Brazil and Uruguay

Espasandin,Ana Carolina; Urioste,Jorge Ignacio; Campos,Leonardo Talavera; Alencar,Maurício Mello de
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 Português
Relevância na Pesquisa
55.94%
It was analyzed the existence of genotype × environment interaction for weaning weight in populations of Angus from Brazil and Uruguay by using records of 73,205 animals (10,257 from Uruguay and 62,948 from Brazil) belonging to 33 and 161 farms and 13 and 34 regions in Uruguay and Brazil, respectively. It was used the one- and two-trait animal model analyses considering weight at weaning of each country as different characters. Coefficients of direct and maternal additive-genetic correlation estimated by two statistical models (including or not bull × country effect) Models included the fixed effects of contemporary group (herd-year and month of birth), sex of the calf, the covariates age of dam at calving (years) and age of calf at weaning (days), and the random effects genetic-additive maternal and direct, maternal permanent environment and residual. Herdabilidades (of direct effect) were similar in both countries and with moderate magnitude (0.35 and 0.15, respectively). Coeficients of correlation among maternal and direct genetic effects between Brazil and Uruguay were 0.77 and 0.13, respectively, and comparison among models (with and without bull × country effect) showed significant differences. Correlations among classifications (ranking of genetic values) of bulls with progenie in both countries ranged from 0.35 to 0.41 for estimations in one- and two-trait models...

Complex interaction between genotypes and growing seasons of carioca common bean in Goiás/Distrito Federal

Pereira,Helton Santos; Melo,Leonardo Cunha; Del Peloso,Maria José; Faria,Luís Cláudio de; Wendland,Adriane
Fonte: Crop Breeding and Applied Biotechnology Publicador: Crop Breeding and Applied Biotechnology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 Português
Relevância na Pesquisa
55.89%
The objectives of this study were to assess the importance of the complex interaction between common bean genotypes and growing seasons in the state of Goiás and the Distrito Federal and verify the need for evaluation and indication of cultivars for each season. Yield data of 16 genotypes in 16 trials conducted in two growing seasons (winter and rainy) were used. The coefficient of determination was estimated in the analyses of variance with decomposition of the genotype x environment interaction. The complex percentage of the interaction was estimated and the Spearman correlation between seasons. Differences were detected between seasons and presence of genotype - season (GS) interaction, with greater significance than the other double interactions with genotypes. The correlations indicated a predominantly complex GS interaction. This predominantly complex nature of the GS interaction calls for an assessment of the genotypes in both seasons, which may however identify cultivars with general adaptation.

Métodos AMMI, GGE BIPLOT, REML/BLUP e análise de fatores na estabilidade e estratificação de ambientes de safrinha para seleção de híbridos de milho; Methods AMMI, GGEbiplot, REML/BLUP, and Factors Analysis on stability and environment stratification of second harvest for selection of maize hybrids

Martinelli, André Paulo
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
Português
Relevância na Pesquisa
56%
O presente estudo foi realizado com objetivos de avaliar os efeitos da interação genótipo x ambiente, adaptabilidade, estabilidade, seleção dos melhores híbridos de milho e estratificar ambientes mais indicados para seleção de genótipos adaptados a safrinha da região Central do Brasil, por meio dos métodos AMMI (Additive Main Effects and Multiplicative Interaction Analysis), GGEbiplot (Genotype and Genotypes by Environment Interaction), AF (Análise de Fatores) e REML/BLUP. Foram utilizados dados da avaliação de produtividade de grãos, provenientes da empresa Dow AgroSciences, referente a 25 híbridos de milho, em 13 locais distribuidos nos estados de Mato Grosso do Sul, Mato Grosso, Goiás e Distrito Federal, em duas safrinhas, 2011 e 2012. Foram realizadas as análises de variância e posteriormente as análises de adaptabilidade e estabilidade. As análises AMMI e GGE biplot associadas aos valores genéticos preditos estimados pela metodologia REML/BLUP permitiram indicação dos melhores híbridos para cultivo em ambientes de safrinha do Brasil Central. Os melhores híbridos para plantio na safrinha no Brasil Central quanto a adaptabilidade e estabilidade foram: H10, H17, H07, H09 e H05. O método REML/BLUP fornece resultados que são interpretados diretamente como valores genotípicos e apresentaram alta coincidência com os dados médios de produtividade de grãos...

Regionaliza????o para o cultivo do feij??o no Rio Grande do Sul com base na intera????o gen??tipo x ambiente.; Common bean cropping regionalization in Rio Grande do Sul State, Brazil, based on genotype x environment interaction.

PIANA, Clause F??tima de Brum
Fonte: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Fitomelhoramento; UFPel; BR Publicador: Universidade Federal de Pelotas; Agronomia; Programa de P??s-Gradua????o em Fitomelhoramento; UFPel; BR
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
56.03%
In Brazil, common bean (Phaseolus vulgaris L.) is cultivated in a range of ecologically differentiated environments. For being a culture highly influenced by the environment variation, its average productivity in the Country is unstable and low. An origin of this variation of productivity is the genotype x environment interaction, which has been one of the largest impediments for obtaining genotypes that maintain consistently high yield in the growing environments. The methods proposed for the exploration of the genotype x environment interaction are directed to the stability of the yield of the genotypes or to the regionalization of the growing locations. Most of the common bean genotypes registered for cultivation in Rio Grande do Sul evidences yield instability. The present research explored data from Rio Grande do Sul Common Bean State Trial ("Ensaio Estadual de Feij??o" - EEF), executed at 24 locations in the period from 1987/88 to 1994/95, with considerable variation of genotypes and locations among those years. This research had two main objectives: (1) to evaluate the magnitude and the nature of the genotype x environment interaction and (2) to identify possible stratification of the growing region of common bean in the State in sub-regions inside of which the genotypes have stable relative performance. The inferences about the components of the interaction genotype x environment were proceeded by the joint analysis of each one of the eight years and the analyses of two subsets of four years and of the set of eight years. Because of the intent of obtaining a long time regionalization...

The analysis of quantitative trait loci in multi-environment trials using a multiplicative mixed model

Verbyla, A.; Eckermann, P.; Thompson, R.; Cullis, B.
Fonte: C S I R O Publishing Publicador: C S I R O Publishing
Tipo: Artigo de Revista Científica
Publicado em //2003 Português
Relevância na Pesquisa
55.93%
A new approach for multi-environment quantitative trait locus (QTL) analysis based on an appropriate genetic model is presented. To accommodate a multi-environment analysis, the size of a QTL effect is assumed to be a random effect. The approach results in a multiplicative mixed model for QTL × environment interaction of the factor analytic type. The full genetic model may also include a factor analytic model for the residual genotype × environment interaction, whereas the environmental model for the non-genetic variation involves local, global, and extraneous variation. The approach is used to determine QTLs for yield in the Arapiles × Franklin doubled haploid population of the National Barley Molecular Marker Program. Analysis leads to the determination of 8 QTLs. Many of these QTLs are associated with other traits.

Genetic dissection of grain yield in bread wheat. II. QTL-by-environment interaction

Kuchel, H.; Williams, K.; Langridge, P.; Eagles, H.; Jefferies, S.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2007 Português
Relevância na Pesquisa
56%
The grain yield of wheat is influenced by genotype, environment and genotype-by-environment interaction. A mapping population consisting of 182 doubled haploid progeny derived from a cross between the southern Australian varieties ‘Trident’ and ‘Molineux’, was used to characterise the interaction of previously mapped grain yield quantitative trait locus (QTL) with specific environmental covariables. Environments (17) used for grain yield assessment were characterised for latitude, rainfall, various temperature-based variables and stripe rust infection severity. The number of days in the growing season in which the maximum temperature exceeded 30°C was identified as the variable with the largest effect on site mean grain yield. However, the greatest QTL-by-environmental covariable interactions were observed with the severity of stripe rust infection. The rust resistance allele at the Lr37/Sr38/Yr17 locus had the greatest positive effect on grain yield when an environment experienced a combination of high-stripe rust infection and cool days. The grain yield QTL, QGyld.agt-4D, showed a very similar QTL-by-environment covariable interaction pattern to the Lr37/Sr38/Yr17 locus, suggesting a possible role in rust resistance or tolerance. Another putative grain yield per se QTL...

Contribution of genome-environment interaction to pre-eclampsia in a Havana Maternity Hospital

Lardoeyt,Roberto; Vargas,Gerardo; Lumpuy,Jairo; García,Ramón; Torres,Yuselis
Fonte: Medical Education Cooperation with Cuba Publicador: Medical Education Cooperation with Cuba
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2013 Português
Relevância na Pesquisa
65.97%
INTRODUCTION: Pre-eclampsia is a major cause of morbidity and mortality during pregnancy worldwide and is among the leading causes of maternal mortality in Cuba. It is a complex, multifactoral disease, in which interaction of genetic and environmental factors should not be overlooked if the goal is proper risk assessment to support personalized preventive genetic counseling and more effective prenatal care to prevent pregnancy complications. OBJECTIVE: Determine the contribution to pre-eclampsia of interaction between a predisposing genome and adverse environmental factors in pregnant women in a Havana maternity hospital. METHODS: This was the exploratory phase of a hospital-based case-control study, using January 2007-December 2009 patient records from the Eusebio Hernández University Hospital, a provincial maternity hospital in Havana. Eighty pregnant women diagnosed with pre-eclampsia and 160 controls were studied. The main variables were age, parity, nutritional status (measured by BMI), alcohol use, tobacco use, and history of pre-eclampsia in relatives of the pregnant woman (proband) or of her partner. Pearson chi square and Fisher exact test were used to assess statistical significance of associations between variables and odds ratio as a measure of association strength. Familial aggregation was studied and a case-control design used to assess gene-environment interaction...