Diversidade genética, adaptabilidade e estabilidade de genótipos de soja no Mato Grosso

• Ano de defesa: 2011
• Autor(a) principal: Boldt, Alberto Souza
• Orientador(a): Sediyama, Tuneo
• Banca de defesa: Sá, Rogério Oliveira de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Glycine max (L.) Merril; Diversidade genética; Adaptabilidade; Estabilidade
• Palavras-chave em Inglês: Glycine max (L.) Merril; Genetic diversity; Adaptability; Stability
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4750

The objectives of this study were (i) to evaluate the magnitude of the genotypic, environmental and genotype- by-environment interaction effects in agronomic, chemical and seed sanity quality traits; (ii) to estimate the adaptability and stability of soybean genotypes for the State of Mato Grosso; and (iii) to quantify the genetic diversity of genotypes based on phenotypic evaluations. Eight trials were carried out under fields conditions in Primavera do Leste, Nova Ubiratã and Pedra Preta, located in Mato Grosso. The trials were established in a randomized block design with four replications. Each plot was formed by a row of four meters in length, spaced 0,70 meters between rows, with a density of 15 seeds per meter. We evaluated 26 soybean genotypes adapted to the state of Mato Grosso, belonging to the Soybean Breeding Program of the Instituto Matogrossense do Algodão (IMAmt) and Bacuri Pesquisa em Agronomia. The agronomic traits evaluated under field conditions were: days to flowering, days to maturity, plant height at maturity, height of first pod, stand, reaction to target spot, reaction to downy mildew, green stem and grain yield. The chemical traits were the oil and protein content, evaluated in the Laboratories of Agroenergia and Nutrição Animal, Univerdade Federal de Viçosa. And the traits of seed sanity were the percentage of seed germination and pathogen incidence. We realized individual analysis of variance and compared the means by Tukey test at 5% probability. Verified genetic homogeneity of residual variances, then the joint analysis of variance was done. To evaluate the genotype-byenvironment interaction magnitude and effect, we did the interaction partition in simple and complex parts. Analysis of adaptability and stability of genotypes were performed using the methods of Lin and Binns (1988) modified by Carneiro (1998), centroid modified by Nascimento et al. (2009) and optimum dimensioning of network environments (DORA) proposed in this work. In the study of genetic diversity were used the clustering methods of unweighted pair group using arithmetic averages (UPGMA) and Tocher, using as dissimilarity measure the Mahalanobis distance. All the traits showed significant genotypic, environmental and genotype-by-environment interaction effects. The grain yield, plant height at maturity, height of first pod, seed pathogen incidence and normal seed percentage showed complex type interactions. However, the traits days to flowering, days to maturity, lodging and oil content showed simple type interactions. There was no predominant type of interaction for green stem, reaction to target spot and downy mildew. Using the modified centroid method the genotype BCR1455 178 was classified as maximum adaptability for grain yield and target spot reaction. For downy mildew reaction, BCR553 G306 genotype was classified as maximum adaptability by both Lin and Binns and centroid methods. For oil content BCR1070G 229, CD 219RR, BCR945G 132 and BCR945G 110 showed the highest means and maximum general adaptability. For the seed sanity traits, BCR1070G 251 and BCR1346 142 were classified as being of adaptability to specific favorable environments and BCR553G 306 and BCR1067G 189 adapted to harsh environments. The optimum dimensioning of network environments method (DORA) proposed in this work was adequate to assess the representativeness of trials and useful to optimize decisions regarding the disposal of environments without compromising the recommendation of genotypes. The genetic diversity analysis showed significant variability among genotypes to all agronomic traits. The genotypes DM 309, MSOY 8008, BCR1455 178 and BCR651G 68 were the most dissimilar. The genotypes BCR1057G 162, BCR1067G 210 and BCR553G 306 remained in the same groups in all trials. For the seed sanity traits, the genetic diversity was not seen consistently in the trials.