Estimativa de parâmetros genéticos e fenotípicos da qualidade de sementes de soja

Abstract

Currently the demand is not only for productive soybean cultivars, but also for seeds with high physiological quality. Since the cultivation of this oilseed in the south of Minas Gerais has increased and there are not any companies of genetic improvement with specific cultivars for the region, we evaluated seeds of progenies coming from the breeding program of recurrent selection of the Federal University of Lavras, aiming to estimate the genetics and phenotypics parameters regarding seeds quality. In the season 2015/2016, 142 seeds of progenies produced in Lavras-MG were evaluated. At the season 2016/2017, 64 seeds of progenies produced in Lavras-MG, ItutingaMG and Nazareno-MG were evaluated. The tests in laboratory were performed using completely randomized design with four replications. Seeds quality were evaluated for germination test, seedlings length, seedling emergence and the tetrazolium test. The attributes evaluated were: germination, length of radicle, length of hypocotyl, vigor, viability of seeds, mechanical damage, bedbugs damage, humidity damage, emergence speed index and seedling emergence. Heritability, selection gains and the components of variance were estimated by mixed models using the R software. The accuracy estimates reflected medium a nd high magnitude. The components of variance due to the source of variation were significant for most of the characters, evidencing the existence of variability. The genotypes versus environments (GxE) interaction was significant. Therefore, environmental factors have affected the production of seeds. The magnitude of heritability and selection gains refers to the possibility of success for improvement for seed physiological quality. Correlated response estimates allow to infer that selection for grain yie ld reflects on gains in seeds physiological quality.