Caracterização de populações de aveia preta e estratégias de seleção de genótipos superiores

Abstract

The aim of study was to characterize black oat populations through statistical and biometric models, in order to obtain information for selection of superior genotypes. Research was conducted in experimental area of Genetic Breeding and Plant Production Laboratory, Federal University of Santa Maria, Campus of Frederico Westphalen-RS. For this purpose, 14 black oat populations were used, which were collected in cities of Rio Grande do Sul. Initial evaluations were proceeded with populations collected: length and width seed (mm), weight of thousand seeds (g), first germination count (%), germination (%), aerial part and root length of seedlings (mm), dry matter of seedlings (g). Subsequently, a field experiment was carried out in a randomized block design, with 14 populations arranged in three replications, in agricultural year 2014. At physiological maturity stage, were measured: plant height (cm), number of tillers, panicle length (cm), number of grains per panicle, number of branches of panicle, ratio between panicle weight and panicle grain weight, weight of thousand grains, grain yield (kg ha-1). Families of black oat breeding program were used to others studies, being 76 families of black oat and three controls (BRS Madrugada, BRS Centauro, BRS 139 Neblina), which were conducted in two agricultural crops (2016 and 2017), using families with intercalary controls experimental design. And following characters were evaluated: days of emergence to flowering, plant height (cm), panicle length (cm), number of fertile tiller, panicle weight (g), panicle grain weight (g) and ratio between panicle weight and panicle grain weight. Based on the information obtained, populations were characterized by Pearson correlation analysis, path analysis, variance components and genetic parameters, genetic diversity, as well as phenotypic, genetic and environmental correlations. Weight of thousand seeds, percentage of germination, grain width, panicle grain weight contribute significantly to differentiation of black oat populations, revealing that there is genetic variability. In addition, for greater selection gains of superior genotypes, it should be prioritized panicle length, number of grains per panicle, panicle weight and panicle grain weight. Associations between grain width and physiological quality, number of grains per panicle with grain yield, and still high heritability revealed by panicle weight and panicle grain weight, should be highlighted for selection efficiency. Despite divergent conditions between agricultural years studied, genetic origin of variance components prevails. The observed variance between populations and controls shows that the selection of superior genotypes to compose breeding program, is promising.