Desempenho agronômico de genótipos de soja e cruzamentos potenciais para ciclo e produtividade.

Abstract

Culture deserves great prominence as it is one of the main commodities produced in the world and for this reason it is part of agricultural activities with greater prominence in the world scenario. The soybean breeding programs combined with production technology are the main responsible for the success of crop agribusiness in the country, aiming at the development of more productive soybean genotypes, resistant to the main pest insects and crop diseases and adapted to different regions. of cultivation. In view of this, the present study aimed to evaluate agronomic performance, genetic diversity and to indicate promising crosses of soybean lines and cultivars, aiming at precocity and grain yield. The experiment was carried out at Fazenda Capim Branco, belonging to the Federal University of Uberlândia. Twenty-two genotypes and three soybean cultivars were evaluated, UFUS 6901, UFUS 7415 and TMG 801 (commercial cultivar), in a randomized block design with three replications and 12 agronomic characters were evaluated: number of days to maturity (NDM), plant height at flowering (APF), plant height at maturity (APM), number of nodes on main stem at flowering (NNF), number of nodes on main stem at maturity (NNM), number of productive nodes (NNP), number of pods with 1 grain (NV1), number of pods with 2 grains (NV2), number of pods with 3 grains (NV3), total number of pods (NTV), number of pods without grains (NSV) and grain yield in kg ha-1 (PROD). The genotypes showed a total cycle ranging from 120 to 145 days. The existence of genetic variability at the level of 5% was detected by the F test for the characters, except for the number of nodes in flowering. The values of the coefficient of genotypic variation varied from 38.81% to 75.15% for the characters NNF (number of nodes in the main stem at flowering) and NDM (number of days to maturity), respectively, and the most productive genotypes were: UFUS 04, UFUS 11, UFUS 12, UFUS 6901, UFUS 7415 and UFUS B8. The genotypes were grouped by the UPGMA and Tocher methods, which obtained different results. By the UPGMA method, five groups were formed and by the Tocher method, three groups were formed. The characters number of pods with 2 grains (UFUS 17) and total number of pods (UFUS 04) were the ones that most contributed to the genetic dissimilarity between the genotypes. The genotypes UFUS 6901, UFUS 7415 and UFUS 12 were the only ones selected for the characters NDM, NV3 and PROD, indicating that they are genotypes with high potential for productivity and precocity.