Análise de parâmetros genéticos avaliados em cruzamentos dialélicos de trigo (Triticum aestivum L,) em dois ambientes.

Abstract

The selection of parents for a breeding program, is the main step to obtain genotypes with superior genetic constitution, however, the selection based only on phenotype is influenced by the environment, undermining the recommendation of cultivars for different environments. Thus, the aim was to estimate the general (GCA) and specific (SCA) combining ability, inbreeding depression and heterosis in F1 and F2 generations in two environments, Pelotas and Pato Branco, by diallel cross of eight wheat genotypes. Eight elite parents were crossed in a diallel, excluding reciprocals. The results revealed a greater participation of additive effects in the expression of genotypic constitutions used. The cultivars that had higher values for GCA were BRSTangará (EP), BRS Guamirim (NAFP), Quartzo (NGE, PE, MMG) and Mirante (PGP), The best hybrids, were in accordance with locations, generation, GCA and SCA averages: 1 (BRS Tangará x F. Cristalino), 2 (BRS Tangará x BRS Guamirim), 3 (BRS Tangará x Quartzo) e14 (BRS Guamirim x Quartzo). The hybrid combination displaying high heterosis were a function of the conmbination of at least one parent with high performance and high GCA, The BRS Guamirim x CD 114, BRS CD Guamirim x 117, 114 x Vaqueno CD, CD 117 x Vaqueano, heterotic effects were considered high when the generation x location interactions were considered. Thus, this study revealed differences in the genetic parameters of GCA, SCA and heterosis of eight genotypes of wheat, evaluated in two environments.