Genetic analysis of F6 and F6:7 soybean generations

Abstract

For estimating genetic parameters and selecting superior lines for grain yield, forty-five soybean (Glycine max L.) crosses in F6 and F6:7 generations were evaluated. The soybean lines FT-Cristalina, EMGOPA-301, IAC-4, IAC-5, IAC-6, IAC-8, IAC-9, IAC-11, Santa Rosa, and OCEPAR-9-SS-1 were used in the crosses. The F6 progenies of 44 crosses (except EMGOPA-301 x IAC-5) and the ten parents were evaluated as well as the F6:7 progenies from all 45 crosses and the ten parents in the next crop. The number of days to maturity (NDM), plant height at maturity (PHM), agronomic value (AV) and grain yield (GY) were evaluated for both generations. There was some difficulty to select early top yield lines due to the high positive genotypic correlation between GY and NDM. The heritability estimates were high (> 0.70) and moderate (0.40 – 0.70) for NDM and PHM, respectively. The presence of transgressive segregates indicated the possibility of selecting lines with high grain yield.