Genetic variability, correlation and path analysis for yield and yield contributing characters in soybean (Glycine max L.)

The genetic variability studies carried out on 50 soybean genotypes indicated that the estimate of phenotypic coefficient of variation were greater than those of the genotypic coefficient of variation for all the traits studied. The close proximity between PCV & GCV values for most of the characters indicated less influence of environment on the expression of the characters under study. Considering heritability, most of the characters showed high values. High heritability coupled with high genetic advance as per cent of mean were recorded for biological yield plant−1, harvest index, number of seeds plant−1, seed yield plant−1 and number of pods plant−1 indicating the scope of improvement through direct selection. Correlation analysis revealed that number of pods node−1, number of seeds plant−1, biological yield plant−1, number of nodes plant−1 and harvest index were positively and significantly associated with seed yield plant−1. Path analysis revealed that number of pods node−1 had the high positive direct effect on seed yield plant−1 followed by number of nodes plant−1, number of seed yield plant−1, biological yield plant−1 and harvest index. Traits viz., number of pods plant−1, days to 50% flowering, days to maturity had negative direct effect on seed yield plant−1. Most of the other traits had indirect effect via number of branches plant−1, number of pods plant−1 and 100-seed weight. Hence, these characters should be given more weightage in selection programme of high yielding soybean genotypes.