Character Association and Causal Effect Analysis for Yield and Yield Components among Early Maturing Genotypes of Soybean (Glycine max L. Merrill)

Abstract

Fourteen early maturing soybean genotypes were evaluated at the experimental area of Barani Agricultural Research Station, Fatehjang, Attock, Pakistan, in 2011 using a randomized complete block design with 3 replications. The objectives of the study were to investigate the correlations among some characters of soybean and to verify direct and indirect effects which will be used for the selection of seed yield. The data regarding eight characters including branches per plant, nodes per plant, pods per plant, seeds per plant, 100 seeds weight, days to flowering, days from flowering to maturity and seed yield were evaluated for phenotypic- genotypic correlations and path coefficient analysis. Means for yield and its components were significantly different among all genotypes for all characters. Significantly positive phenotypic correlation was observed between seed yield and days to flowering. Furthermore, genotypic correlation showed that seed yield was positively correlated with all characters except 100 seeds weight. Pods per plant showed the highest positive direct effect on seed yield, followed by branches per plant. In addition, the indirect effects of most characters were high through pods per plant. The results obtained from genotypic correlations and path analyses showed that the efficiency of selection for seed yield in early maturing soybean should increase through the selection of pods per plant.