Trait association studies in soybean genotypes under post anthesis drought stress

The present study was carried out during kharif 2018 considering 30 soybean genotypes under both stress and normal condition. Analysis of variance, correlation and path coefficient analysis were studied. The analysis of variance under both stress and normal condition revealed that the mean sum of squares due to genotypes were highly significant for all traits under study. Correlation analysis revealed that seed yield per plant showed highly significant correlation with harvest index followed by number of seeds per plant, number of pods per plant, biological yield per plant, number of seeds per pod and number of pod clusters per plant under stress condition whereas under normal condition, seed yield per plant showed highest significant positive correlation with harvest index followed by biological yield per plant, number of seeds per plant, number of pod clusters per plant, number of pods per plant and 100 seed weight. Path coefficient analysis of different yield traits under stress condition revealed that harvest index, biological yield, number of seeds per plant, days to 50% flowering recorded positive direct effect on seed yield per plant. These traits have also shown positive indirect effect via each other which indicated that simultaneous improvement of these traits and ultimately the yield can be achieved. Whereas, path coefficient analysis of different yield traits under normal condition revealed that harvest index have shown high positive direct effect on seed yield per plant number of pod clusters per plant, days to flower initiation, biological yield per plant, number of seeds per plant, number of secondary branches per plant and 100seed weight showed positive direct effect on seed yield perplant. Days to flower initiation, number of pods clusters per plant, number of seeds per plant, biological yield and harvest index have also shown indirect effect via each other.