Genetic variability and trait relationships among yield and other quantitative traits in soybean [Glycine max (L.) Merrill]

The study was taken up during 2006–2007 to generate information on the variability and character relationships in different quantitative traits of 25 genotypes of soybean grown under complete randomized block design. The genotypes evaluated showed that both phenotypic coefficient of variation and genotypic coefficient of variation were higher for most of the traits and was a close relationship between PCV and GCV. High genetic coefficient of variation accompanied with high heritability and genetic gain were recorded for days to flowering and maturity, plant height, number of pods/plant and 100-seed weight indicating the additive type of gene action which could be improved by simple selection. The genetic correlation was higher than corresponding phenotypic ones for most of the traits implying inherent relationship among them. Oil content expressed highest positive and significant phenotypic and genotypic association with days to flowering and maturity, plant height, primary branches/plant and seed yield and positive correlation with primary branches and seeds/pod. Path analysis showed that plant height, pods/plant, seeds/pod and 100-seed weight had positive direct effect through each other on seed yield.