GENETIC ANALYSIS OF DUAL PURPOSE TRAITS IN SOYBEAN

Soybean genotypes TGX1448-2E and TGX1987-62F were evaluated in complete randomised block design with three replications Data were collected on plant height, days to first flower, number of primary branches, pod weight, leaf weight, stem weight, seed weight, fodder yield, total biomass, days to 50% flower and 50% maturity. The dual purpose variety TGX1448-2E had comparatively significant performance than TGX1987-62F in terms of number of primary branches, pod weight, leaf weight, stem weight, seed weight, fodder yield and total biomass. Result of ABCD scaling test revealed the inadequacy of the additive –dominance model in elucidating the mode of gene action for some of the traits being studied. Epistatic effects were found significant for plant height, days to first flower, number of primary branches, seed weight, fodder yield, total biomass, days to 50% flower, and days to 50% maturity. Cross TGX1448-2E x TGX1987-62F indicated duplicate gene action for number of primary branches, pod weight, stem weight and days to first flower. Cross TGX1987-62F x TGX1448-2E also showed duplicate gene action for plant height, number of primary branches, pod weight, days to 50% maturity, fodder yield and seed yield. Heritability in broad sense was found to be high for plant height, days to first flower, number of primary branches, pod weight, leaf weight, total biomass, days to 50% flower and 50% maturity. The results of genetic analysis of dual purpose trait for soybean has revealed complex genetic behaviour particularly additive and dominance components. This complex behaviour could be exploited for the improvement of any desirable traits in soybean through delaying selection until attainment of homozygosity