Karnwal, M.K.Sahoo, Santanu Kumar2021-01-272021-01-272020-11https://krishikosh.egranth.ac.in/handle/1/5810160649The present investigation was carried out at N. E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India, during kharif, 2019 with 23 genotypes (9 cross and 14 parents and each cross containing 5 lines of high yielding, 5 lines of low yielding and 5 lines of bulk) of soybean for fourteen quantitative characters to assess genetic variability, inter-character correlation and their direct and indirect effects on seed yield and the best selection practices in advance generation of soybean. Highly significant differences among the treatments were found for all traits studied, indicating the presence of sufficient amount of genetic variability among the experimental materials. Estimated values of phenotypic coefficient of variation were higher than genotypic coefficient of variation for majority of the characters under study. Seed yield per plant showed highest phenotypic coefficient of variation (29.21%) as well as genotypic coefficient of variation (29.1%). The highest heritability estimates were reported in group of characters viz. plant height, number of pods per plant, seed yield per plant, harvesting index and seed yield efficiency which directly influence the seed yield. The value of genetic advance ranged from 0.06 (number of seeds per pod) to 89.45 (seed yield per row). The highest genetic advance as percent of mean was reported for seed yield per plant (59.84%). The highest value of heritability along with high estimates of genetic advance as per cent mean exhibited by seed yield per plant (g) followed by dry matter weight per plant (g), seed yield per row, number of pods per plant, seed yield efficiency, number of primary branches per plant and plant height (cm) which showed the presence of additive genetic action. High heritability coupled with low genetic advance as per cent mean was found in days to maturity followed by days to 50% flowering, plant height, number of seeds per pod and number of nodes per plant indicating the influence of non additive effects on the expression of such characters. Seed yield per plant showed significant positive phenotypic and genotypic correlations with number of pods per plant (rp=0.974, rg=0.975), dry matter weigh per plant (rp=0.927, rg=0.927), number of primary branches per plant (rp=0.755, rg=0.767), seed yield efficiency (rp=0.740, rg=0.741), harvesting index (rp=0.723, rg=0.724), number of seeds per pod (rp=0.690, rg=0.0.690), days to maturity (rp=0.395,rg=0.402) and plant height (rp=0.348,rg=0.350). Path coefficient analysis indicated that number of pods per plant and seed yield efficiency exhibited high positive correlation coupled with high positive direct effect in influencing seed yield. Among the high yielding lines, C7(PS 1583×Bragg) showed the highest per se performance whereas C9(RVS2000-1×PS1092) showed the lowest per se performance. Similarly, among low yielding lines the highest and the lowest per se performances shown by C7(PS1583×Bragg) and C9(RVS2000-1×PS1092), respectively. The highest and lowest per se performances among the bulk lines reported in C7(PS 1583×Bragg) and C1(JS20-29×JS20-55) crosses, respectively. In advance generation, bulk method selection was found better performing than the pedigree method for yield and yield contributing traits. Investigations of inter correlation analysis within the same family as well as between families and mean seed yield per plant and row study revealed that bulk method of selection was better performing than pedigree method for all crosses except C1 (JS 20-29× JS 20-55). Among all crosses, cross C7 (PS1583× Bragg) was identified as the best cross to find out transgressive segregants in letter generations for yield improvement in soybean.EnglishThesis