Analysis of genetic diversity of 120 genotypes of Glycine max (L.) merrill by using D2 analysis

Abstract

Soybean is an essential legume crop all over the world where it serves to meet the increasing demands for protein, edible oil and calories. In this study, we analysed genetic diversity of 120 soybean germplasm lines by using D2 analysis. An experiment was conducted in randomized augmented block design at ICAR-Indian Agricultural Research Institute (IARI), during kharif-2016-17.The analysis of variance showed significant differences for seven morphological traits viz., days to 50% flowering, days to maturity, plant height (cm), primary branches per plant, pods/plant, 100- seed weight (g) and seed yield / row (g). Narrow differences between phenotypic and genotypic coefficients of variation (PCV and GCV) for all the characters coupled with high heritability were found for characters such as primary branches / plants, Pods/plant and seed yield /row revealed that additive gene action is predominant. The genetic advance in percentage of the mean was higher for all the characters under study except primary branches/plant and 100 seed weight (g).The genetic divergence assessed using D2 statistics for characters enabled grouping of all the genotypes in eleven distinct clusters. Maximum (17) genotypes were grouped in cluster X and minimum (3) in clusters VI. The inter cluster distance in matrix ranged between 2.98 to 10.45.The maximum intra-cluster distance was recorded in cluster V, followed by cluster II while, minimum intra-cluster distance was recorded for cluster IX followed by cluster X. The maximum inter-cluster distance was found in the cluster VII (60.78) followed by the cluster IX (47.97), cluster VI (47.05), cluster VIII (43.98), cluster V (41.42 and 39.24) followed by the cluster X (39.70) respectively. The minimum inter - cluster distance was being observed between cluster IX (8.91) and cluster X (7.02) .The highest cluster mean for seed yield / row in (g) was recorded in case of cluster V followed by cluster XI whereas minimum cluster mean was recorded in cluster III.