GENETIC DIVERSITY ANALYSIS IN SOYBEAN (Glycine max (L.) Merrill)

Abstract

A field experiment was conducted during November 2011 to March 2012 to study the genetic diversity for quantitative traits in soybean (Glycinc may L. Merrill) with 25 genotypes in randomized block design with three replications. The genotypes were placed in a field experiment conducted at the research farm of Sher-e-l3angla Agricultural University, Dhaka- 1207. The objectives of the study were to asses the genetic diversity among the genotypes of soybean, to find out the characters influencing genetic divergence, to estimate heritability and genetic advance of yield and yield components, to screen out the parental groups which are likely to provide superior segregants on hybridization and to know the yield potentiality of genotypes. Analysis of variance for each trait showed significant differences among the genotypes. Phenotypic coefficients of variation (PCV) was also close to genotypic coefficients of variation (GCV) for all the characters except branches per plant, pod length and seeds per pod, effective node number indicating that environment had influence on the expression of these characters. High heritability associated with high genetic advance percent of mean was observed for pod length and hundred seed weight which indicated that selection for these characters would be effective. Hence, thrust has to be given for these characters in future breeding programme to improve the yield in soybean. Multivariate analysis based on 13 agronomic characters indicated that the 25 genotypes were grouped into five distant clusters. The maximum contribution of characters towards diversity was observed by days to maturity, seeds per pod and seed yield per plant. Thus, these traits may be given high emphasis while selecting the lines for hybridization. The inter cluster distance was maximum between cluster I and cluster IV. The highest intra-cluster distance was found in cluster IT. From the results it can be concluded that the following genotypes vi:., G1r. (BD-2339), G12 (RD-2335), G13 (BD-2336), and GJ4 (BD-2337) were identified as potential genotypes for higher seed yield in soybean.