​Genetic Diversity for Seed Yield and its Components in Clusterbean [Cymopsis tetragonaloba (L.) Taub

Abstract

Background: Clusterbean [Cyamopsis tetragonoloba (L.) Taub.] (2n=2x=14) is an under exploited legume belonging to family fabaceae. Clusterbean is a versatile legume crop cultivated mostly as animal feed, green manure green leaves as fodder, vegetable and cover crop. Clusterbean is a drought resistant, hardy, deep rooted annual legume crop. D2 statistics provides a measure of magnitude for divergence between two genotypes under comparison. For broadening the genetic base of cultivars, the genetic diversity present in cultivated and wild relatives must be explored. Generally, diverse germplasms are expected to give high hybrid vigor and hence, it necessitates studying genetic divergence among the existing varieties and genotypes for the identification of parents for hybridization programme. Methods: The present investigation was undertaken to study genetic variability in clusterbean [Cymopsis tetragonaloba (L.) Taub] with using a set of 40 genotypes at Agronomy Instructional Farm, Department of Agronomy, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar during Kharif 2019 in randomized block design with four replications. Mahalanobis (1928) D2 statistic was used for assessing the genetic divergence between different populations. Grouping of the genotypes in different clusters was done by using Tocher’s method. The inter-cluster distance was calculated by measuring the distance between clusters I and cluster II, between clusters I and cluster III, between clusters II and cluster III and so on. Likewise, one by one cluster was taken and their distances from other clusters were calculated. Result: The genetic diversity analysis revealed the formation of nine clusters suggested the presence of considerable genetic diversity among the 40 genotypes. The clustering pattern indicated that geographic diversity was not associated with genetic diversity. The analysis of per cent contribution of various characters towards the expression of total genetic divergence indicated that, the number of branches per plant followed by gum content, days to maturity, days to flowering contributed maximum towards total genetic divergence. On the basis of inter cluster distances, cluster IX was found to be more divergent. Therefore, it was concluded that the genotypes belonging to these cluster should be inter crossed in order to generate more variability.