Seventy diverse genotypes of cluster bean Cyamo-psis tetragonoloba (L.) Taub., representing the broad spectrum of variation from various agro-climatic conditions of India, were assessed for genetic divergence using Mahalanobis D2 technique 1. Thegenetic material exhibited wide range of genetic diversity for all the eleven characters investigated. All the genotypes were grouped in six different clusters. Cluster II consisted of maximum genotypes (30) followed by cluster I (23), III (8), ClustersIV (4), cluster V (3) and VI (2). In general, genotypes developed from same the place were grouped into different clusters indicating that genetic diversity was not parallel to geographic diversity. The clusters V and VI were distinct from the having them two three genotypes indicating their uniqueness for breeding purpose. The highest inter-cluster distances were observed between cluster II and VI (77.27) followed by cluster IV and VI (74.65), cluster III and IV (61.62), cluster V and VI (50.55). Onthe basis of inter-cluster distances and per se performances observed in the present study, a hybridization programme involving genotypes for a specific character be chosen on the basis of cluster mean, say for example if breeder is interested in high number of pods/cluster, he can choose from cluster VI. Similarly for high pod length, one can choose from Cluster III. Cluster II had genotypes which exhibited high mean value for several characters as RGC - 2010 (days to maturity), HGS -833 (days to flowering), IC - 311444 (cluster/plant, pod/cluster and test weight), GAUG -01 -2 -3 (branches/plant), AVKG - 73 (days to maturity) and RGC - 1038 (pod length). Alternatively, selecting one high performing genotype from each of the six groups with respect todays to maturity, branches/plant, days to 50 flowering and seed yield /plant and crossing them in a diallel fashion may also prove to be highly fruitful (2). Thus, on the basis of above-mentioned criteria five clusters pairs were identified for hybridization programme. Out of the five cluster pair, Cluster VI was involved in three cluster pairs. From this cluster pair genotypes with better performance of major seed yield components the seed yield per plant were identified. Thus hybridization programmehas been suggested between nine genotypes i.e, GAUG-0205, RGC-1017, CAZG-04-11, IC-821834, RGC - 2010, AVKG - 73, GAUG-01-2-3, RGC - 1038 and IC-421852 (Table 1 2) to develop populations for direct exploitation. These populat-ions can also be utilizedto produce better inbred to further develop superior hybrids. Therefore, the present investigation suggested hybridization programme between the genotypes of distant groups to obtain superior genotypes from the segregating generations to over come the yield constraints in Kharif cluster bean.
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