Abstract

                                The present investigation was conducted with forty-six Indian mustard genotypes involving B. juncea x B. juncea and related species i.e. B. juncea x B. carinata, B. juncea x B. napus and somaclone background. These were evaluated to identify the genetically diverse genotypes for exploitation in a breeding programme aimed at improving yield potential of Indian mustard. Amongst seven clusters formed (Mahalanobis D2, 1936), each of the cluster I and IV had the largest genotypes (nine) and cluster II with smallest (two genotypes). Maximum divergence was observed between cluster V and VI followed by cluster V and VII and cluster II and VI. The genotypes RAURD-166, RAURD-205, RAURD-241, RAURD-32, JD-6, RAURD-168, RAURD-78, RAURD-195, RAURD-246, RAURD-172, RAURD-25 and RAURD-34 were observed as more divergent. Cluster V recorded minimum for plant height with early flowering and maturity, cluster VI, had more for primary branches per plant, secondary branches per plant, number of siliqua per plant, number of seeds per siliqua, biological yield per plant and seed yield per plant. The cluster VII had high mean for length of main raceme, siliqua on main raceme and seed yield per plant and cluster II, had high mean value for siliqua density. The clusters VI, VII, V and II were observed as more divergent clusters with high seed yield. The probability of getting better segregants and promising recombinants is expected to be more, from selecting genotypes of these clusters.

Key words : Brassica juncea L., genetic divergence, D2 analysis, cluster analysis.