Genetic divergence studies in Pigeonpea [Cajanus cajan L. Millsp.]

Abstract

From the results of Mahalanobis's D2 statistics it is revealed that the twenty-seven genotypes were grouped into six clusters. In the present investigation, D² values between all possible pairs of twenty-seven genotypes ranged from 50.41 (cluster IV) and (cluster VI) to 825.41 (cluster III) and (cluster VI). Cluster II had maximum genotypes (10 genotypes) followed by, cluster I (8 genotypes), and cluster III (6 genotypes) and remaining all other clusters viz., IV, V and VI were solitary cluster since they had only single genotype. The distribution pattern of genotypes into different clusters revealed no parallelism between genetic and geographic diversity. The maximum inter cluster distance was found between cluster III and VI (D2 = 825.41), followed by cluster V and III (D2 = 760.65) and cluster III and IV (D2 =578.9) which indicated that hybridization between parents selected from these clusters may create in maximum variability. Cluster-IV rendered highest cluster mean values for the characters viz., number of branches per plant (29.40), number of pods per plant (232.33), Plant spread (29.40) and 100 seed wt. (g) (11.79). Among all the traits, the contribution of contribution of various characters towards the expression of genetic divergence were days to 50% flowering (71.51 per cent), days to maturity (9.40 per cent), plant spread (7.69 per cent), number of branches per plant (3.99 per cent) and 100 seed weight (2.85 per cent) together contributed for about 95.44 per cent of the total divergence. Therefore, these traits should be emphasized during the selection.