Exploring morphological diversity for seed yield and component traits in Indian mustard under timely and late sown conditions of Bihar

Abstract

Genetic divergence among 44 genotypes of Indian mustard was estimated using Mahalanobis' D2 statistics and total of 14 clusters were formed in timely sown condition and 7 clusters in late sown condition. Cluster I had maximum number of genotypes (27) in timely sown condition followed by cluster IV with 4 genotypes and cluster XIV with 2 genotypes all the other clusters viz. Cluster II, III, V, VI, VII, VIII, IX, X, XI, XII and XIII had one genotype each in them. In late sown condition out of 7 clusters formed Cluster I had maximum (34) number of genotypes followed by cluster II and cluster IV with 4 & 2 genotypes respectively while cluster III, V, VI and VII had one genotype each. Inter Cluster distance was observed highest between cluster IX and Cluster XIV (458.52) followed by cluster VIII and cluster XIV (367.37) and cluster II cluster XIV having a distance of 334.49 in timely sown condition. Larger distances between the clusters suggest more genetic diversity between the genotypes present in them which mean genotypes present in these clusters can be used as parents in breeding programmes. In late sown condition Cluster VI and Cluster VII showed highest maximum distance of 1138.26 followed by clusters II and VII exhibiting a distance of 1125.53 and cluster IV and Cluster VII at a distance of 679.73 in late sown condition. Intra cluster distance showed a maximum distance in cluster I (149.87) followed by cluster II (149.34). Four clusters Cluster III, V, VI and VII showed a intra cluster distance of zero in late sown condition. Cluster I and cluster II can be used in breeding programmes owing to their large intra cluster distance. In timely sown condition Cluster XIV (100.18) followed by cluster IV & cluster I showed a distance of 92.19 & 81.36 respectively. All the other clusters showed an intra cluster distance of zero, showing no intra cluster diversity. Therefore, it was concluded that more emphasis should be given on cluster VI for selecting genotypes as parents for crossing with the genotypes of cluster I which may produce new recombinants with desired traits.