Genetic divergence in maize (Zea mays L.)

The genetic divergence among 50 genotypes of maize were estimated by using Mahalanobis D2 statistic for eleven characters. The genotypes were grouped into eight clusters. Cluster III was the largest with 20 genotypes followed by cluster I (12 genotypes), cluster II (8 genotypes), cluster IV (4 genotypes), cluster VIII (3 genotypes) and cluster V, VI, and VII containing one genotype of each. The inter-cluster distances were larger than the intra-cluster distances suggesting wider genetic diversity among the genotypes of different groups. The highest inter-cluster distance was observed between cluster II and cluster VI followed by cluster II and V, cluster II and VII, cluster I and VI, cluster I and VII and cluster IV and VI suggesting more variability in genetic make up of the genotypes included in these clusters. The highest intra cluster distance was noticed in cluster VIII and lowest in cluster V, VI and VII. The clusters, V, VI and VII contained only one genotype and hence, its intra-cluster distance was zero. The cluster VII had highest mean value for grain yield per plant followed by cluster VI, and cluster V. Based on the inter-cluster distances genotypes present in cluster I, II, IV, V, VI and VII can be used as parents for hybridization programme to develop potential hybrids.