Assessment of genetic diversity in inbred lines of maize (Zea mays L.) and its relationship with heterosis

Abstract

The genetic divergence among thirteen genotypes of maize were estimated by using Mahalanobis D2 statistic for ten characters. The genotypes were grouped into three clusters. Cluster I comprised 11 parental genotypes (CLQR, VL111, R4093, R6429, S8481, S8200, CML490, HK1, WLS, CLQRC and G18), while Cluster II (CLQ25) and III (CG18) were mono-genotypic. The highest inter cluster distance was recorded between cluster II and III (4.88) followed by cluster I and III (4.67). Maximum genetic distance was observed between the parents WLS and G18, whereas minimum distance was observed between the parents VL111 and S8481 suggesting more variability in genetic makeup of the genotypes included in these clusters. Cluster I comprising of 11 genotypes have maximum mean values for number of kernels per row and number of kernels row per cob while minimum mean values for plant height and ear height. Cluster II containing only CLQ25 have maximum mean values for ear girth and grain yield per plant. The highest contribution in the manifestation of total genetic divergence was exhibited by grain yield per plant (28.63%) followed by ear girth (28.47%), ear length (19.23%), number of kernel per row (11.50), number of kernels row per cob (10.04). Out of 30 crosses, 11 crosses showed positive significant heterobeltiosis for grain yield per plant. The crosses CLQ25 × CLQR and WLS × R4093 belongs to high divergent class. It could be concluded that genetic diversity can be utilized as a reliable parameter for predicting heterosis in hybrids.