Nature and magnitude of genetic diversity among locally adapted rice (Oryza sativa L.) genotypes

Abstract

Present study was carried out during kharif 2015 at Experimental Area of Division of Plant Breeding and Genetics to assess nature and magnitude of genetic diversity among 32 locally adapted rice genotypes using Mahalanobis D2 statistics. Analysis of variance indicated presence of notable genetic variability for yield, its components and quality traits. Estimates of components of variance indicated that genotypic variance contributed maximum to the phenotypic variance, suggesting that available genetic variability can be exploited through selection and hybridization. Based on D2 analysis 32 rice genotypes were grouped into six clusters. Among these clusters cluster VI consists of 8 genotypes (SJR 51, Jaya, Giza 14, RR 8585, Shalimar rice 2, Shalimar rice 3, SJR 41 and SJR 45) forming the largest cluster followed by cluster II with seven genotypes (Pusa Basmati 1, Pusa sugandh 2, IARI 1460, RR 600, CSR 30, Pusa Basmati 1121 and Jammu Basmati 129), cluster I with six genotypes (Basmati 370, SJR 80, Basmati 564, SJR 81, Saanwal Basmati and Ranbir Basmati) cluster IIIrd and Vth with four genotypes each (Basmati 1509, SJR 5, Pusa Sugandh 5, Taroari Basmati and K-332, K-39, K-343, K-448) and cluster IV with three genotypes (Ratna, IET 1410 and PC 19). Inter cluster distances were found to be higher than intra cluster distances indicating wide genetic diversity among the genotypes. Contribution of various characters towards expression of total genetic divergence indicated that 1000 grain weight contributed a maximum (38.25%), followed by plant height (20.16%) and grain yield per plot (14.92%). The variation present among rice genotypes under study can be exploited through selection and hybridization among identified genotypes.