Morphometric Diversity Studies in Rice Genotypes for Yield and Yield Attributing Characters under Drought

Abstract

Selection of parents for hybridization has widely been associated with degree of divergence among the selects. Mahalanobis D² analysis was carried out involving a set of 76 rice genotypes, landraces and popular variety consisting of both indigenous and exotic collection were studied for yield and yield related attributing traits under drought. Based on D² analysis, the genotypes were grouped into 8 clusters. Maximum number of genotypes (48 genotypes) was grouped in cluster I. The maximum inter cluster distance was observed between cluster II and VI (840.14) followed by between cluster VI and VIII (815.34) possessing wider genetic diversity among the genotypes between these groups. The hybrids developed from the selected members of these clusters would produce highly variable population in the segregating generations. The maximum intra cluster distance was observed in cluster III (71.67) followed by cluster II (54.07). Hence, selection within these clusters may be exercised based on the highest areas for the desirable traits, which would be made use of in improvement through intervarietal hybridization. Among the 11 traits studied, plot yield contributed maximum divergence (56.49%) followed by 1000 grain weight (22.28%). The traits viz., harvest index, sterility, plot yield, kernel length, kernel breadth, 1000 grain weight contributed 88.78% towards total divergence. Therefore, these characters may be used for initiating a hybridization programme to develop drought tolerant genotype.