Genetic Divergence and Variability Assessment of Rice (Oryza sativa L.) Genotypes for Yield and its Contributing Traits

Abstract

For over half of the world's population, rice is the primary food. An increasing population requires higher yield levels, which must be achieved. In order to construct breeding strategies and improve production, variability must be created. Fourteen distinct parameters were used to examine genetic variability in forty enhanced rice genotypes. Genotypes exhibited moderate values of GCV and PCV for effective tillers per plant, panicle length, grains per panicle, 1000 grain weight, grain yield per plant, straw yield per plant and length/birth ratio and high values for protein content indicating the greater scope of improving these characters by applying judicious selection. High heritability coupled with high genetic advance as percentage of mean showed by straw yield per plant, grain yield per plant, grains per panicle, 1000 grain weight and effective tillers per plant indicated higher additive gene action in these traits thus improvement by direct phenotypic selection over the genotypes would be worth it. D2 statistics were estimated on forty genotypes which revealed generalized distance (D) from 17.54 to 55.25 between five clusters, indicating the presence of vast diversity. Considerable higher intra and inter cluster values revealed a very interesting trend of genetic diversity. The maximum inter cluster distance was found between clusters II and III followed by clusters III and V. Based on cluster analysis intercrossing among the genotypes in distant clusters would produce highly heterotic progenies. Maximum contribution towards the divergence was exhibited by protein content followed by days to 50 per cent flowering and 1000 grain weight.