Appraisal of genetic variability in sodium azide induced rice mutants to identify selection criteria for higher yield using quantitative attributes

Abstract

Induced mutation is an effective tool in generating variability of crop plants. Identification of efficient genotypes with improved yield requires knowledge of genetic variation in yield and yield contributing traits. Therefore, an investigation was conducted to develop variants through azide mutagenesis and estimation of genetic variability of the mutants to detect selection standards towards higher yield. Mature rice seeds were mutagenized with estimated LD50 concentration. A hundred mutants were grown-up accordingly and their quantitative traits were evaluated through multivariate analysis to assess genetic variability. Every assessed trait except grain length exhibited highly significant variation for all mutants. The high genotypic and phenotypic coefficient of variation along with high heritability and genetic advance as a % of mean was accounted for total and filled grains panicle-1. Grain yield was positively and significantly correlated with total grains panicle-1, filled grains panicle-1 and straw yield hill-1. Besides, higher variance was also associated with these traits. Ward’s Agglomerative clustering grouped the mutants into 7 major clusters. More than 36% of total variation was associated with first 2 principal components (PCs) and was mostly with total grains panicle-1 and filled grains panicle-1 whereas third and fourth PCs were mainly accounted for straw yield hill-1. Thus, these traits should receive special attention during selection of yield potential genotypes. Presence of genetic variation in mutants was ensured for most of the traits and selection based on greater tillers hill-1, grains panicle-1 and straw yield hill-1 may open a new avenue towards improved yield and other traits in rice.