Estimation of genetic variability, correlation and path coefficient analysis for evaluation of submergence tolerant rice genotypes

ABSTRACT: Submergence is a serious environmental condition that causes large loss in rice production in rain fed lowland and flood affected area. Rice (Oryza sativa L.) is considered as a submergence-sensitive crop species. Within this species, there are considerable varietal differences in sensitivity to this environmental stress. The experiment was conducted in the exprimental farm of Bangladesh Rice Reserch Insitutute, Gazipur, Bangladesh during 2014-2015 to evaluate 46 submergence tolerant rice genotypes through genetic variability, correlation and path analysis. Most of the charactersof genotypic coefficients of variation (GCV) and phenotypic coefficients of variation (PCV) values were close to each other, which indicated that those characters were controlled by genetic factors. High heritability coupled with high genetic advance as percent of mean was fastened for panicle weight, spikelet fertility percentage, thousand grain weight and grain yield suggesting preponderance of additive gene action in the expression of these characters. Correlation study revealed that significant correlations at both phenotypic and genotypic level exist between yield per plant and panicle weight, spikelete fertility percentage, and thousand grain weight. Path coefficient analysis revealed that panicle weight, spikelet fertility percentage, days to maturity and thousand grain weight had direct positive effect on yield, indicating these are the main contributors to yield. This study reveal that panicle weight, spikelet fertility percentage, days to maturity and thousand grain weight may serve selection criteria for improving genetic potential of rice. 

Keywords: Genetic variability, heritability, correlation, path analysis