Genetic variability and path analysis in exotic hybrid rice genotypes

Abstract

ABSTRACT : Variability, correlation and path coefficients for seven morphological characters were studied on 17 exotic rice hybrids with three check varieties which were imported from different countries. Genotypic and phenotypic coefficients of variation were high for grain yield and number of spikelets per panicle; moderate for 1000 grain weight and low for growth duration, panicle length and panicles per m2. High heritability accompanied by high to moderate genetic advance for number of spikelets per panicle, 1000 grain weight and grain yield indicated the predominance of additive gene action for the expression of these characters. Grain yield was found to be positively and significantly correlated with plant height, number of panicles per m2, number of spikelets per panicle, 1000 grain weight and growth duration at both genotypic and phenotypic levels indicating the importance of these characters for yield improvement in this population. The results of genotypic path analysis revealed that spikelet number per panicle had the highest positive direct effect followed by 1000 grain weight and growth duration. The overall results indicated that selection favoring larger number of spikelets per panicle and 1000 grain weight with a reasonable balance for moderate growth duration would help to achieve higher grain yield in this population of rice hybrids.