Estimation of Genetic Variability, Direct and Indirect Effects of Yield Contributing Characters on Grain Yield of Upland Rice (Oryza sativa L.) Germplasm

Abstract

A study was carried out using 24 upland rice genotypes grown in randomized block design with three replications to estimate genetic variability, correlation and path coefficient analysis. Based on the mean performance, of high grain yield per hill, the genotype SHUATS UPR-13 followed by SHUATS UPR-11 were identified to be superior. High phenotypic and genotypic coefficient of variation were observed for grain yield per hill, biological yield per hill and number of panicles per hill. High heritability coupled with high genetic advance as percent of mean was observed for grain yield per hill, biological yield per hill, number of panicles per hill, number of tillers per hill indicating that genotypic variation present in the genetic material studied is probably due to additive genetic variance, which can be effectively exploited in crop improvement programme. The traits biological yield per hill, number of tillers per hill, number of panicles per hill, plant height, harvest index were found to have positive significant association with grain yield per hill at both genotypic and phenotypic level. Hence, selection of these traits shall help in selecting the genotypes with high grain yield per hill. Number of tillers per hill, panicle length, biological yield per hill, harvest index had positively direct effect on grain yield per hill at both genotypic and phenotypic level. Therefore, effective selection must be attempted for these traits which would help in the improvement of grain yield in rice genotypes suitable for different environments.