Phenotypic and Genotypic Correlation and Path Coefficients in Rainfed Upland Rice (Oryza sativa L.) Genotypes at Guraferda, Southwest Ethiopia

Abstract

A field experiment was conducted with the objective of determining the magnitude of association between yield and yield component characters. Fifteen rainfed upland rice genotypes were evaluated in randomized complete block design in three replications for two consecutive years (2014 and 2015) in southwest Ethiopia. Correlation coefficient analysis of grain yield showed positive and significant association with days to 85% maturity and number of fertile tillers per plant at both phenotypic and genotypic levels. At phenotypic level, thousand seed weight displayed positive and significant correlation with grain yield, while at genotypic level, panicle length and plant height exhibited positive and significant relationships. Thus, these traits could play pivotal role in the development of high yielding rainfed upland rice genotypes. Separation of correlation coefficients into direct and indirect effects of component traits on grain yield revealed that days to 85% maturity and number of fertile tillers per plant exerted the maximum positive direct effect on grain yield at both genotypic and phenotypic levels. The direct contribution of days to 85% maturity supported indirectly by panicle length and thousand seed weight at phenotypic level. At genotypic level, panicle length assisted the direct contribution of days to 85% maturity to the grain yield. Therefore, while making selection these characters would be reliable criteria for improving grain yield of upland rice genotypes at southwestern Ethiopia.

Keywords: Direct and Indirect effect, Positive and negative correlation, Yield component traits