Genetic Path Coefficient Analysis of Genotypes of Rice (Oryza sativa L.) Grown in Iraqi Conditions

Abstract

Rice is one of the main and pivotal grain crops that feed more than half of the world’s population, due to the increasing population, food shortage has become a real problem. Amid the study them to find out the direct and indirect effects of the studied traits on grain yield by path coefficient analysis. Twenty-two genotypes planted during the summer agricultural season of 2021 at the Rice Research Station in Al-Mishkhab, 20 km south of Najaf province. A randomized complete block design (RCBD) was used with three replicates. The results of the mean squares of the genotypes were significant for all the studied traits at the 1% probability level. A positive significant correlation showed between the grain yield, the length of the deltoid, the number of branches in the panicles and the number of panicles grains (0.566, 0.513 and 0.503), respectively, while, it was not significant with the weight of 1000 grains (0.051). The genetic path analysis indicated to the direct effect of the length of panicles on the grain yield was high (0.413), while it was moderate with the number of branches in the panicle (0.206), and neglected with the number of grains per plant and the weight of 1000 grain (0.056, -0.040) respectively. Therefore, the traits of the length of panicles can be considered the best criteria for its adoption as a selection index for the yield of grains to give it the strongest positive correlation and the highest direct effect on the grain yield among the studied traits.