The Study of Correlation and Path Analysis of Grain Yield and its Related Traits in Rice (Oryza sativa L.) Varieties and Lines

In order to assessment of relationships between effective traits on grain yield and also determination of cause and effect relationships between of them, 121 native and exotic cultivars available in the collection of Rice Research Institute of Iran were evaluated in a simple lattice design (11×11) with two replications for 12 important agronomic traits. The results of analysis of variance showed a significant difference between studied genotypes for all traits at the 0.01 probability level. Phenotypic and genotypic coefficients of variation for most traits were high, indicating high variability in studied genotypes for evaluated traits. Simple correlation coefficients between traits showed that 100-grain weight, number of filled and unfilled grain per panicle, number of tiller and also leaf length and width traits have a significant correlation with grain yield. In multiple regression analysis by stepwise method, 100-grain weight, number of tiller, leaf length, number of filled grain per panicle and leaf width traits were entered into model, respectively, that explained 81 percent of grain yield variations. Also based on path analysis results, 100-grain weight (1.411) and number of filled grain per panicle (1.254) traits have the most and positive direct effect with grain yield and thus, these traits could be considered as selection criteria for grain yield improvement in rice.