تعیین شاخص انتخاب برای بهبود عملکرد از طریق تجزیه علیت

This study was conducted to determine the association between grain yield and its components and identifying traits that have the greatest effect on grain yield of 42 rice lines (tolerant to heat stress from IRRI), plus variety Hoveyzeh as control, in a randomized complete block design with three replications. Stepwise regression method showed that tillers per sequare meter and number of seeds per spike explaied 68.42 and 76.34 percent of grain yield variation, respectively. Results of path analysis showed that the number of seeds per spike had highest direct effect and indirect effect via number of tillers per unit area on seed yield. So, the number of seeds per spike can be considered as a suitable selection index to evaluate different rice lines for increasing seed yield under climatic conditions of Khouzestan province.