Effect of high temperature at heading and flowering stage on seed-setting rate of rice recombinant inbreed line population (RIL47)

Rice recombinant inbreed line population RIL47 (comprising 254 lines) was treated with high and natural (CK) temperatures at heading and flowering stage and the effect of high temperature on seed-setting rates evaluated. The results indicated that seed-setting rate of RIL47 followed a normal distribution curve under natural conditions. Compared with natural temperature, high temperature significantly decreased RIL47 seed-setting rate with an average decline of 81.6%. Absolute decline in RIL47 seed-setting rate followed a normal distribution curve. Five heat-tolerant lines (07H1619, 1590, 1521, 1706 and 1608) and three heat-sensitive lines (07H1751, 1710 and 1719) were simultaneously selected from the 254 RIL47 lines by using a heat-injure index. This could be used in analyzing heat resistance of rice.