Screening of high temperature resistant strains of rice during heading and flowering period

In order to know the high temperature resistance of R6258，Rgu-1 and other new recovery varieties during heading and flowering period，we studied the seed setting rate of new rice lines under the condition of abnormal high temperature during heading and flowering stage，by high temperature resistance identification technology. The results showed that after treatment for 11 d at more than 35℃ in flowering stage ，there were significant differences in seed setting rate among rice varieties and among lines. For standard resistance parameter，there was the order of RHTs Ⅱ you 838，Rgu-1，R6258，R362，Rdong 005，Jinyougui 99，R21-1；for the competition resistance parameters，there was the order of RHTC Ⅱ you 838，Rgu-1，R6258，R362，Rdong 005，R21-1，Jinyougui 99. The seed setting rate of Rgu-1 and R6258 was not significantly different from Ⅱ you 838，while significantly higher than that of Jinyougui 99. The resistance parameters of Rgu-1 were 0.801 and 0.976，of R6258 were 0.788 and 0.947， were similar to these of Ⅱ you 838（ 0.808 and 1），indicating that Rgu-1 and R6258 had strong resistance to high temperature during heading and flowering period. Rice line Rgu-1 and R6258 can be used as resistant germplasm resources for breeding resistant rice varieties.