Abstract:Using 378 japonica rice germplasm resources from 14 foreign countries and 13 provinces of China, the dead leaf rate at the seedling stage under different alkaline stress was evaluated, and japonica rice germplasm resources with strong alkaline tolerance were selected. The results showed that the dead leaf rate under alkaline stress for pH9.4 was significantly larger than that under alkaline stress for pH 8.9, while alkaline stress for pH 8.9 was more suited to evaluate the dead leaf rate for japonica rice germplasm resources. The alkaline tolerance among different japonica rice germplasm resources from different geographical origins under alkaline stress for pH8.9 was significantly different. The japonica rice germplasm resources from Australia, Italy and Jiangxi province of China were appeared lower dead leaf rate, which had stronger alkaline tolerance than others. The dead leaf rate of tested materials during 16 days to 26 days under alkaline stress for pH8.9 were ranged from 20% to 100%, and which showed continuous distribution near normal with larger variance and coefficient of variation. So these period was considered fit to evaluate the alkaline tolerance for japonica rice germplasm resources. Twenty-one japonica rice germplasm resources, such as YR196, Baru, Fengjin, Nipponbare, 8068, Suijing 5 and so on with strong alkaline tolerance were selected, which showed stronger alkaline tolerance with less than 40% of the dead leaf rate when 16 days under alkaline stress for pH8.9. These rice germplasm resources could be applied for further rice alkaline tolerance breeding.