SCREENING AND IDENTIFICATION OF RICE GERMPLASMS WITH COLD-RISISTANCE AT SEEDLING STAGE

13 rice germplasm displaying cold resistance at seedling stage including 3 Indica varieties and 10 Japonica varieties have been identified from 84 varieties in Micro-core Rice Collection screened by natural low temperature.Further cold treatment in climate chamber showed that cold resistance of above 13 rice germplasms reached level of 1 to 4,of which Japonica 87-304 reached level 1 under continuous low temperature treatment.In altered low temperature condition,the leaves of cold sensitive varieties Sanbaili and Jiabala were scorched and died gradually after recovery to room temperature,but leaves of cold resistant varieties Guihuahuang and Sujiang 2 were not scorched distinctly.The extent of leaf curling and chlorophyll fading under cold stress within a comparatively short period could be applied as an efficient index for identification of cold resistance during seedling stage.The research provides novel rice germplasm for cold resistance breeding and a basis for cloning cold resistance genes in rice.