Identification of Cold Tolerance of Rice Germplasm Resource at Germinating Stage in Cold Region

Total 75 rice varieties (lines) in Heilongiiang Province (or cold region) as germplasm resources were identified for cold tolerance at germinating stage by controlling temperature in artificial incubator. The results showed that the shooting seed rate at the germinating stage could be used as the evaluation index of cold tolerance. The cold tolerance was recorded on 1-9 scale and could be identified by the criteria of five indexes such as highly tolerant (HT), tolerant (T), moderately tolerant (MT), susceptible (S), highly susceptible (HS).