Abstract: Buckwheat is the major food crop in high altitude areas such as Liangshan district, Sichuan province, China. In order to explore the cold resistance of buckwheat and screen excellent buckwheat germplasm resources adapted to Liangshan district, 5 common buckwheat (Fagopyrum esculentum Moench.) and 13 Tartary buckwheat [Fagopyrum tataricum (L.) Gaertn. ], the most extensive varieties and landrace, were used to evaluate the cold resistance during seed germination stage at 4℃(low temperature condition) and 22℃(control condition). Seven indices related to germination and growth were measured, including radicle length, germination rate and germination potential. Comprehensive cold resistance was reflected by subordinate function analysis, principal component analysis and cluster analysis. The results showed that under low temperature conditions, the seed germination of all buckwheat materials was delayed and the germination rate was retarded. Compared with Tartary buckwheat, seven germination and growth indexes of common buckwheat maintained a higher level, indicating that common buckwheat was more tolerant under low temperature environment. The comprehensive evaluation of the membership function results suggested that Jiuzhaigou common buckwheat had the strongest low temperature tolerance ability at the germination stage, followed by Pintian No.3, whereas Xiqiao No.6 was the most sensitive to low temperature.

Key words: Liangshan, Buckwheat, Low temperature germination, Cold resistance, Comprehensive evaluation