关键词: 早实核桃, 抗寒性, 生理生化指标, 综合评价

Abstract: Nine early fruiting walnut cultivars were used as the test materials to determinate the effect of low temperature stress to the young sprout using the indexes such as relative conductivity，soluble protein，soluble sugar，proline，superoxide dismutase（SOD）activity，peroxidase（POD）activity and catalase（CAT）activity in artificial simulation low temperature environment. Taking cold resistant coefficient of each physiological index of walnut leaves as index to measure cold resistance capacity，and cold resistance of early fruiting walnut cultivars were comprehensively evaluated by using principal components analysis，membership function and cluster analysis based on cold resistant coefficient of these indexes. The sequence of cold resistance of nine early fruiting walnut cultivars was：Liaoning 4 > Chandler > Zha 343 > Xiangling > Xilin 2 > Xifu 2 > Xilin 3 > Liaoning 3 > Luguang. Liaoning 4 and Chandler belong to high cold resistance group；The medium cold resistance group covers Zha 343，Xiangling and Xilin 2，the others four cultivars，Xifu 2，Xilin 3，Liaoning 3 and Luguang belong to low cold resistance group. The comprehensive evaluation results is similar to results observed in morphological characteristics of shoots.

Key words: early fruiting walnut, cold resistance, physiological and biochemical indexes, comprehensive evaluation