不同小麦品种对低温胁迫的反应及抗冻性评价

以济麦19、济麦21、济南17等15个冬小麦品种为材料,对其在低温胁迫条件下功能叶和叶鞘超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量与可溶性蛋白含量等生理指标进行测定,以功能叶各项指标的抗冻系数作为衡量抗冻性的指标,利用主成分分析、聚类分析对其抗冻性进行综合评价。低温胁迫条件下,不同冬小麦品种起身拔节期功能叶和叶鞘中SOD活性、POD活性和CAT活性均不同程度地上升,MDA含量和可溶性蛋白含量均下降。通过主成分分析和聚类分析,将15个冬小麦品种划分为3类:济麦19、山农8355属强抗冻类型;山农664、泰山9818、济麦21、济麦22、烟农24、烟农19、烟农21、汶农6号、鲁麦21、济南17属中度抗冻类型;其余3个品种(泰山23、聊麦18、临麦2号)属弱抗冻类型。

Evaluation of wheat freezing resistance based on the responses of the physiological indices to low temperature stress

Freeze injury is one of the major disasters for the production of winter wheat in the North China Plain. Wheat in the stem elongation period is very sensitive to the large fluctuation of air temperature, which often occurs in spring. Low temperature of the early spring frost in north China plain is very harmful to the growth of winter wheat, leading to a significant decrease of wheat yield. Therefore, the effective evaluation of the freeze resistance of the different wheat cultivars is necessary for the proper choice of suitable cultivars in production and, in turn, for the achievement of the stable higher yield of wheat.The experiment was conducted at Tai'an Experimental Station of Shandong Agricultural University with fifteen wheat cultivars. The superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, MDA content, the soluble protein content of fifteen winter wheat cultivars were measured as physiological indices for evaluating the freeze resistance. It was found that the responses of these physiological indices to low temperature treatments were quite different among wheat cultivars. The comprehensive evaluation of wheat freeze resistance coefficient of SOD activity, POD activity, CAT activity, MDA content, the soluble protein content of fifteen wheat cultivars were conducted with principal components analysis and cluster analysis. The results indicated that under low temperature stress, the activities of SOD, CAT, and POD increased and the content of MDA and the soluble protein decreased in functional leaves and sheath of each cultivar in stem elongation period. Based on the changes of the physiological indices in response to low temperature stress and the cluster analysis the fifteen winter wheat cultivars were divided into three groups, namely high, medium, and low freeze resistance cultivar group. Jimai19 and Shannong8355 belong to high freezing resistance group; The medium freeze resistance group covers Shannong664, Taishan9818, Jimai21, Jimai22, Yannong24, Yannong19, Yannong21, Wennong6, Lumai21, and Jinan17; the others three cultivars, Taishan23, Liaomai18, and Linmai2 belong to low freezing resistance group. This classification of wheat cultivars in freeze resistance is very useful for the proper choice of the suitable wheat cultivars in order to decrease or avoid the damage from spring freeze in wheat production in the North China Plain.