低温胁迫对核桃枝条几个抗寒生理指标的影响

目的]筛选出与核桃枝条抗寒力相关的生理指标.方法]采用人工模拟低温处理,对低温胁迫下一年生核桃枝条的半致死温LT50、SOD活性、CAT活性、POD活性、MDA含量、可溶性糖含量、游离脯氨酸含量的变化进行了测定和分析.结果]一年生核桃枝条的半致死温为- 24.69℃.随着低温胁迫的加剧,核桃枝条的电解质渗出率、CAT活性、MDA含量及游离脯氨酸含量均表现出逐渐上升的趋势；SOD和POD活性表现出“低-高-低”的趋势；可溶性糖含量表现出先下降后上升的变化趋势；CAT活性、MDA含量和游离脯氨酸含量与相对电导率变化显著相关.结论]相对电导率、CAT活性、MDA含量和游离脯氨酸含量可作为核桃抗寒力评价的关键指标.

Influence of Low Temperature Stress on Several Cold Resistance Indexes of the Primary Branches of Walnuts

Objective]The purpose of this project was t select correlated key physiology indexes for evaluating cold resistance of the primary branches of walnuts.Method]Artificial low temperature treatment was used to measure and analyze the changes of LT_(50),SOD activity,CAT activity,POD activity,MDA content,soluble sugar content and proline content of the primary branches of walnuts.Result]LT_(50) of the primary branches of walnuts were -24.69℃.When low temperature stress was intensified,electrolyte leakage,CAT activity,MDA content and proline content were increased,while SOD activity and POD activity increased at first,then decreased,and increased at last;Soluble sugar content decreased at first,then increased;Significant correlation was showed among CAT activity,MDA content,proline content and relative conductance.Conclusion]Relative conductance,CAT activity,MDA content and proline content could be used as the key physiology indexes for evaluating the cold resistance of the primary branches of walnuts.