为建立葡萄抗寒性的综合评价方法,以7个葡萄品种的枝条为试材,通过人工模拟低温的方法,分别于10、-5、-15、-25、-35、-45℃下处理葡萄枝条,测定枝条可溶性糖、可溶性蛋白、丙二醛、游离脯氨酸、组织含水量、相对电导率等抗寒相关指标,根据抗寒性指标在低温处理过程中的变化,确定葡萄枝条抗寒性指标的有效低温适用范围。并以相对电导率结合Logistic方程计算葡萄枝条的半致死温度(LT50),以LT50为葡萄抗寒能力的衡量指标,用相关分析法确定评价葡萄抗寒性的5个主要相关指标。用主成分分析法将5个指标转化为综合的主成分,确定指标权重,并结合隶属函数法建立葡萄抗寒的评价方法,运用隶属度函数值求得各葡萄抗寒性的综合评价指数Y。根据综合指数判断抗寒性强弱顺序为:双优〉左优红〉北冰红〉贝达〉5BB〉5C〉黑比诺。结果表明:葡萄枝条可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量、丙二醛含量、相对电导率等与葡萄抗寒性有极显著或显著相关关系,因此,运用主成分分析法结合隶属度函数法,来综合评价葡萄的抗寒性将更加准确、科学。
To establish a comprehensive assessment method for cold resistance of grapes,branches from seven grape cultivars were exposed to different temperatures(10,-5,-15,-25,-35,-45℃).After exposure,cold resistance-related indices,including soluble sugar content,soluble protein content,malondialdehyde(MDA)content,free proline content,water content and relative electric conductivity,were measured.The most efficient temperature range for determining cold resistance-related indexes was decided by assessing changes indices after low temperature exposure.Semi lethal temperature(LT50)was calculated using relative electric conductivity.The LT50 was used to assess cold resistance indices using correlation analysis.The cold resistance indices were then subjected to principal component analysis.A comprehensive method for assessing cold resistance in grapes was established using a membership function method.The cold resistance of cultivars was found to vary:Shuangyou〉Zuoyouhong〉Beibinghong〉Beda〉5BB〉5C〉Pinot noir.Our results indicated that soluble sugar content,soluble protein content,free proline content,MDA content and relative electric conductivity were significantly correlated with cold resistance in these grape cultivars.Principal component analysis combined with membership function analysis was useful for evaluating cold resistance in grapes.