低温胁迫对金叶白蜡5个生理生化指标的影响

以金叶白蜡的1a生休眠枝条为试材、白蜡为对照，对不同温度下的相对电导率、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性及可溶性糖和可溶性蛋白含量进行研究。结果表明：随着胁迫温度的降低，金叶白蜡和白蜡的相对电导率均呈“S”型曲线上升；SOD和POD活性则呈先上升后下降的变化规律；可溶性糖和可溶性蛋白含量总体呈上升趋势。对所有指标进行相关性分析，并利用相对电导率结合Logistic方程进行拟合，结果表明：相对电导率、SOD活性、POD活性、可溶性糖含量和可溶性蛋白含量均可作为金叶白蜡的抗寒性鉴定指标；金叶白蜡和白蜡的半致死温度分别为-29．2℃和-32．3℃，金叶白蜡的抗寒性弱于白蜡。

Study on the cold resistance of Fraxinus chinensis ‘Jinguan＇

Using one-year-old dormant twigs of Fraxinus chinensis ‘Jinguan’as test materials and Fraxinus chinensis as control, relative electrical conductivity, activity of superoxide dis- mutase and peroxidase, and content of soluble sugar and soluble protein under different tem- perature were studied. The result showed that as the stress temperature decreses, the rela- tive conductivity of Fraxinus chinensi‘Jinguan’ and Fraxinus chinensis showed an S-type rise; SOD and POD ativity was increased and then decreased; soluble sugar and soluble pro- tein content had an overall upward trend. The correlation analysis of above indicators combined with the relative conductivity with the logistic equation fitting revealed that the indexes can be used as the identification indexes of cold resistance of Fraxinus chinensis ‘Jinguan’ ; the lethal tempera- ture of Fraxinus chinensis ‘Jinguan’ and Fraxinus chinensis was --29.2℃ and--32.3℃, with the cold resistance order of Fraxinus chinensis ‘Jinguan’ 〈 Fraxinus chinensis.