低温胁迫下美国核桃和中国新疆核桃抗寒性综合评价

Comprehensive Evaluation of Cold Resistance of American Walnut and China Xinjiang Walnut under Low Temperature Stress

【目的】鉴定和综合评价美国核桃和中国新疆主栽核桃品种的抗寒性,为核桃品种的引进栽培提供科学参考。【方法】以5个美国核桃品种和3个中国新疆主栽核桃品种的一年生休眠枝条为试验材料,分别在-12、-16、-20、-24、-28、-32、-36℃下进行低温胁迫处理,以4℃处理为对照,测定不同低温胁迫下供试各品种的相对电导率、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量和丙二醛(MDA)含量,并进行相关性和主成分分析,运用隶属函数法对核桃各品种的抗寒性进行综合评价。【结果】随着处理温度的降低,核桃各品种一年生枝条相对电导率、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量和MDA含量逐渐升高,升高幅度及达到峰值时的处理温度有着明显差异,核桃各品种抗寒性强弱也不同。【结论】8个核桃品种抗寒性由强至弱依次为新温185、维纳、新丰、新新2号、艾米格、强特勒、哈特利、彼得罗,美国核桃品种除维纳外,抗寒性明显低于中国新疆主栽核桃品种,哈特利和彼得罗不适宜在中国新疆引种栽培。

[ Objective] To identify and evaluate the cold resistance of American walnut and Xinjiang wal-nut cultivars and to provide scientific reference for the introduction and cultivation of walnut varieties.[ M eth- od]The one year - old dormant shoots of 5 American walnut cultivars and 3 main walnut cultivars in Xinjiang were used as experimental materials, and they were treated under different cold stress conditions （ - 12℃ , -16℃ , -20℃ , -24℃ , -28℃ , -32℃ and -36 ℃ ） with the treatment under 4℃ as the control. The relative electric conductivity, soluble sugar content, soluble protein content, free proline content and malondi- aldehyde （MDA） content of the tested varieties under different low temperature stress were measured. What was more, the correlation and principal component analysis were used to evaluate the cold resistance of walnut varieties by means of subordinate function.[ Result]The results showed that with the decrease of temperature, the relative conductivity, soluble sugar, soluble protein, free proline and MDA contents of annual branches in-creased gradually. There was a significant difference between the rising range of each index and the peak tem-perature and different varieties had different cold hardiness.[ Conclusion] Comprehensive evaluation showed hat the cold resistance order of 8 walnut varieties was Xinwen 185 〉 Wina 〉 Xinfeng 〉 Xinxin 2 〉 Emig 〉 Chandler 〉 Hartley 〉 Pedro. Except for Wiener, the cold resistance of American walnut varieties is lower than that of Xinjiang walnut cultivars. ‘Hartley’and Pedro’are not suitable for cultivation in Xinjiang.