以6个红枣品种临泽小枣、俊优2号、脆枣、骏枣、爆米花和子弹头的1年生枝条为试材，测定相对电导率、可溶性糖、可溶性蛋白、丙二醛、游离脯氨酸含量等指标，研究其在低温处理下的生理变化特征，并用主成分分析法对其抗寒性进行综合评价。结果表明，6个品种枣树的半致死温度值(LT50)为-23.73～-16.06 ℃，俊优2号的最低、子弹头的最高。不同红枣品种的生理指标变化趋势具有较强的规律性，随温度的降低，相对电导率和丙二醛含量呈上升趋势，可溶性糖、可溶性蛋白及游离脯氨酸含量先升高后降低。用 Logistic 方程拟合求出的各供试砧木低温半致死温度(LT50)及主成分分析结果均显示，不同品种红枣枝条的抗寒性差异较大，抗寒性由强到弱依次为俊优2号、临泽小枣、 脆枣、爆米花、骏枣、子弹头。

Using one-year-old branches of 6 red date varieties from Linzexiaozao， Junyou No. 2， Crisp jujubeCrispy date， Junzao， pPopcorn jujube and one-year-old branches of Bbullet varietys， as test materials， the relative conductivity， soluble sugar， soluble protein， malondialdehyde and free proline contents arewere determined. The content of proline and other indicators were used to study its physiological change characteristics under low temperature treatment， and its cold resistance was comprehensively evaluated by principal component analysis. The results showed that the half-lethal temperature (LT50) of the 6 varieties of jujube trees was -23.73～-16.06 ℃， among which Junyou 2 had the lowest and the highest bullet. The change trend of physiological indicators of different red jujube varieties has a strong regularity. With the decrease of temperature， the relative conductivity and malondialdehyde content increased， while the contents of soluble sugar， soluble protein and free proline increased first and then decreased.the relative conductivity and the content of malondialdehyde show an upward trend. The content of soluble sugar， soluble protein and free proline increases first and then decreases. The results of Logistic equation fitting and principal component analysis showed that the cold resistance of branches of different red jujube cultivars differed greatly， and the cold resistance was he low-temperature semi-lethal temperature(LT50) and principal component analysis results of the tested rootstocks calculated by the Logistic equation fitting show that the cold resistance of different varieties of red jujube branches is quite different，Junyou No. 2， Linze xiaozaoLinze jujube， Ccrisp jujube， pPopcorn jujubeopcorn， Jun jujube， Bullet variety， bullet from strongest to weakest respectively.

S665.1

甘肃省科技计划项目(18CX3FG021)。