间作豇豆对苹果幼树枝条部分生理指标及其抗寒性的影响

Effects of intercropping with cowpea(Vigna unguiculata L.Walp) on physiological parameters and frost hardiness of young apple tree

以连续3年间作豇豆(Vigna unguiculata L.Walp)的3年生‘天红2号’(Malus domestica‘Tianhong2’)红富士苹果1年生枝条为试材,连续3年清耕的同龄苹果树1年生枝条为对照,用电导法(EL)测定其抗寒性,并对枝条中可溶性糖、淀粉、可溶性蛋白等生理指标进行了测定比较,同时对间作果园树体的部分树相指标进行了调查,以期探明间作对苹果幼树抗寒性的影响,为苹果幼龄果园的科学间作提供理论依据。结果表明:隆冬时期及萌芽前,间作园树体抗寒性均低于对照,并达极显著水平。间作园苹果枝条中的可溶性糖、可溶性蛋白含量在2个时期均显著低于对照,淀粉含量在隆冬时期显著低于对照,至萌芽前则无明显差异。相关分析表明,两时期枝条中的可溶性蛋白、可溶性糖与其半致死温度呈显著负相关(r=-0.908～-0.992),而淀粉含量在隆冬时与枝条的半致死温度呈负相关,萌芽前则无显著相关性。间作果园1年生枝条中直立枝比例显著高于清耕园,超长枝的枝条长度及秋梢长度也显著大于清耕园,而枝粗则显著小于清耕园。

The effects of intercropping with cowpea （Vigna unguiculata L. Walp） for 3 years on cold hardiness of shoots of 3-year-old apple trees and some indexes of tree structure for young apple trees were studied, with clean cultivation as control. The results showed that the cold hardiness of apple trees in the apple-cowpea intercropping system was significantly lower than that of the pure apple tree stand during the winter and before sprout （P〈0.01）. The physio- logical parameters including soluble sugar, starch and soluble protein were assayed. The re- suits showed that the soluble sugar and soluble protein contents in one-year-old apple shoots which intercropped with cowpea were significantly lower than those in the control in the two periods （P〈0.05）, and the starch content was lower in the midwinter （P〈0.05） but no sig- nificant difference before sprout. Correlation analysis showed that the soluble sugar and solubleprotein contents were negatively correlated with the semilethal temperature of apple shoots in the midwinter and before sprout （r=-0. 908--0. 992）. There was a negative correlation be- tween the content of starch and the semilethal temperature in the midwinter （r=-0. 913）, but no correlation was found before sprout （P〉0.05）. Compared with clean cultivation, the ratio of the vertical long shoots in intercropping system was significantly higher, and the average length of super long shoots and the autumn shoots were much longer, but the diameter of the super long branch was much smaller.