新疆南疆核桃叶缘焦枯病成因分析研究

Study on Causation of Walnut Withered Leaf Symptom in Southern Xinjiang

[目的]研究新疆南疆核桃叶片边缘焦枯症状的发生原因。[方法]应用对比研究法,在和田地区和喀什地区选择叶缘焦枯病严重的核桃树为研究对象,以健康生长的核桃树为对照,多点分别采集叶片和根区土壤样品,测定元素含量,统计分析病树与健康树元素含量及比值的差异,结合当地土壤水土状况判断核桃叶缘焦枯病的形成原因。[结果](1)经过比较核桃叶片中N、K、Ca、Na、Cl、Na/K、Na/Ca、Cl/N发现,发病树体叶片中Cl^-和钠离子含量显著高于正常树体,有叶缘焦枯病症状叶片边缘Cl^-和Na^+显著高于叶芯,而钙离子含量下降。发病叶片离子之间比例失衡,Cl^-/N、Na^+/K^+、Na/Ca比值较正常叶片显著升高。(2)发生叶缘焦枯病的核桃根区土壤中Cl^-、Na^+含量高于未发病核桃树根区土壤。[结论]核桃叶缘焦枯症的发生与叶片中Na^+、Cl^-的富集有关,发病区域土壤Cl^-含量偏高。

[Objective]This project aimed to study the causation of walnut wihtered leaves symptom (WWLS) in southern Xinjiang.[Method]Hetian and Kashi were chosen as the sampling dots,where the walnut withered leaf symptom is serious,and it has broken away the edge and center of walnut leaves.The element contents of the two areas were mensurated and compared with the normal leaves.The difference between element contents and ratios of the different parts were counted and analyzed,by which,the status of local water and soil was estimated to judge the causation of WWLS.[Result](1 )The result showed that,by comparing the content of N,K,Ca,Na,Cl,Na/K,Na/ Ca,Cl/N in leaves which were regarded bad and normal leaves,the content of the elements in bad leaves was unbalanced,especially the content of chlorin ion and the natrium ion was remarkably higher than normal leaves,and that the content of chlorin ion and the r atrium ion was higher in the edge than in the center of bad leaves,but the calcium ion was less in the edge than in the center.(2) Furthermore,the content of chlorin ion and natrium ion in WWLS soil was higher than the normal.[Conclusion]The causation of WWLS was related to enrichment of chlorin ion and natrium ion in leaves,and the content of chlorin in soil where the WWLS developed in walnut trees is higher.