枣疯病病树中内源激素的变化研究

The Variations of Endogenous Hormones in Chinese Jujube Infected with Witches' Broom Disease

【目的】揭示枣疯植原体对枣树内源激素的影响,弄清枣疯病病树中内源激素的变化趋势。【方法】应用HPLC法分别对健株、病株和盐酸土霉素治疗后转健植株中的细胞分裂素(玉米素,Zeatin)、生长素(吲哚乙酸,IAA)、赤霉素(GA3)和脱落酸(ABA)的含量进亚周年检测。【结果】在根部,健株、治疗株和病株中IAA、GA3和ABA的含量没有明显区别,但在7、8月份病株根部中Zeatin的含量要明显高于健株;在叶部,健株、治疗株和病株中的IAA、GA3和ABA的含量也没有明显区别,但在生长后期病株叶片中Zeatin含量显著高于健株。不同患病程度叶片中激素的比较结果表明,患病程度越重,Zeatin/IAA(C/A)比值越高。【结论】植原体侵染枣树植株后致使其内源激素失衡,主要是细胞分裂素含量的增加,最终导致了枣疯病症状表现。

[Objective] Jujube witches＇ broom （JWB）, caused by phytoplasma, is the most serious and destructive disease of Chinese jujube （Ziziphus jujuba Mill.）. This study was done to reveal the influence of phytoplasma on the endogenous hormones of Chinese jujube, and to make clear the variations of the endogenous hormones in the root and leaf of a tree after they have been infected with JWB. [Method] The contents and variations of Zeatin, IAA, GA3 and ABA in healthy tree, diseased tree and the diseased tree cured with oxytetracycline were measured nearly a whole year by HPLC. [Result] In roots, there were no difference in the contents of IAA, GA3 and ABA among healthy, diseased and cured trees, but obvious difference in the content of Zeatin between diseased （high） and healthy tree in July and August. In leaves, there were also no difference in the contents of IAA, GA3 and ABA among healthy, cured and diseased jujube, but the content of Zeatin of diseased jujube increased continuously and was higher obviously than that of healthy one in the later stage. Comparison among trees with different disease extent showed that the heavier the disease extent, the higher the Zeatin/IAA （C/A）. [ Conclusion] The infection of phytoplasma could cause the imbalance of the endogenous hormone （Zeatin increased significantly and resulted in the witches＇ broom symptom）.