【作者】 王文娟；

【导师】 赵建庄； 路苹；

【作者基本信息】 北京农学院 ， 果树学， 2008， 硕士

【摘要】 苹果斑点落叶病是影响苹果产量和品质的重要病害。当前,有关对苹果斑点落叶病的研究,仅局限在对病原菌生物学特性以及利用化学手段防治病害方面的研究。鉴于诱导抗病性的研究进展与植物激活剂的特点,本文以苯并噻二唑(Benzothiadiazole,BTH)为诱导因子,以苹果树和斑点落叶病菌(Alternaira alternata f.sp.mali)为研究对象,研究诱导剂在不同浓度下对抗苹果斑点落叶病的诱导作用、诱导抗病的持效期、组织病理学特征以及生理生化机制。其中,生理生化机制主要研究诱导抗病性与苯丙氨酸解氨酶(PAL)活性、几丁质酶活性、β-1,3-葡聚糖酶活性、木质素和富含羟脯氨酸糖蛋白(HRGP)含量的关系。采用常规组织分离法分离纯化苹果斑点落叶病菌,病原形态观察和人工回接试验鉴定病原菌。BTH诱导苹果主枝顶梢,整株接种病原菌后,采用病情指数统计发病程度。用整叶组织透明染色法进行组织病理学观察,用比色法测定PAL、几丁质酶、β-1,3-葡聚糖酶活性以及木质素和HRGP含量的变化。PDA培养基测定不同浓度BTH离体抑菌活性。结果表明:BTH能诱导苹果树产生系统获得性抗性,当诱导浓度为150μg·mL-1时,可使病情指数由对照的26.34下降到16.87,抗病持效期可达15d,其中最佳诱导时间为处理后3～6d,而BTH本身对苹果斑点落叶病菌分生孢子萌发及菌丝生长无明显影响。组织病理学观察发现,BTH诱导抑制病菌侵染钉的形成,限制病菌向细胞内扩展;生理生化指标测定表明,BTH诱导能提高苹果叶片PAL、几丁质酶、β-1,3-葡聚糖酶活性以及木质素和HRGP的含量。BTH处理的果苗防卫反应启动早于对照果苗。更多还原

【Abstract】 Alternaira alternata f.sp.mali (AAM) is a most important epidemic disease that threatens the yield and quality of apple production. Currently, the research about AAM is just around biological character of pathogen and the chemical prevention of the disease. Considering the advance of research on induced disease resistance and the characteristic of plant activator, the effects of resistance induced by benzothiadiazole (BTH) at different concentrations against AAM in apple were investigated. The duration of induced disease resistance were studied. Moreover the histopathological mechanism and physiological mechanism were researched. The physiological mechanism comprised the relationship of BTH induced disease resistence with the contents of hydroxyproline-rich glycoprotein (HRGP) and Lignin, with the activity of phenylalanine ammonialyase (PAL), chitinase andβ-1, 3-glucanase.The AAM was isolated and purified from infected apple leaves by tissue isolating method. The conidiophores and mycelia structure of the pathogen were observed by microscope. The pathogenic power was investigated by leaf in vitro inoculation. Apples were inoculated with spores of AAM after applying BTH as a foliar spray to peak branch and disease index was investigated. The histopathological response was investigated with whole leaf clearing and staining technique. The activities of enzyme and the contents of Lignin and HRGP were measured with colorimetric method. The inhibitory effects of different concentration BTH against AAM on potato dextrose agar were studied.The result showed that application of BTH at different concentrations on apple leaves had significant effect to restrain AAM. The effect of 150μg·mL-1 was distinctly better than others, and it could reduce the disease index from 26.34 to 16.87. In addition, the induced disease resistance could last more than 15 days, but the best induced times were 3～6 days after 150μg·mL-1 BTH treatment. However, conidiophores germination and mycelia growth were not restricted by BTH itself. The penetration pegs’formation of pathogen was inhibited, and then pathogen extending was restricted. The activities of PAL, chitinase andβ-1, 3-glucanase of apple leaf rised after BTH inducement. Moreover, the contents of Lignin and HRGP of apple leaf increased too. So the defendable reaction of induced apple trees was started earlier than control.更多还原