玉米纹枯病菌致病因子的研究

On Pathogenicity Factors in Maize Sheath Blight

首次研究了五米纹枯病菌（RhizoctoniasolaniAG1-IA）产生的细胞壁降解酶和毒素在病程中的作用。纹枯病菌主要产生PG、PMG和Cx共3种细胞壁降解酶和毒素．细胞壁降解酶和毒素对叶片和叶鞘有明显浸解作用，其中酶比毒素作用明显，但用单一酶或毒素代替病菌接种不同抗性品种，尚不能反映品种间抗性差异。病菌产生的细胞壁降解酶活性受温度、pH、反应时间和底物浓度等因素影响。

A series of cell wall degrading-enzymes (CWDEs) and toxins were produced from Rhizoctonia solani AG1 -IA which was the pathogen of maize sheath blight.Among others CWDEs, PG, PMG and Cx were determined as major ones. The major CWDEs and toxin showed a significant maceration to sheath cells but CWDEs appeared more virulent to the hoSt cells than toxin did. No obvious difference among cultivars with various resistance to the disease are found if host inoculation was done with single CWDE or toxin in replace of pathogen itself. The activities of CWDEs were influenced seriously by temperature, pH, reaction time and substrate concentration.