美人蕉叶斑病病原菌的生物学特性及其抑菌药剂筛选

Biological Characterization and Screening of Fungicides on Canna indica Leaf Spot Disease Pathogen

为明确美人蕉叶斑病病原菌（Alternaria alternata）的生物学特性以及筛选最适常用药剂,为美人蕉叶斑病的防治提供科学依据。对引起美人蕉叶斑病的病原菌进行生物学特性观察,并对其进行室内药剂筛选。结果表明：该病原菌菌丝生长的最适温度为28℃,致死温度为45℃,碳源和氮源分别以蔗糖和硝酸钠为佳,在pH为3~10的范围内均能生长,生长最适pH为7,光照条件和通气状况对菌丝生长没有明显影响。在供试的5种药剂中,10%苯醚甲环唑效果最好,在推荐的使用浓度下相对抑菌率达到100%。

In order to elucidate the biological characteristics and suitable fungicide for the pathogen of canna leaf spot Alternaria alternate,provide a scientific basis for the disease control.The biological characters of Alternaria alternata,the pathogen of Canna indica leaf spot,as well as the fungicides against the pathogen were investigated in this paper.The results indicated that the pathogen hyphe were grown well under 28℃,pH=7,sugar and NaNO3 as carbon and nitrogen resource respectively.The lethal temperature was 45℃.On the other hand,the light-dark alternation and aeration condition were not significant influence on the mycelium growth.The most effective fungicide was 10% difenoconazole among the 5 tested reagents,and the relative inhibition rate was 100% under the recommended concentration.