[目的]研究香蕉叶斑病病原真菌种群结构的季节性变化,为香蕉叶斑病的流行学研究和防治提供理论依据.[方法]2009年6～10月,对南宁市金陵镇第1年生香蕉的真菌性叶斑病病原随机抽样,检测单个病斑的病原菌,并分析每个时期病原菌的种群结构.[结果]南宁市金陵镇香蕉真菌性叶斑病病原至少有9种,主要病原为香蕉暗双孢菌(Cordana musae).叶斑病类型以单一病原侵染为主,其独立侵染的检出率随着季节的变化呈先升后降趋势,最高峰(8月15目)达88.8％；复合侵染的叶斑病类型以两种病原共同侵染居多,检出率的变化趋势与单一病原相反；除Alternaria musae和Pestalotiopsis menezesiana外,其他7种病原之间可共同侵染香蕉；Cordana musae的总检出率呈振幅式上升,最高检出率达92.8％.[结论]季节变化是影响香蕉真菌性叶斑病病原种群结构的一个主要环境因子.Cordana musae是田间香蕉真菌性叶斑病病原菌的优势种,建议香蕉叶斑病的防治主要针对由Cordana musae引起的灰纹病.%[Objective]The present work was carried out to study the seasonal variation in population structure of banana mycotic leaf spot pathogen in order to provide information for its control. [Method]The effects of fungal pathogens, causing mycotic leaf spot diseases, were investigated on annual growth of banana plantations at Jinling Township (Nanning) from June to October, 2009. Pathogens of leaf spot were examined and the population structure was analyzed during each period. [Result]At least nine fungal pathogens of mycotic leaf spots of banana were observed, amongst which, the Cordana musae was the major pathogen. The single-pathogen-induced banana leaf spots (SBLS) were predominant. The detection rate of SBLS was slightly higher and declined rapidly along with seasonal variations, with the peak rate (88.8%) detected on 15 August. The co-infected banana leaf spots (CBLS) with two or more fungal pathogens showed opposite trends compared to SBLS. Except for Altemaria musae and Pestalotiopsis menezesiana, seven other fungal pathogens were found to infect banana plants. The total detection rate of C. Musae increased with highest value was 92.8%, however it did not showed any distinct trend. [Conclusion]Seasonal variations were one of the major factors effecting fungal pathogen population dynamics associated with banana leaf spot diseases. The C. Musae, inducing SBLS, was predominant during the period of banana growth. It was recommended to control gray line disease induced by C. Musae during control of banana mycotic leaf spot.
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