半夏叶斑病病原菌的鉴定、生物学特性及其有效杀菌剂研究

Identification,Biological Characteristics and Fungicide Screening of the Pathogen of Leaf Spot Disease in Pinellia ternata

目的:对半夏主产区叶斑病进行调查,明确各地叶斑病主要病原菌种类,同时结合生物学特性测定和室内杀菌剂筛选,为半夏叶斑病的防治提供参考。方法:在2020年6~9月,对贵州、河北、甘肃半夏种植区叶斑病进行调查,对致病菌进行分离、回接验证、形态和分子鉴定、生物学特性检测,同时采用平板抑菌实验进行杀菌剂的筛选。结果:引起3种叶斑病的致病菌分别为高粱附球菌Epicoccum sorghinum、南瓜孢子菌Stagonosporopsis cucurbitacearum、茄链格孢Alternaria solani。3种病原菌在温度为25~28℃、pH为弱碱性时适应性较好;菌株E.sorghinum生长不受光照条件的影响,菌株S.cucurbitacearum有光照时生长速率较快,菌株A.solani在24 h暗培养条件下生长迅速。室内药剂筛选结果表明,枯草芽孢杆菌对3种叶斑病菌均有较好的抑制效果,其次为苯醚甲环唑,植物源乙蒜素抑菌效果较差。结论:半夏叶斑病可由多种病原菌引起,室内条件下枯草芽孢杆菌、苯醚甲环唑对本研究筛选到的3株优势致病菌有较好的防治效果,可为半夏叶斑病的田间防控提供一定的依据。

Objective:To investigate leaf spot disease in the main production areas of Pinellia ternata,identify the main pathogenic bacteria species of leaf spot disease in different regions,so as to provide reference for the prevention and control of Pinellia ternata leaf spot disease in combination with the determination of biological characteristics and screening of indoor fungicides.Methods:From June to September 2020,leaf spot diseases in Pinellia ternata planting areas in Guizhou,Hebei and Gansu were investigated.The pathogenic bacteria were isolated,tieback verified,morphological and molecular identified,biological characteristics detected,and plate bacteriostatic test was used to screen fungicides.Results:The three leaf spot pathogens were Epicoccum sorghinum,Stagonosporopsis cucurbitacearum and Alternaria solani.The three pathogens had better adaptability when the temperature was 25 to 28℃ and the pH was weakly alkaline.The growth of Epicoccum sorghinum strain was not affected by light conditions,Stagonosporopsis cucurbitacearum strain grew faster under light conditions,Alternaria solani strain grew faster under 24 hours dark culture conditions.The results of indoor fungicides screening showed that Bacillus subtilis had a good inhibitory effect on the three leaf spot bacteria,followed by difenoconazole,and botanical fungicide ethylicin had a poor inhibitory effect.Conclusion:Pinellia ternata leaf spot can be caused by a variety of pathogens.Bacillus subtilis and difenoconazole have better control effect on the three dominant pathogenic bacteria screened in this study under indoor conditions,which can provide certain basis for field prevention and control of Pinellia ternata leaf spot disease.