柳叶蜡梅真菌病害分离鉴定及生物学特性

The Pathogen Identification and Its Biological Characteristics of Chimonanthus salicifolius Leaf Spot Disease

为明确柳叶蜡梅(Chimonanthus salicifolius)的叶部病害的病原种类,进行病叶病原分离鉴定。本研究对福建省寿宁县福瑞泰生物技术有限责任公司种植基地的柳叶腊梅叶斑病病叶采用离体组织分离法进行分离,对分离的病原菌采用形态学结合分子方法(rDNA-ITS和TUB序列)进行鉴定,并对该致病菌菌丝体在不同温度、pH、光照、碳源、氮源及致死温度等条件下的生物学特性进行了研究。病原菌分离株经形态特征观测及rDNA-ITS和TUB序列分析比对,将寿宁县柳叶腊梅叶斑病病原菌分离株鉴定为半知菌门、丝孢纲、弯孢属、间型弯孢霉(Curvularia.intermedia)。生物学特性结果显示:此菌菌丝体生长最适生长温度为30℃、最适pH 8、最适碳源为葡萄糖、蔗糖及麦芽糖、最适氮源为硝酸钾、酵母粉及硝酸钠;光暗交替不影响菌丝生长;菌丝体致死温度为52℃。分离鉴定了福建省寿宁县柳叶腊梅叶斑病病害的主要病原菌是弯孢霉,其生物特性测定结果显示对环境适应性强。

The isolation,classification and biological characteristics of the pathogens of Chimonanthus salicifolius leaf diseases were studied.The suspected pathogens of leaf spot disease were isolated from the leaves of sick trees from Shouning County in Fujian Province with in vitro tissue culture method.The fungal pathogens were isolated and classified by colonies,spore morphology identification,and rDNA-ITS and TUB sequence analysis.The biological characteristics and optimal growth conditions of mycelia including temperature,pH value,light,carbon source,nitrogen source,and lethal temperature were explored.Based on the colonies,conidiophore morphology,and rDNA-ITS and TUB sequence alignment,the isolated fungal pathogen was classified into Deuteromycotina,Basidiomycetes,Curvularia,Curvularia intermedia.The studies on the biological characteristics and growth conditions of mycelia indicate that the optimal growth temperature is 30℃,the optimum pH is 8;the best carbon sources are glucose,sucrose and maltose;the most preferred nitrogen sources are potassium nitrate,yeast powder and sodium nitrate;the alternations of light and dark conditions could not affect the growth;and the lethal temperature is 52℃.In summary,the major pathogen of leaf spot disease of Chimonanthus salicifolius from Shouning County in Fujian Province is Curvularia intermedia,which possesses high resistances,strong growth activities,and severe pathogenicity in the environment.