柳叶白前白绢病病原菌的鉴定、生物学特性及其有效杀菌剂研究

Identification,biological characteristics and fungicide screening of pathogen of southern blight in Cynanchum stauntonii

湖北省团风县柳叶白前种植区在2017—2019年6—10月的高温多雨季节,田间暴发了严重的白绢病,对药材产量和质量造成较大影响。为明确柳叶白前白绢病病原真菌,该研究按照柯赫法则对其病原菌进行分离、纯化、菌株鉴定及致病性测定,并研究了病原菌的生物学特性。在此基础上,进行了病原菌有效杀菌剂的室内筛选。结果表明,引起柳叶白前白绢病的病原菌(BQ-1)为罗耳阿太菌Athelia rolfsii,属担子菌门,半知菌亚门,其无性态为齐整小核菌Sclerotium rolfsii。病原菌菌株BQ-1的最佳生长温度为2530℃,最适生长p H为58,光暗交替更适合病原菌的生长。杀菌剂筛选结果发现化学杀菌剂石硫合剂、氟硅唑和植物源杀菌剂蛇床子素对BQ-1具有良好的抑制效果。菌株BQ-1与花生白绢病菌株HS-1具有极高的同源性,两者18S r DNA与TEF序列拼接结果相似度高达99.09%,推测柳叶白前白绢病的暴发可能由花生白绢病传染导致。柳叶白前生产上应避免同花生轮作和邻作,并在6—10月高温多雨季节清沟排水、降低田间湿度和合理施用农药。

During the high-temperature and rainy season from June to October in 2017—2019,serious southern blight broke out in the Cynanchum stauntonii planting area in Tuanfeng county,Hubei province,which had a great impact on the yield and quality of medicinal materials.In this study,the pathogen of C.stauntonii was isolated,purified,and identified,and the pathogenicity was tested according to Koch’s postulates.Meanwhile,the biological characteristics of the pathogen were analyzed.On this basis,the effective fungicides were screened in laboratory.Finally,the pathogen(BQ-1)was identified as Athelia rolfsii(Deuteromycotina,Basidiomycota,anamorph:Sclerotium rolfsii).The optimum growth conditions for BQ-1 were 25-30℃,p H 5-8,and alternating light and dark.The effective chemical fungicides were lime-sulphur-synthelic-solution(LSSS)and flusilazole,and the effective botanical fungicide was osthole.BQ-1 was highly homologous to the pathogen HS-1 of peanut southern blight,with the similarity of 18S rDNA and TEF sequences at 99.09%.The southern blight in C.stauntonii might be resulted from that in peanut.In the production of C.stauntonii,the following measures should be taken:avoiding rotation or neighboring with peanut,draining water from June to October to reduce humidity,and reasonably applying fungicides.