大白菜菌核病病原菌鉴定及其主要生物学特性

Identification and Main Biological Characteristics of Sclerotinia Rot Pathogen in Chinese Cabbage

为明确大白菜菌核病病原菌的种类及其主要生物学特性,以大白菜菌核病病株上分离获得的菌株XN001为试验材料,对菌株进行致病性检测和形态学观察,并结合病原菌ITS区序列分析鉴定病原菌的种类,此外,通过改变病原菌菌丝和菌核的培养条件,研究病原菌的主要生物学特性。结果表明:大白菜菌核病病原菌与油菜菌核病相同都是核盘菌;菌株XN001在p H值4~11菌丝均可生长,p H值4时生长最快;菌丝生长最适温度为20~25℃;诱导菌核萌发的最适温度为4~10℃,菌核在4℃下处理3~5周,萌发效果最好;菌核经低温诱导后,培养温度在15~25℃,最适宜菌核萌发。可见,大白菜菌核病病原菌为核盘菌,适宜在酸性常温条件下生长,菌核的萌发需要低温诱导。

In order to clarify the pathogen type of Chinese cabbage Sclerotinia rot and further study its main bi-ological characteristics,A strain XN001 of Chinese cabbage Sclerotinia rot was isolated from Chinese cabbage plant infected by pathogen and identified its type through pathogenicity test,morphology observation and analysis of nucle-otide sequence of internal transcribed spacer (ITS).In addition,the main biological characteristics of pathogen were also studied by changing culturing conditions of mycelial and sclerotia.The results showed that:The pathogen of Chinese cabbage Sclerotinia rot was as same as Sclerotinia rot of colza and both of them were Sclerotinia sclerotio-rum.It was suitable for strain XN001 growing when the pH value was between 4 to 11,the favourable pH value for mycelium growth was 4;The optimal temperature for its mycelium growth was between 20 ℃ and 25 ℃;The optimal temperature for inducing sclerotia germination was between 4 ℃ and 10 ℃,and the sclerotia germination was best when treated for between 3 and 5 weeks under 4 ℃;It was suitable for sclerotia germination when the culturing tem-perature was between 15 ℃ and 25 ℃ after low temperature treated.Obviously,the pathogen of Chinese cabbage Sclerotinia rot was S.sclerotiorum,it was suitable for growth at the conditions of acid and ambient temperature and the germination of sclerotia need low temperature induction.