利用松材线虫的内寄生真菌Esteya vermicola防治松萎蔫病

Application of Esteya vermicola,an endoparasitic fungus of the pinewood nematode,for controlling pine wilt disease

Esteya vermicola是首次发现的松材线虫的内寄生真菌。最近从韩国土壤中发现了该菌的一个新菌株。该菌株能产生两种孢子,并能在4~5d内感染几乎所有测试的松材线虫分离物。最近2年里在韩国进行了该菌株的温室和林间的接种试验,使用了3种方法进行接种,即喷施、注干和将感染的松材线虫接种到松树上。结果证明,该菌在松树幼树中生长并侵染到接种松树中的松材线虫,在松树中也观察到该菌的存在。目前,对该菌的使用方法和施用配方的评价和商品化工作正在展开。

Esteya vermicola,the first endoparasitic fungus is founded to be associated with the pinewood nematode（PWN）,shows great potential as a biological control agent for combating the devastating pine wilt disease.Recently,new E.vermicola strains have been isolated from soil in Korea.These straits have two different types of conidiogenous cells and conidia.However,only the lunate conidia are adhesive and can attach to the cuticle of the PWN and cause subsequent infection.In vitro,E.vermicola kills and colonizes almost all the tested pinewood nematode isolates within 4—5 days and is highly infective.However,to determine its potencial as a biocontrol agent for the PWN studies are needed on the feasibility of using the fungus.Isolation results and the taxonomic status of E.vermicola suggest that it is associated with vector beetles and affected trees.Consequently,greenhouse tests were done using the fungus to control the PWN and during the last 2 years field tests have been done in mountainous areas.Three application methods were used in the experiments：suspension spraying,trunk injection into trees,and applying infected nematodes onto trees.The results showed that E.vermicola grew into pine seedlings and successfully infected PWNs and E.vermicola mycelium were observed within pine trees.Presently,studies are being made to evaluate the application and formulation of E.vermicola as a commercial biocontrol agent.