食线虫真菌蠕虫埃斯特菌对植物寄生线虫的侵染特性

Infection characteristics of nematophagous fungus Esteya vermicola to plant parasitic nematodes

为评价食线虫真菌蠕虫埃斯特菌Esteya vermicola菌株NKF 13222的生防应用价值,采用2%水琼脂培养基平板接种法测定了该菌株对7种植物寄生线虫的诱引、黏附和侵染能力,并比较了其对不同线虫的侵染特性。结果显示,该菌株的菌丝对松材线虫、拟松材线虫、腐烂茎线虫和水稻干尖线虫均有诱引作用,而对南方根结线虫、禾谷孢囊线虫和穿刺短体线虫无诱引作用;菌株的粘性分生孢子对有诱引现象的4种线虫都能黏附,接种24 h后的黏附率达到82%~99%,对无诱引现象的3种线虫不能黏附;粘性分生孢子黏附虫体后对不同线虫的侵染力存在差异,接种7 d后的松材线虫死亡率可达98%,而拟松材线虫、腐烂茎线虫和水稻干尖线虫死亡率分别为43%、35%和9%。表明蠕虫埃斯特菌不仅是松材线虫的强内寄生真菌,而且对其它重要植物寄生线虫也具有一定的应用潜力。

In order to explore the biocontrol potency of the nematophagous fungus Esteya vermicola strain NKF 13222,the characteristics of attraction,attachment and infection towards seven plant parasitic nematodes were evaluated by inoculating nematodes on 2% water agar plates with fungus. The results showed that the mycelia of strain NKF 13222 attracted the juveniles of Bursaphelenchus xylophilus,B. mucronatus,Ditylenchus destructor and Aphelenchoides besseyi instead of Meloidogyne incognita,Heterodera avenae and Pratylenchus penetrans. Lunate conidia of strain NKF 13222 were found to be attached on the bodies of four attracted nematode species 24 hours after inoculation,and their rate of attachment ranged between 82%- 99%,while no attachments were observed in case of non-attracted nematode species. The infection ability of lunate conidia varied significantly among different nematode species. The infection rates of spores for B. xylophilus,B. mucronatus,D. destructor and A. besseyi were98%,43%,35% and 9% at seventh day after inoculation,respectively. The study proved thatE. vermicola strain NKF 13222 not only had a high infectivity against B. xylophilus,but could act as an alternative biocontrol agent for some other plant parasitic nematodes.