3种寄生真菌发酵液对大豆胞囊线虫4号生理小种毒力研究

The virulence of 3 parasitic fungi fermentation filtrates on race 4 of soybean cyst nematode

镰孢菌(Fusarium spp.)、厚垣轮枝菌(Verticillium chlamydosporium)和淡紫拟青霉菌(Paecilomyces lilacinus)在连作大豆田中普遍存在。本研究从大豆田土壤中分离了这3个属的真菌,实验室条件下探讨了3个属12个菌株的发酵液对大豆胞囊线虫4号生理小种胞囊、卵孵化抑制作用和对大豆胞囊线虫2龄幼虫的致死作用。结果显示,3个属12个菌株的发酵液对大豆胞囊线虫4号小种都具有抑制作用,抑制其胞囊和卵孵化,并对二龄幼虫具有致死作用。12个菌株发酵原液对胞囊孵化抑制率在50.6%~85.6%,对卵孵化抑制率在51.3%~69.7%,稀释5倍、10倍、20倍和50倍发酵液也对胞囊孵化和卵孵化也具有抑制作用。12个菌株发酵液对大豆胞囊线虫2龄幼虫均具有致死作用,原液在处理1h就开始出现致死毒性,48 h到72 h致死作用达到高峰。供试菌株中以镰孢菌的F-9菌株、淡紫拟青霉菌的P-E菌株和厚垣轮枝菌V-25菌株发酵液对大豆胞囊线虫抑制作用显著。该结果可为开发大豆胞囊线虫生防菌提供依据。

Fusarium spp.,Verticillium chlamydosporium and Paecilomyces lilacinus have been widely observed in continuous soybean field.In this study,we isolated 3 fungi from soybean field,and tested the inhibition of their fermentation filtrates on cyst and egg hatching to race 4 of soybean cyst nematodes(SCN)as well as mortality of the second instar larvae(J2)under laboratory conditions.The results showed that the fermentation filtrates of 12 strains from the 3 fungi had inhibitory effects on race 4 of SCN.The fermentation filtrates inhibited cyst and egg hatching of SCN,and had a lethal effect on J2.The inhibition rates of the fermentation filtrates from 12 strains on cyst hatching and egg hatching of SCN ranged from 50.6%-85.6%and 51.3%-69.7%respectively.The 5-fold,10-fold,20-fold and 50-fold diluents of the fermentation filtrates also showed an inhibitory effect on cyst and egg hatching of SCN.The fermentation filtrates from 12 strains had a lethal effect on J2 of SCN.The raw fermentation filtrates had lethal toxicity when J2 was treated 1 h later,and the lethal effect reached a peak from 48 to 72 h.Among the tested strains,the fermentation filtrates from F-9 strain of Fusarium,P-E strain of Paecilomyceslilacinus,and V-25 strain of Verticillium significantly inhibited soybean cyst nematodes.The results would provide information for the development of biocontrol bacteria against SCN.