Isolation Of Parasitic Fungi Of Sweet Potato Rot Nematode

Potato rot nematode(Ditlylenchus destructor) is badly endangering many crops. This nematode is one of the danger disease on sweet potato. Its population is direct correlation with crop losing. We mostly control this nematode by nematocide, but the indecomposable ingredient of nematocide is harm to environment. The nematode biological control is gradually regarded, so, looking for the parasitic fungi of potato rot nematode is a important way of nematode biological control.Basing upon Young, Seung and linmaosong`s method, I improved the culture potato rot nematode. in laboratory condition, the nematode was cultured for 43d on colony of Fusarium solani at 20oC under darkness, leading to 23777 nematodes reproduced per cover of Petri dish (dia. 9cm), at 25℃ leading to 46000—70000 reproduced. Comparing with Young Ho Kim＆ Seung Hwan Ohh's method, this method is not only more efficient but also more simple, and the nematodes gained is more clean because they moved into the inside of the Petri dishes cover and congregated together there. I collected 78 soil sample from Liaoning province, Hebei province etc in diseased field of sweet potato. By direct isolating and indirect isolating to isolate the parasitic fungi of potato rot nematode. 40 parasitic fungus was isolated. After primary identifying:3 Alternaria,1 Coremium ,1 Stachybotrys,1 Rhizopus,1 Aspergilleae,1 Botryosporium,1 Gongromeria,2 Penicillum or Penicillum Solms-Laubach。There were much Catenaria sp(FIG.3-1) in No.56 and NO.57.This is the first be observed in China by now. On the limited technology conditions, I did not obtain this parasitic fungi on PDA. The remnant parasitic fungus most have not spore in at the present time, go on identifying next. All fungus is cultured on CMA, NO.63-1, 41-1,57-2,76-2,73-1,75-3-2 do not produce in CMA. Portion of parasitic fungus was described, more work is necessary. All isolated fungus were determined the parasitic rate. The result turn out: NO. 15-1,22-10,26-1,27-8,27-5,42-2,43-2,50-1,57-3,61-3,64-3,70-2,75-1,75-2,75-3-2,76-1,77-1 can restrain the reproduce of potato rot nematode. The parasitic rate is respective: 77%,31%,60%,55%,68%,76%, 85%,92%, 51%,60%,54%, 58%,56%,46%,88%,71%,51% .NO. 50-1,75-3-2,42-2 can restrain the nematode best, The parasitic rate is respective: 92％,88％,85％.The remnant fungus can not restrain the population of potato rot nematode. We hope to more filtrate and look for the best restrain the population of potato rot nematode . It will work in control of potato rot nematode.