核盘菌菌核重寄生菌的分离筛选

从云南、四川、甘肃、陕西、山西、湖南、河北、北京、黑龙江、吉林、辽宁、内蒙古等12个省市(区)采集土样103份,采用室内菌核诱捕的方法分离得到了148个真菌菌株,分别属于12个属。其中黏帚霉属(Gliocladium spp.)77个菌株,包括4个种,占全部分离菌的52.03%,为优势种群;其次为青霉菌(Penicillium spp.)21个菌株,分离率为14.19%;镰刀菌(Fusarium spp.)16个菌株,占10.81%;木霉菌(Trichoderma spp.)13个菌株,占8.78%;轮枝菌(Verticillium spp.)8个,占5.41%。对其中寄生率较高的菌株进行回接,结果表明,黏帚霉和木霉寄生核盘菌(Sclerotiniasclerotiorum)菌核的能力强,接种1周后导致菌核腐烂,但不同菌株之间存在差异;而镰刀菌、轮枝菌对菌核的寄生能力较差。并且,首次用菌核诱捕的方法从云南省玉溪市烟草田土壤中分离获得了一株能寄生菌核的捕食线虫丝孢菌,经鉴定为椭圆单顶孢[Monacrosporium ellipsosporum(Preuss)Cooke&Dickinson]。

Isolation and Screening of Mycoparasited on Sclerotinia sclerotiorum

In the current research work,103 soil samples were collected from 12 provinces(cities) including Yunnan,Sichuan,Gansu,Shaanxi,Shanxi,Hunan,Hebei,Beijing,Heilongjiang,Jilin,Liaoning,Inner Mongolia.The cultured sclerotia were used as the host to trap mycoparasitic fungi from the soil samples.The experiment resulted in 148 isolates of mycoparasitic fungi belonging to 12 genera.Among the isolates,77 isolates were four Gliocladium species with 52.03% isolation ratio,the dominant population of mycoparasitic fungi.The other isolated fungi were 21 isolates of Penicillium spp.with 14.19% isolation ratio,16 isolates of Fusarium spp.with 10.81% isolation ratio,13 isolates of Trichoderma spp.with 8.78% isolation ratio,8 isolates of Verticillium spp.with 5.41% isolation ratio.The inoculation of the high isolation ratio indicated that the isolates of Glicocladium and Trichoderma exhibited greater capabilities to parasitize sclerotia.It was found that the sclerotia began decomposed or rotted after one week of inoculation.The various isolates showed difference in mycoparasitism of sclerotia,while the isolates of Penicillium and Verticillium exhibited poor parasitic characteristics.One nematode-trapping hyphomycetes was isolated from tobacco soil in Yuxi city of Yunnan province,it was identified as Monacrosporium ellipsosporum(Preuss) Cooke & Dickinson.The fungus was found to frequently colonize the sclerotia of Sclerotinia sclerotiorum in field.