[Objective] The aim was to know the pathogenic fungi types and distribution law in ginseng rhizosphere soil.[Method] During May to Oct.in 2008 and 2009,more than 200 soil samples were collected from ginseng rhizosphere soil in Ji an City,Fusong County of Jilin Province and Huanren County of Liaoning Province.Soil dilution plate method and soil particle method were adopted to isolate and culture soil fungi,then classification and identification were carried out.[Result] 33 species of 22 fungal genera were id...
[Objective] The research aimed to study the optimum liquid fermentation condition of Trichoderma hamatum Th12 strain,which provided the theory basis for studying and developing the biological control agent of Trichoderma spp.[Method] By using the diluted soil plate method and the plate confrontation method,Trichoderma hamatum Th12 strain was identified.Moreover,the influences of carbon source,nitrogen source,fermentation time,fermentation temperature,initial pH,inoculation amount,bottling capacity and shaker speed on the mycelium yield of Trichoderma hamatum Th12 were studied.[Result] The optimum liquid fermentation conditions of Trichoderma hamatum Th12 strain were:glucose as the carbon source,peptone as the nitrogen source,fermentation temperature was 25 ℃,initial pH was 6,inoculation amount was 0.8 ml,bottling capacity was 50 ml,shaker speed was 180 r/min.Trichoderma hamatum Th12 strain was cultivated 3 d under the condition,and the mycelium yield was the highest.[Conclusion] Under the optimum liquid cultivation condition,Trichoderma hamatum Th12 strain could provide the mycelium amount which was used for preventing and controlling Fusarium oxysporum and Rhizoctonia solani of lawn to the utmost extent.