Study On The Soil Fungi In The Nature Reserves Of Jiuzhaigou County

25 soil samples were collected from the three nature reserves of Jiuzhaigou County. Quantities of fungi were determined with the dilution plate technique. The isolated fungi were identified based on their morphological characters and molecular phylogenetic data of ribosomal internal transcribed spacer (ITS) sequences. According to the quantities, communities and their distribution in this three nature reserves, the fungi diversity in these areas was analyzed. And the Trichoderma spp. strains were selected to conduct their biocontrol potentials.The average quantity of the surface soil fungi in these 25 sample points was 6.427×103±7.675×103 cfu·g-1dry soil. There were some differences in the total quantity of fungi between the three nature reserves, the results showed that Jiuzhaigou Nature Reserve (1.09×104cfu·g-1dry soil)>Wujiao Nature Reserve (5.422×103 cfu·g-1dry soil)>Baihe Nature Reserve (3.051×103 cfu·g-1dry soil).111 fungi strains were combined and they were identified with two methods. The results showed that 39 genera which include Aureobasidium spp., Emericella spp., Bionectria spp., Myrothecium spp.etc were identified and 4 genera could not be identified which were doubted for new genera. Analyzed the ribosomal internal transcribed spacer(ITS) sequences of different strains of Penicillium spp.. The results showed that Penicillium spp. had 13 different types for rDNA-ITS sequences. The same analysis had made among Aspergillus spp.and Humicola spp., and the result showed that Aspergillus spp. had 4 different types for rDNA-ITS sequences, and Humicola spp. had two.The main groups were Penicillium spp., Aspergillus spp., Trichoderma spp.and Humicola spp.in three nature reserves. Penicillium was the comparative predominance genera, and its quantity percentage of Jiuzhaigou, Baihe and Wujiao were 21.01%,31.44% and 20.65%, respectively. The abundance(S), Shannon-wiener's diversity(H'), Pielou's evenness(E) and dominance index(D) of fungi were all followed a normal distribution, and their average were 12.0400±3.3600,1.9382±0.3580,0.7496±0.1623 and 0.2110±0.1050, respectively.The determination of growth rate of Trichoderma spp. strains showed that most of them grew rapidly. The biocontrol capability of 5 Trichoderma strains which grew rapidly were tested, and the results showed that T8 had the best broad-spectrum antimicrobial activity. The result of confront culture showed that inhibition rates of T8 against Fusarium oxysporum, Fusarium graminearum and Colletotrichum gloeosporioires were 60.22%, 58.33% and 54.90%, respectively. And the result of inhibition rates of sterile fermented fluid also showed that T8 showed highest inhibition rates. T8 was identified as Trichoderma harzianum.