Soil Microbial Population Change And Identicification Of Trichoderma Spp.in Liaoning Oak Yards

The abundant eucalyptus resources in Liaoning Province provided sufficient feed resources for tussah,but the unreasonable and excessive use of eucalyptus resources in the tussah rearing process caused a certain impact on the ecological environment of the Oak yards.So the scientific and rational construction and utilization of the Oak yards are the concerning topics.The ecological environment of Oak yards was reflected from the vegetation coverage of the Oak Trees,the rearing amounts of Tussah,the soil fertility and the soil microbial population abundance.However,there is still a lack of research on the microbial population changes in the Oak yards.Therefore,soils were selected from oak yards with good ecological construction and adjacent forest to analyze the changes of microbial populations in the soil,which maybe a soil microbial indicators for the ecological construction of the Oak yards for providing a basis on the ecological construction and the rational use of the Oak yards.Trichoderma is a kind of fungus widely distributed in the soil.It is also distributed in the roots of the Oak Trees.The species and distribution of Trichoderma spp.in different areas of Liaoning Province were studied to explore the species and diversity of Trichoderma in the Oak yards of different regions,and provide reference data for obtaining biocontrol of excellent Trichoderma and Eucalyptus diseases adapted to habitat conditions in different regions.The physical and chemical properties of the soil in the Oak yards and adjacent forests showed that there was a significant difference in water content,p H value and available potassium content between the Oak yard and the forest soil(p<0.05),while the organic matter content,available phosphorus content and available nitrogen content were not difference.Illumina Mi Seq high-throughput sequencing method was used to analyze the microbial diversity of the soils in the Oak yards and forests.The total OTU number of the bacteria was higher than that of the fungi.The number of fungal OUT is significantly different between the two places..? diversity analysis of bacterial and fungal communities showed that there was no significant difference in soil microbial diversity and abundance between the two soils.;there were differences in the species and composition of microorganisms;Beta diversity analysis indicated that the similarity of the bacterial community structure between the Oak yard and the adjacent forest land was low,and the difference was large.As far as the fungal community was concerned,there was no obvious separation between the two groups of the Oak yard and the forest.The similarity of the community composition was higher,the difference between the groups was not obvious,and the intra-group difference of the Oak yard is higher than that of the forest.Spearman correlation network analysis of dominant species interactions showed that most soil bacteria are cooperative,involved in soil material exchange and energyconversion,and the fungi in soil are cooperative,especially Trichoderma,and many genus is a cooperative relationship.Through the isolation and identification of Trichoderma spp.in the roots of eucalyptus in nine counties of Liaoning Province,a total of 265 strains of Trichoderma were obtained.A total of 12 Trichoderma strains were identified by combination of morphological and molecular biological identification methods,The shape,color,presence or absence of the spore-forming area of ? ? the Trichoderma spp and the branching pattern of the conidiophores were described.The isolation rates of Trichoderma in different regions are significantly different.It shows that the ecological construction of Zhuanghe City?Fengcheng City?Benxi County and Dongling District has a large diversity index,and the diversity of Trichoderma is rich.The results of confrontation culture of Trichoderma and Fusarium showed that different Trichoderma had different effects on Fusarium.For example,TFC 2-1-6 could cover Fusarium,but TFC 2-2-1 could not cover Fusarium.There was a significant difference in the inhibition rate of Trichoderma against Fusarium.TSY 2-2-2(T.hamatum)had the best inhibition,and the inhibition rate was 70.54%,followed by TFS 2-2-3(T.koningiopsis),TSY2-1-4(T.vriens)and the inhibition rate were 64.42% and 63.25%,respectively.The same Trichoderma lived in different regions,and the inhibition effect was also different.There were many strains with high inhibition rate on Fusarium in Shenyang and Fengcheng,and more strains with low inhibition rate on Fusarium from Xiuyan.