Study On Microbial Community Structure In Ginseng Soil

In the course of ginseng development, there were many plagued issues. Cultivate ginseng in farmland was low-yield and heavy disease. Wild ginseng soil under forest was low seeding survival and few physical characteristics of pure wild mountain ginseng. There were erythroderma, contionuous cropping obstacle and other issues.The main facter of above-mentioned problems was changes of soil environment.Its microorganisms could be sensitive to its changes, respond to changes of soil ecological mechanisms and environmental stress, and lead to changes in community structure.So soil microbial community was considered an early warning and sensitive indicators of soil ecosystem changes.It could instruct soil quality changes and determine soil ecosystem. There were many studies on the impact of physical and chemical properties by ginseng cultivation, few studies on soil microbial characteristics, and blank on soil microbial metabolic function, genetic and community structure diversity. In this paper, we used phospholipid fatty acid analysis to investigate the microbial community structural characteristics of ginseng root zone soil, including two pure wild mountain ginseng soil, different cropping year's conversion of forest to cultivate ginseng soil, cultivate ginseng soil in farmland and wild ginseng soil under forest. In order to reveal the impact of soil microbie by ginseng growth in different circumstances, and provide supported theories for ginseng industry. Experimental data was analysed with the correlation analysis, variance analysis and principal component analysis.Main original conclusions were shown as follows.1.Different cropping year's wild mountain ginseng soil had the different microbial community structural characteristics. No.1(about 12-year-old )and its contrast soil's microbial community structures were greatly different from No.2(about 25-year-old) and its contrast soil's. No.2 soil's microbial community structure was better than its contrast soil's,but No.1 soil's was worse than its contrast soil's.Compared with theirs contrasts ,the contents of fungi/bacteria were higher in No.1 soil and lower in No.2 soil ,or the contents of G+/G- were higher in No.2 soil and similar with No.1 soil.The main differences of microbial community structures were the differences of the biomass of total microbe and fungi.2.Different cropping year's conversion of forest to cultivate ginseng soil had the different microbial community structural characteristics.2-year-old to 4-year-old soil's microbial community structures were gradually decreased and 2-year-old soil's was greatly better than 3-year-old and 4-year-old soil's. The content of fungi/bacteria was higher in 3-year-old and 4-year-old soil, or the content of G+/G- was higher in 3-year-old soil.The main differences of microbial community structures were the difference of the total microbial biomass .3. Different cropping year's cultivate ginseng soil in farmland had the different microbial community structural characteristics. 1-year-old to 4-year-old soil's microbial community structures had a gradually "V"-shaped change and the lest point was 2-year-old soil's. There were not greatly changes among different cropping year's soil. The content of fungi/bacteria were higher in 2-year-old soil,or the content of G+/G- were higher in 1-year-old and 4-year-old soil.The main differences of microbial community structures were the differences of the biomass of total microbe and fungi.4. Different cropping year's wild ginseng soil under forest had the different microbial community structural characteristics.2-year-old,3-year-old,4-year-old,5-year-old,10-year-old and 15-year-old soil's microbial community structures had a gradually "И"-shaped change and the turning point was 4-year-old and 10-year-old soil's. 2-year-old,3-year-old,4-year-old,10-year-old soil's microbial community structures were greatly different form 5-year-old and 15-year-old soil's. The content of fungi/bacteria were higher in 5-year-old and 15-year-old soil,or the content of G+/G- were higher in 2-year-old,3-year-old,4-year-old and 15-year-old soil.The main differences of microbial community structures were the differences of the biomass of total microbe and fungi.5. Different type but the same cropping year's ginseng soil had the different microbial community structural characteristics.4-year-old wild ginseng soil under forest's microbial community structure was greatly better than 4-year-old conversion of forest to cultivate ginseng soil's and 4-year-old cultivate ginseng soil in farmland's.But 4-year-old conversion of forest to cultivate ginseng soil's microbial community structure was the same with 4-year-old cultivate ginseng soil in farmland's.No.1 wild mountain ginseng soil's was the same with 10-year-old wild ginseng soil under forest's.The ginseng soil's main structure all was fungi .The contents of fungi/bacteria and G+/G- were higher in 4-year-old conversion of forest to cultivate ginseng soil and 10-year-old wild ginseng soil under forest's content of G+/G- was higher than No.1 wild mountain ginseng soil's.The main differences of microbial community structure were the differences of the biomass of total microbe and fungi.