不同浓度根系分泌物调控植物土壤微生物群落结构研究

土壤微生物群落分布受根系分泌物的影响较大，为研究其作用机理，采用根系分泌物溶液，对比分析不同浓度群落分布特点，同时对土壤酶活性及微生物量进行测定，并剖析其对微生物群落分布的作用，探究微生物商的反应机理。结果表明，不同浓度根系分泌物处理对土壤pH有较大影响，均显著低于对照组；土壤有机碳和全氮含量表现出一致规律，含量均高于对照组，而土壤全磷含量不受根系分泌物浓度的影响。不同浓度根系分泌物处理对土壤细菌、真菌、放线菌数量的影响也存在较大差异，根系分泌物浓度越高，细菌、真菌、放线菌数量和微生物总数越多，且均显著高于对照组。对于土壤微生物量碳、氮和磷，受根系分泌物浓度的影响显著，根系分泌物浓度越高，其含量也就越高，且均显著高于对照组。不同浓度根系分泌物处理对土壤微生物丰富度指数、Mcintosh指数的影响也存在较大差异，根系分泌物浓度越高，其微生物多样性指数也越高，且均显著高于对照组；而微生物优势度指数不受根系分泌物浓度的影响。综合来看，根系分泌物对单一碳源的利用能力存在显著差异，其群落分布特点差异显著。

Regulation of Plant Soil Microbial Community Structure by Different Concentrations of Root Exudates

In order to study the effects of plant root exudates on soil microbial community structure, and compare the distribution characteristics of communities with different concentrations, the soil enzyme activity and microbial biomass were measured, and the effects on the distribution of microbial communities were analyzed, and the microbial quotient were studied by adding plant root exudates to soil. The results showed that different concentrations of root exudates had significant effects on soil pH, which were significantly lower than CK; the content of soil organic carbon and total nitrogen which showed a consistent law were higher than CK, while the content of soil total phosphorus was not affected by the concentration of root exudates. The effects of different concentrations of root exudates on the number of soil bacteria, fungi and actinomycetes were also significantly different. The higher the concentration of root exudates, the more the number of bacteria, fungi, actinomycetes and microorganisms were, which were significantly higher than CK. The contents of carbon, nitrogen and phosphorus in microbial biomass were significantly affected by the concentration of root exudates. The higher the concentration of root exudates, the higher the contents, which were significantly higher than CK. The effects of different concentrations of root exudates on soil microbial richness index and Mcintosh index were also significantly different. The higher the concentration of root exudates, the higher the microbial diversity index, which were significantly higher than CK, while the microbial dominance index was not affected by the concentration of root exudates. On the whole, there were significant differences in the utilization ability of root exudates to a single carbon source, and the community distribution characteristics were significantly different.