外源人参三萜皂苷对新林土中土壤微生物群落的影响

人参皂苷不仅是人参主要的药用活性物质,而且人参皂苷是人参化感作用的主要化感物质,其在人参植株生长及生态适应性方面发挥重要作用。为了研究人参皂苷对土壤微生物群落的影响,采用外源添加的方式研究人参总皂苷对新林土中微生物群落动态的影响,分析新林土中微生物群落代谢活性的变化趋势,探讨人参皂苷对土壤微生物群落的生态学效应。与对照相比,加入人参总皂苷10 d和40 d后新林土中土壤微生物群落的代谢活性均显著高于对照组,处理10 d后土壤微生物群落多样性指数除了均匀度指数(E)外,其他多样性指数随皂苷浓度升高呈现出先升高后降低的趋势,其中,低浓度处理碳源利用丰富度指数(S)与对照相比差异显著。后期除了均匀度指数(E)外,其他多样性指数高于对照。人参总皂苷可改变新林土中土壤微生物群落的组成和代谢活性,人参皂苷在土壤中的积累可以改变土壤微生态环境从而影响人参生长。

Influence of exogenous ginsenosides on new forest soil microbial communities

Ginsenosides are the main active ingredient and allelochemicals of Panax ginseng, and they play an important role in ginseng growth and in ecological adaptation. To study the influence of ginsenosides on soil microbial communities, the method of given exogenous total ginsenosides of different concentrations were used to study the influence of ginsenosides on new forest soil microbial community, evaluate the change of metabolic activity of microbial community and investigate the ecological effect of ginsenosides on soil microbial community. Results showed that, exogenous total ginsenosides promoted metabolic activity of microbial community in new forest soil at different concentrations compared with the control after 10 d and 40 d treatment. After 10 d,except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest firstly increased then decreased with increase of the total ginsenosides concentration. The Substrate richness for 0.01 g·L^-1 soil treatment was significantly different from that of the control. After 20 d, 30 d and 40 d, except for the Evenness index, all of the other indices indicated that the functional diversity of the soil microbial community in the new forest increased with total ginsenosides. These results suggested that ginsenosids can change soil microbial community and microbial metabolic activity, which alter soil microbial ecology and accordingly affect the growth of ginseng with accumulation of ginsenosides in the soil.