不同植物对黄顶菊根际土壤微生物和土壤养分的影响

目的] 不同植物对外来入侵植物的抵御能力不同，研究不同植物对入侵植物根际土壤生态的影响可为筛选入侵植物的竞争替代植物提供科学依据。方法] 利用同质园试验，以入侵植物黄顶菊为研究对象，设置黄顶菊单种、黄顶菊与不同植物（地肤、苘麻、苏丹草、反枝苋）混种处理，采用磷脂脂肪酸分析方法来研究不同植物对黄顶菊根际土壤微生物群落结构的影响，并结合土壤养分的变化探究不同植物对黄顶菊根际土壤生态的影响。结果] 与黄顶菊单种相比，地肤和苘麻降低了黄顶菊根际微生物的总含量，改变了黄顶菊根际微生物群落结构。地肤、苘麻能竞争性抑制黄顶菊对铵态氮的吸收，从而抑制黄顶菊的生长。结论] 不同植物的抵御能力与其土壤生态有关，替代植物通过改变黄顶菊根际土壤微生物，抑制黄顶菊对氮的吸收，从而抑制黄顶菊的生长，实现对黄顶菊的替代控制。

Effects of different plants on soil microbial communities and nutrients in the rhizosphere soil of Flaveria bidentis

Aim] Different plants have different resistance abilities to exotic species. Studying the influence mechanism of different species on the rhizosphere soil ecology of invasive species may provide a scientific basis for choosing the replacement plants.Method] The homogenous garden experiment was used to study the ability of the four plants (Kochia scoparia (Linn.) Schrad, Abutilon theophrasti Medicus, Sorghum sudanense (Piper) Stapf and Amaranthus retroflexus L.) to resist the invasion of F. bidentis. There were five treatments in the experiment:the monoculture of F. bidentis and the mixture treatments that F. bidentis mixed with each of the four plants. The phospholipid fatty acid analysis method was used to study the effects of different plants on the microbial community structure and soil nutrient in the rhizosphere soil of F. bidentis to explored their mechanism on the rhizosphere soil ecology of F. bidentis.Result] K. scoparia and A. theophrasti reduced the total microbial biomass and changed the microbial community structure of F. bidentis comparing to those in the monoculture treatment of F. bidentis. K. scoparia and A. theophrasti could competitively inhibit the absorption of ammonium nitrogen and then the growth of F. bidentis.Conclusion] The resilience of different plants was related to the soil ecology. Replacement plants could inhibit growth of F. bidentis by changing the soil microbes in the rhizosphere soil and inhibiting nitrogen uptake of F. bidentis, which achieved the control of the growth and spread of F. bidentis.