加拿大一枝黄花对土壤微生物区系的影响研究

以外来入侵杂草加拿大一枝黄花和土著种一枝黄花为研究材料，检测了这两种植物的根部土壤中微生物区系和微生物生理类群的变化。结果表明，具化感作用潜力的加拿大一枝黄花明显影响了土壤中根部微生物群落多样性。具体表现在加拿大一枝黄花根部土壤中的真菌数量低于对照土，而细菌和放线菌的数量则有增多。土著种一枝黄花对根部土壤中微生物的生长均为抑制效应。进一步分析显示，加拿大一枝黄花的根系分泌物对土壤的亚硝酸细菌、好气性自生固氮菌、硫化细菌、氨化细菌和好气性纤维素分解菌的数量具有促进作用，而对反硝化细菌、嫌气性纤维素分解菌和反硫化细菌的生长有抑制效应。据此，文中还探讨了影响外来入侵植物扩散力的生态机制。

Impacts of Invasive Alien Weed Solidago canadensis L. on Microbial Population in the Root Soil

studies were conducted on microbial flora in the root soil of invasive alien weed Solidago canadensis L. and Solidago decurrens Lour. The results indicated that allelopathic weed Solidago canadensis L. had a significant influence on the microbial flora. Solidago canadensis L. caused greater reduction on the number of fungi compared with the blank. The reverse was true on bacteria and actinomycetes. While native weed Solidago decurrens Lour. inhibited the growth of fungi, bacteria and actinomycetes. Further analysis indicated that the root exudates of Solidago canadensis L. promoted the number of nitrite bacteria, aerobic azotobacter, sulphate reducer, ammonifier and aerobic cellulose-decomposer. But the growth of denitrifier, anaerobic cellulose-decomposer and desulphate reducer were inhibited by the invasive alien weed. Finally, the ecologic mechanisms that may influence the diffuse of invasive alien plant were also discussed.