入侵植物薇甘菊的根际土壤微生物特征

Soil microbial characteristics in the rhizosphere of exotic invasive Mikania micrantha

盆栽试验比较入侵植物薇甘菊(Mikania micrantha)和本土植物爬山虎(Parthenocissus tricuspidata)生长过程中的根际土壤微生物结构(磷脂脂肪酸方法)、酶活性及理化性质的特征,以期揭示薇甘菊入侵过程中的土壤微生物学机制。结果显示:与本地种爬山虎相比,薇甘菊根际土壤p H值降低,有机质、总氮、铵氮和有效磷含量减少,但硝态氮含量增加。薇甘菊根际土壤的细菌、真菌、放线菌脂肪酸含量高于爬山虎,脱氢酶、脲酶、蛋白酶和磷酸酶活性显著增强。相关分析表明土壤微生物磷脂脂肪酸含量及酶活性与土壤有机质、氮、磷营养盐呈显著相关。

Exotic Mikania micrantha and native Parthenocissus tricuspidata were planted in pots to study the effects on the physico-chemical characteristics, microbial community structure （expressed by phospholipid fatty acids, PLFAs） and enzymatic activities in the rhizosphere soil. The results indicated that soils in the rhizoshpere of M. micrantha had significantly lower levels of physico-chemical properties, including pH value, organic matter, total N, ammonium N, and available P, but higher contents of nitrate N were found in M. micrantha rhizosphere soil. M. micrantha increased significantly the activities of dehydrogenase, protease, phosphatase and urease. The diagnostic PLFAs of bacteria, fungi, actinomycetes and fungi to bacteria ratio had similar trends with that of protease. The canonical correlation analysis revealed that differences in diagnostic PLFAs and enzymatic activities were significantly correlated to the differences in physico-chemical variables, especially with the content of carbon, N and available P.