Effects of exotic plant Ageratina adenophora invasion on mycorrhizal fungal community

The invasion of exotic plants and probability of successful invasion are affected by the interaction between exotic plants and soil microbes in invaded habitats. Furthermore, interactions among mycorrhizal fungi (MF) and exotic plants have been the focus of the response of soil microbial mechanisms to plant invasion. This study used nested PCR to detect MF in roots and rhizosphere soils of native weeds and A. adenophora in native weeds dominated community, A. adenophora and native weeds mixed community, and A. adenophora dominated community in A. adenophora invaded habitats. The results showed that MF community structures were different for different invasion phases. Glomus intraradices clones were detected in roots of native weeds grown in native weeds dominated community. G. intraradices clones were also noted in roots of A. adenophora grown in A. adenophora and native weeds mixed community. Only one Glomus (Glomus sp 2) clone was found in the roots of native weeds grown in A. adenophora and native weeds mixed community. No MF was detected in the roots of A. adenophora grown in A. adenophora dominated communities. Also two Glomus (Glomus sp 1 and Glomus sp 2) clones were obtained in the rhizosphere soils of A. adenophora dominated community. Trichoglossum hirsutum, Tricholoma saponaceum, Xylobolus subpileatus and Sarcodon imbricatus were detected in rhizosphere soils of A. adenophora grown in A. adenophora and native weeds mixed community. Camarophyllopsis hymenocephala, Lepista irina, T. saponaceum and Panellus serotinus were found in rhizosphere soils of native weeds grown in A. adenophora and native weeds mixed community. T. saponaceum was found in rhizosphere soils of native weeds grown in native weeds dominated communities. MF communities were changed by A. adenophora invasion and ectomycorrhizal fungi (EMF) more likely habited native weeds rhizosphere soils than A. adenophora rhizosphere soils. Arbuscular mycorrhizal fungi (AMF) accumulated more in rhizosphere soils of exotic A. adenophora than in native weeds rhizosphere soils. The probability of invasion changed MF community response to A. adenophora invasion, which suggested that A. adenophora heartened AMF in rhizosphere soils and induced positive AMF feedback, which enhanced A. adenophora invasiveness. The study highlighted one of the important soil microbial mechanisms of A. adenophora invasion in southeast China.