The Function Of AM Fungi On The Growth Competieion Between Eupatorium Adenoporum And Rumex Hastatus

Eupatorium adenophorum is one of the nine most seriously exotic invasive plants in China, which has caused huge effect on ecosystem and biodiversity.Arbuscular mycorrhizal (AM) fungi widely distribute in natural environment and can form symbiotic association with 80% terrestrial plants. Therefore, AM fungi can play an important role in the succession process of terrestrial ecosystem, invasion of exotic plants, and restoration and reconstruction of destructed ecosystem.The exotic invasive plant E. adenophorum and native plant Rumex hastatus of Yunnan Province were selected, and two AM fungi Glomus geosporum and Glomus etunicatum were used as inocula in Pot experiments in the greenhouse. The plant height, photosynthetic rate, biomass, N and P content and AM colonization rates were tested in this study. The function of AM fungi on the growth competition between E. adenophorum and R. hastatus were analysed. The main results are as follows:1. Survival rate of E. adenophorums seedlings increased with AM fungi inocula, and was significantly higher in the planted with R. hastatus than monoculture. However, AM fungi have no effect on the survival rate of R. hastatus.2. Seedling height of E. adenophorums conspicuously increased with AM fungi inocula, but no consistent results of R. hastatus inoculated with AM fungi during the cultivation period (1-3 months).3. In the two plant mixture culture, photosynthetic rates of E. adenophorums inoculated with two mixed AM fungi were higher than that inoculated with single AM fungus, and is significantly higher than that inoculated with Glomus etunicatum. AM fungi had not significantly effect on the photosynthetic rates of Rumex hastatus.4. AM fungi significantly increased shoot and root biomass of E. adenophorums regardless of monoculture and mixed culture, except for inoculation of Glomus geosporum in the mixed culture. In the monoculture, AM fungi increased shoot biomass of Rumex hastatus, and Glomus geosporum significantly increased its shoot biomass. In the mixed culture, the shoot and root biomass of Rumex hastatus significantly decreased when inoculated with Glomus etunicatum and two mixed AM fungi. AM fungi significantly decreased the root biomass of Rumex hastatus in both monoculture and mixed culture. 5. The colonization rates of AM fungi of E. adenophorums were more than 55% in all treatments, and were the highest when inoculated with Glomus geosporum, but there was no significant difference among the treatments. The colonization rates of AM fungi of Rumex hastatus were higher in the mixed inoculation than in the single inoculation of AM fungi.6. In the monoculture and mixed culture, AM fungi significantly decreased shoot-N content of E. adenophorums. AM fungi significantly decreased root-N content of E. adenophorums in the monoculture, but no significant difference in the mixed culture. AM fungi increased shoot-and root-N content of Rumex hastatus, except for in the inoculation of Glomus geosporum. AM fungi decreased shoot-and root-N content of Rumex hastatus, but no significant difference among the treatments.7. In the monoculture, AM fungi increased shoot- and root-P content of Eupatorium adenophorums, except for in the inoculation of Glomus etunicatum. In the mixed culture, AM fungi significantly increased shoot- and root-P content of Eupatorium adenophorums, except for in the inoculation of Glomus geosporum. In the monoculture, AM fungi increased shoot- and root-P content of Rumex hastatus, but Glomus etunicatum decreased its shoot-P content. In the mixed culture, AM fungi decreased shoot- and root-P content of Rumex hastatus, and the difference was significant in the inoculation of Glomus etunicatum.Our results indicate that AM fungi are beneficial to the exotic invasive plant Eupatorium adenophorums for the growth competition with native plant Rumex hastatus.