Pine wilt disease (PWD) is a deadly disease to pines (Pinus spp.) worldwide. The occurrence of PWD can reduce the relative abundance of root ectomycorrhizal fungi (
ECMF) and dark septate endophytes (DSE). However, the effects of exogenous
ECMF/DSE inoculation on the rhizosphere microbial community structure of Pinus tabulaeformis infected by pine wood nematode (PWN) is little known. Here, we tested how
ECMF/DSE may improve resistance to PWD by quantifying microbial
carbon biomass and soil enzymatic activity among different treatments at 6 and 9 months after PWN
infection. Denaturing gradient gel electrophoresis (DGGE) was used to study the microbial community structure at 3, 6, and 9 months after PWN
infection in the rhizosphere of P. tabulaeformis seedlings inoculated with
ECMF/DSE. The results showed that exogenous
ECMF/DSE inoculation reduced the disease severity caused by PWN
infection. After PWN
infection, the rhizosphere microbial
carbon of seedlings inoculated with Amanita vaginata, Suillus bovinus, Gaeumannomyces cylindrosporus, and Paraphoma chrysanthemicola was 38.16, 49.67, 42.11, and 96.05% higher than that of the control group, respectively. Inoculation of
ECMF/DSE inhibited the decrease of rhizosphere microbial biomass caused by PWN
infection. The richness and diversity of P. tabulaeformis rhizosphere fungi at 9 months were reduced by PWN
infection but partially recovered by the exogenous fungi (
ECMF/DSE) inoculation except for P. chrysanthemicola, which indicates a role of
ECMF/DSE in maintaining stability of the microbial community. Inoculation with
ECMF/DSE increased the beneficial bacterial (Thauera sp., Mesorhizobium sp., etc.) and fungal groups (Tomentella ellisii, Wilcoxina mikolae, etc.) of in the rhizosphere. In summary, exogenous
ECMF/DSE inoculation could increase P. tabulaeformis resistance to PWD probably by improving the rhizosphere microenvironment.