Studies on complex infecting of pine wood nematodes and the bacterium carried by it

In order to clarify pathogenicity mechanism of pine wood disease,Bursaphelenchus xylophilus,Bursaphelenchus mucronatus,Aphelenchoides sp.,Rhabditida were separated from pine trees and two bacterial isolates(Pseudomonas fluorescens and Enterobacter aerogenes) were separated from B.xylophilus and Rhabditida.The aseptic seedlings and callus of black pine(Pinus thunbergii) were inoculated with aseptic nematodes and two bacterial isolates.The results indicated that the aseptic B.xylophilus and B.mucronatus can lead to wilting of aseptic black pine seedlings and browning of callus only integrated with virulent P.fluorescens,while aseptic B.xylophilus,B.mucronatus or P.fluorescens cannot cause black pine to death when inoculated separately.The bacterium spread in the pine trees carried by the nematodes and caused pine trees to death.This study further testified the nematode and bacterium interact in the course of causing black pine to death.