拟松材线虫(Bursaphelenchus mucronatus)为伞滑刃属植物寄生线虫,在形态上与引起松树萎蔫病(Pine Wild Disease)的松材线虫(B. xylophilus)极其相似。为探讨拟松材线虫的致病力与其体内细菌的关系,笔者将来自中国7省市不同地区的10个拟松材线虫虫株接种黑松测定其致病力,并对拟松材线虫的体内细菌进行了分离鉴定。结果表明,供试的10个拟松材线虫虫株中有6个虫株对黑松具致病力,4个虫株无致病力。通过分离拟松材线虫的体内细菌,发现有9个虫株体内存在细菌,共分离获得17株细菌,仅有1个虫株体内未分离到细菌。综合细菌菌落形态、生理生化指标、Biolog 96 孔碳源及16S rDNA序列分析对分离所得细菌进行了鉴定,结果从不同拟松材线虫虫株体内共鉴定出9属9种细菌,分别为嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)、美洲爱文氏菌(Ewingella americana)、荧光假单胞菌(Pseudomonas fluorescens)、根癌农杆菌(Agrobacterium tumefaciens)、Luteibacter anthropi、氧化微杆菌(Microbacterium oxydans)、Agreia pratensis、长野雷弗森菌(Leifsonia naganoensis),以及木糖氧化产碱菌木糖氧化亚种(Achromobacter xylosoxidans ssp. xylosoxidans)。对黑松有致病力的拟松材线虫多数虫株体内细菌的种类及数量多于无致病力的虫株,且能分离到嗜麦芽窄食单胞菌(S.maltophilia)的多数虫株均具有致病力,无致病力虫株的体内细菌主要为氧化微杆菌(M. oxydans)等。Bursaphelenchus mucronatus is one of plant parasitic nematodes and similar to the causative agent of pine wilt disease B. xylophilus in morphology. To understand the interaction between B. mucronatus and endobacteria, ten strains of B. mucronatus from seven provinces were inoculated to 2-year old Pinus thunbergii to evaluate their virulence. Besides, endobacteria of B. mucronatus were also isolated and analyzed. Pathogenic measurement showed that six strains of B. mucronatus were pathogenic to P.thunbergii, but the other four strains had no pathogenicity. Seventeen strains of endobacteria were isolated from 9 of 10 B. mucronatus strains. Physiological and biochemical characteristics, biolog methods combined with molecular revealed that seventeen strains of endobacteria belonged to Stenotrophomonas maltophilia, Ewingella americana, Pseudomonas fluorescens, Agrobacterium tumefaciens,Luteibacter anthropi, Microbacterium oxydans, Agreia pratensis, Leifsonia naganoensis and Achromobacter xylosoxidans ssp. xylosoxidans. Further analysis showed that species and population of endobacteria strains from virulent B. mucronatus strains were more abundant than that from non-virulent strains. S. maltophilia were usually isolated from virulent B. mucronatus strains, while endobacteria M. oxydans were mainly isolated from avirulent strains
