中文摘要：

将松材线虫携带的致病细菌无细胞滤液、无菌松材线虫和致病细菌混合物、致病细菌鞭毛蛋白无细胞滤液、无菌松材线虫、无菌松材线虫和非致病细菌混合物接种黑松导致的松树萎蔫的病状与野生松材线虫导致松树萎蔫的病状进行观察和对比，结果为：（1）经培养的致病荧光假单孢菌GcM5—1A菌株的无细胞滤液、无菌松材线虫和致病细菌GcM5—1A混合物接种导致的黑松的病状变化趋势与松材线虫致死的黑松病状是一致的；无菌松材线虫、无菌松材线虫和非致病细菌AM2C混合物不能使黑松发病；（2）致病细菌GcM5—1A无细胞滤液和野生松材线虫导致的黑松病状和病程天数无显著差异；（3）接种无菌松材线虫和致病细菌GcM5—1A混合物的黑松病程显著长于接种野生松材线虫的黑松。结果可以用松萎蔫病是松材线虫和其携带的细菌的复合侵染病害的假说和松材线虫与其携带的细菌之间的互惠共生关系的论点来解释．说明松材线虫携带的致病细菌无细胞滤液是松萎蔫病致病的真正原因。

英文摘要：

External symptoms were observed and compared in Pinus thunbergii inoculated with different inoculants including cell free filtration of the liquid culture of the pathogenic bacterium, Pseudornonas fluorescens GeM5 - 1A strain, carried by Pine Wood Nematode （ PWN）, Bursaphelenchus xylophilus, the mixture of aseptic B. xylophilus and the pathogenic bacterium strain, aseptic B. xylophilus and the mixture of aseptic B. xylophilus and the non -pathogenic bacterium, Staphylococcus lentus AM2C strain. The main results are as follows ： （ 1 ） External symptoms of P. thunbergii inoculated with cell free filtration of the pathogenic bacterium GeM5 -1A were consistent with those of the trees inoculated with wild PWN in external symptoms. However, the external appearances of the trees inoculated with aseptic PWN and those of the trees treated with the mixture of aseptic PWN and the non- pathogenic bacterium,Staphylococcus lentus, AM2C were the same as those of the healthy P. thunbergii; （2）The symptoms and time （d） to show them between trees inoculated with cell free filtration of the pathogenic bacterium GeM5 - 1A and those inoculated with wild PWN were not significant; （3） The whole disease process in trees of P. thunbergii inoculated with the mixture of aseptic PWN and the patho genie bacterium GeM5 - 1A lasted significantly longer than that of those inoculated with wild PWN. The results above can be explained by the hypothesis, pine wilt disease is a complex one induced by both PWN and the pathogenic bacteria carried by it and the mutualistie symbiotic relationship between PWN and the pathogenic bacteria carried by it. And it is also demonstrated that the toxic materials produced by the pathogenic bacteria carried by PWN are the very causes of the wilt.