中文摘要：

为了解不同松材线虫虫株在致病性方面的差异，选用分离自日本和中国浙江的松材线虫虫株，分别接种雪松、黑松和马尾松．比较其感病情况，并在不同时期分离树体内的线虫，比较不同虫株在不同寄主体内的移动和分布情况。结果表明，2个日本虫株和1个中国虫株都能使黑松和马尾松感病和枯死，3虫株对黑松和马尾松的致病力没有明显差异：日本松材线虫虫株能使雪松枯死，枯死率在50％左右；中国松材线虫虫株不能使雪松致病．但在其体内可以分离到松材线虫。不同时期分离各寄主体内线虫发现．接种72h前线虫数量处于调整期，接种144h后线虫数量开始上升或下降。日本虫株接种雪松后，线虫数量呈递增趋势；中国虫株接种雪松．线虫数量在接种144h后开始下降。我国雪松不感染松材线虫病是由于线虫虫株发生了变异。

英文摘要：

In order to understand the difference in pathogenicity of different isolates of Bursaqhelenchus xylophilus, three isolates of nematode from Japan and China were inoculated in three trees of Cedrus deodara, Pinus thundergii and P. massoniana for comparing the susceptibility, the spread and movement of nematodes in different hosts. The results showed that three isolates of nematode were no differences in pathogenicity in P thundergii and P massoniana, two isolates of nematode from Japan and one from China could make the P. thundergii and P. massoniana wilted and died, the pathogenicity of three isolates of nematode were no differences in the trees of P. thundergii and P. massoniana. Inoculated with the isolates from Japan could lead Cedrus deodara wilted or died （mortality rate 50%）, but none of Cedrus deodara wilted or died inoculated with the isolates from China. The experiment separated the nematodes in different hosts and periods found that the amounts of nematode were at the adjustment period after inoculated 72h, and the amounts began to rise or fall after 144h. The amounts of nematode from Japan increased after had been inoculated, but the amounts of nematode from China began to decline after inoculated 144h in Cedrus deodara. The research also showed that the variation of the Bursaphelsnchus xylophilus lead the Cedrus deodara survival in China.