松材线虫病病程特征变化的研究

为提高从松树病死木上取样分离松材线虫的检出率，及时、准确诊断疫木和疫点，根据病害的外部症状，把松材线虫病发病过程分为四个阶段，对各阶段的松材线虫分布、松褐天牛发生情况、含水率的变化、木材蓝变情况等特征进行研究。结果表明：病死木上松材线虫的分布由多到少为：发病前期上部>中部>下部，后期上部<中部<下部，松材线虫的数量与松褐天牛老熟幼虫的数量呈正相关，最佳的取样阶段为第Ⅱ和第Ⅲ阶段靠上部稍段取样，第Ⅳ阶段偏下部取样。

Study on the Characteristics Variation of Disease Progression by Pinewood Nematode (Bursaphelenchus xylophilus Nickle)

In order to improve the efficiency of detect the pine wood nematode from pinewood, and definitude the process of pine wilt disease in the sampling characteristics. According to the external characteristics , the disease progression by the pinewood nematode (Bursaphelenchus xylophilus Nickle) was divided into 4 stage. The density changes of pine sawyer beetles (Monochamus alternatus Hope ), the water content and blue staining of the pine wood, and the distribution of the pine wood nematode in different disease stages had been obseved. The results showed that the spatial distribution pattern of pine wood nematode in the pine trunk is the top > the middle >the base in the initial stages, and the base >the middle >the top in the terminal stages. There was positive correlation between the quantity of pine sawyer beetles mature larva and the pine wood nematode.The best sampling phase is the upper section in the second and third stage and the lower section in the end of disease .