松材线虫病发病过程特征变化的研究

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

为提高松树病死木松材线虫检出率,及时、准确诊断疫木和疫点,根据病害的外部症状,把松材线虫病的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:在发病前期,上部>中部>下部;发病后期,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阶段靠上部梢段取样,第Ⅳ阶段偏下部取样。

According to the external characteristics, the disease progression was divided into 4 stages. In each stage, the density changes of pine sawyer beetles （ Monochamus alternatus Hope ）, the water content and blue staining of the pinewood, and the distribution of the pinewood nematode was observed. The results showed that in the initial stages, the pinewood nematode in trunk distributed most in the top , then decreased form up to low. Well in the terminal stages, there is a contrary situation, the pinewood nematode distribuite most in the base trunk but least in the top trunk. There was a positive correlation between the quantity of the pine sawyer beetles mature larva and that of the pinewood nematode. The best sampling parties for the Ⅱ and Ⅲ stage are upper shoot section. Well section near the base trunk is suitable for the stage Ⅳ.