松材线虫病的潜伏侵染及松墨天牛传播新途径

The Latent Infection of Bursaphelenchus xylophilus and A New Transmission Way of PWN by Monochamus alternatus

在南京用松材线虫接种 7种松树 ,于第 2a在无任何症状的松树的接种点上方 10cm处取样 ,分离线虫。结果表明松材线虫病的潜伏侵染现象比较普遍。在不同的松树品种上潜伏侵染现象有所差异。感病黑松和赤松很快死亡 ,只有在接种量小的情况下才有潜伏侵染现象发生。抗病性强的火炬松和湿地松感病后潜伏侵染现象比较普遍 ,并且样品中的线虫量也较高。而抗病性中等的马尾松和刚松感病后潜伏侵染现象的普遍性及样品中的线虫量均处于中等。短针松接种松材线虫后既不枯死 ,也无潜伏侵染现象。松墨天牛传播松材线虫的试验结果表明 ,未携带松材线虫的松墨天牛成虫在松材线虫病松枝上取食后 ,再到健康松枝上取食 ,有传播松材线虫的可能。这些结果表明在松材线虫病新病区清理病死木时 ,应采取早期诊断技术 ,把未表现症状的松树一起清除 ,以达到防治目的。

Seven pine species were inoculated by pine wood nematode (PWN) Bursaphelenchus xylophilus at Nanjing, in next year the samples were taken above the inoculate sites of alive pines which did not have any outer symptom and isolated nematodes. The result showed that the latent infection of PWN was more common. and it varied on different pine species. After inoculation the susceptible pines, Pinus thunbergii and P. densiflora , died fast. When the inoculum dose was very small, the latent infection could happen. For resistant pines, P. taeda and P. elliiottii , the latent infection was more common and the PWN number in the samples was higher. For moderate resistant pines, P. rigida and P. massoniana , the universal level of latent infection and PWN number in the samples were mid. After inoculation P. echinata did not wilt and there were no any nematodes in the samples. The result of PWN transmission by Monochamus alternatus test showed that after maturition feeding of PWN free beetles on the pine branches inoculated by PWN, the beetles can carry PWN and transmit the nematodes to healthy pine branches.