越南枯死松树症状特征和体内寄生线虫种类调查

为确定造成越南松林的枯死是否为松材线虫所为,对越南南部的林同省、中部的承天-顺化省、北部的广宁省的思茅松(Pinus kesiya Royle)、马尾松(P. massoniana Lamb.)和南亚松(P. merkusii jungh et de Vries)松树枯死现象及症状特点进行了调查,分别从52株枯死、濒死、健康松树木质部中抽取木质部样品,进行线虫分离,根据形态学特点确定这些松树体内寄生线虫的种类。调查发现松树在枯死过程中,树冠部分针叶失去光泽,逐渐褪绿变黄,进而褐红干枯,最后整个树冠变为褐色或红褐色,全株枯死,针叶下垂且当年不落; 随着病程的发展,松脂分泌逐渐减少,直至停止; 树干上有天牛产卵刻槽,死亡的松树上有天牛的羽化孔。在抽取的松树样品中分离鉴定到了泰国伞滑刃线虫(Bursaphelenchus thailandae)、悬臂伞滑刃线虫(B. gerberae)、中华伞滑刃线虫(B. sinensis)、树木伞滑刃线虫(B. silvestris)、托斯卡纳伞滑刃线虫(B. tusciae)、莱奴尔夫伞滑刃线虫(B. rainulfi)、云杉小蠹伞滑刃线虫(B. rufipennis)和伞滑刃属线虫未定种(B. sp.),调查中未发现重要检疫性病原松材线虫(B. xylophilus)。

A survey on the symptoms and endoparasite of the dead pine trees in Vietnam

To probe into the causes for the death of pines in Vietnam, a couple of withered Pinus species like Simao pine(Pinus kesiya Royle), masson pine(P. massoniana Lamb)and Pinus latteri (P. merkusii Jungh et de Vries)from Lam Dong Province, Thua Thien-Hue Province, Quang Ninh Province were investigated. Nematodes were isolated from the wood xylem of 52 dead, dying and healthy pine individuls, and classified according to the morphological characteristics. The survey results showed that, during the process of dying, the needles of the pine tree crown part lost luster at early stage, then gradually turned into yellow followed with red color change and needle dried out, finally the whole crown of the pine turned into brown or reddish brown and the whole pine tree died, while the needles were drooping but not falling down in the first year. With the development of the disease, the rosin secretion gradually reduced and eventually stopped, the longicorn beetle made the oviposition cut marks on the trunk, the emergence holes appeared when the tree dead. Generally, the Thailand bursaphelenchus(Bursaphelenchus thailandae), the cantilever bursaphelenchus(B. gerberae), China umbrella aphelenchoides(B. sinensis), trees bursaphelenchus(B. silvestris), Tuscany bursaphelenchus(B. tusciae), Lainuerfu bursaphelenchus(B. rainulfi), spruce bark beetles bursaphelenchus(B. rufipennis)and bursaphelenchus nematode undetermined species(B. sp.)were identified in this study. We didn't find, the pine wood nematode(B. xylophilus)during the investigation.