松材线虫病程中树体内线虫和细菌种群数量的动态变化

Dynamics of Populations of Nematode and Bacteria in the Process of Pine Wilt Disease

越来越多的证据证明松材线虫病是由松材线虫和线虫携带的细菌共同引起的。本文对接种松材线虫后黑松的不同发病阶段 ,树体内非接种枝上的线虫、细菌的种类及数量变化动态进行了研究 ,结果表明 ,非接种枝上 ,在病树出现少量黄色针叶时 ,能有细菌检出 ;较多黄色和褐色针叶时 ,线虫才开始出现 ,细菌开始增多 ;至发病后期 ,病树基本枯死时 ,线虫和细菌数量迅速增加。对发病过程中出现的细菌种类鉴定表明 ,发病中期 ,细菌种类比较单一 ,随着病情的发展 ,细菌不但数量迅速增加 ,而且种类也增多 ,但优势菌群为荧光假单胞菌、假单胞菌 不动杆菌。

Recently more and more evidence confirmed that pine wilt disease were caused by both Pine Wood Nematode and its carrying bacteria. Dynamics of population of nematode, variety and the quantity of bacteria in non-inoculated branches along with the process of the disease were observed firstly through inoculated with Pine Wood Nematodes onto testing Black Pine trees. In non-inoculated branches, bacteria could be detected when few pine needles became yellow; while most needles changed into yellow or brown, nematode could be isolated and the quantity of bacterium was increased; in the end, when the testing tree was dying and needles were totally wilted, the populations of both nematode and bacteria were increased rapidly. According to the identification of the bacteria isolated from the testing trees, the numbers of the isolated bacteria species were small, only a few, at the first and the middle stages. As the disease was developing, bacteria increased not only in their quantity, but also in amount of species. However, the domination species remain the same, they are Pseudomonas fluroescens, Pseudomonas sp.Acinetobacter sp., Pantoea sp. and Sphimgomenas pancimobilis.