松材线虫体内细菌对宿主繁殖和致病力的影响

Effects of endobacteria on reproduction and virulence of Bursaphelenchus xylophilus

为探讨松材线虫体内细菌在松材线虫病中的作用,对无菌松材线虫、体内细菌处理的松材线虫和野生型松材线虫的繁殖量和致病力进行了测定。结果表明:在非寄生条件下,无菌松材线虫的产卵量、卵孵化率和繁殖量显著高于携带细菌的松材线虫;松材线虫体内寄生菌嗜麦芽窄食单孢菌NSPm Bx03胞外代谢产物对松材线虫产卵量具有一定抑制作用。不同处理的松材线虫接种到3年生马尾松后,其繁殖量从高到低为野生型松材线虫>体内细菌处理的松材线虫>无菌松材线虫。对马尾松发病情况观察发现:接种野生型松材线虫的马尾松发病最早,病程最短;次之为接种体内细菌处理的松材线虫;最后是接种无菌松材线虫的处理。这表明嗜麦芽窄食单胞菌NSPm Bx03对松材线虫在寄生和非寄生条件下繁殖的影响不同,对松材线虫致病力有一定增强作用。

To investigate the role of endobacterium in the pine wilt disease,the reproduction and virulence of non-parasitic Bursaphelenchus xylophilus,B. xylophilus treated with endobactria and wild-type B. Xylophilus were measured. We found that the spawning number,hatching rate and reproduction number of aseptic B. xylophilus was higher than B. xylophilus treated with bacteria in non-parasitic condition. Extracellular metabolism of endobacterium could inhibit the reproduction of B. xylophilus. After inoculated with 3 years old Pinus massoniana,the reproduction number of nematodes from high to low was as follow： wild-type B. xylophilusB. xylophilus treated with endobacterium aseptic B. xylophilus. The pines that inoculated with wild-type B. xylophilus firstly occurred wilting and the course of disease was the shortest in the three different treatments of B. xylophilus. Secondly,the B. xylophilus treated with endobacteria appeared wilting,and the aseptic B. xylophilus appeared lastly. These results indicated that endobacterium exerted different effect on the development of B. xylophilus in non-parasitic and parasitism condition and could enhance the virulence of nematode.