DETERMINATION OF BACTERIAL NUMBER CARRIED BY A PINE WOOD NEMATODE AND CULTURE OF ASEPTIC NEMATODES ON CALLI OF PINUS THUNBERGII

The experiments demonstrated that the pine wood nematode [Bursaphelenchus xylophilus (Steiner Buhrer) Nickle] carried many bacteria. The average bacterial number carried by each nematode from naturally infected Japanese black pine trees, Pinus thunbergii, was more than 2.9×102 bacterial cells and from cultured by feeding mycelium of Botrytis cinerea Pers. grown on PDA 3.0×103 bacterial cells. The pine wood nematodes isolated from naturally infected pine trees, P. thunbergii and P. massoniana, were inoculated onto calli of P. thunbergii after disinfection. The experimental results showed that pine wood nematodes were propagated well on the calli and the population of nematodes reached more than 100 000 nematodes per flack containing 3 grams fresh weight of calli in 9 days after inoculation. This indicated that the culture of nematodes by using calli of P. thunbergii was a good way to obtain a large number of aseptic pine wood nematodes.