小杆线虫Rhabditis(Oscheius)sp.生物学特性测定

Determination on Biological Characteristics of Nematode Rhabditis(Oscheius) sp.

[目的]对从内蒙古自治区呼伦贝尔盟海拉尔市苜蓿根际土壤中分离出的小杆线虫[Rhabditis（Oscheius）sp．]的生物学特性进行测定。[方法]以大蜡螟（Galleriamellonella）和黄粉甲（Tenebriomolitor）老熟幼虫为寄主，测定小杆线虫的侵染力；以水浴方法测定小杆线虫的耐热能力。[结果l小杆线虫在10、20和40IJs／虫的剂量下侵染力较低；但在80、160、320和640IJs／虫的剂量下侵染力较高，大蜡螟96h、黄粉甲120h的校正死亡率均达90％以上；在80IJs／虫的剂量下侵染力最高，侵染120h，寄主的校正死亡率达100％。浓度1000～5000U／ml的小杆线虫在36℃条件下水浴2d，有25％左右的个体存活，水浴6d，仍有3％～9％的个体存活，至第9天，线虫个体全部死亡；在38℃下水浴6h、40℃下水浴2h，线虫个体全部死亡。[结论]小杆线虫具有较强的侵染力和耐热能力，具有开发应用潜能。

[ Objective] The study aimed to determine the biological characteristics of Rhabditis （Oscheius） sp. isolated from rhizosphere soil of alfalfa in Hailar City, Hulunbeir League, Inner Mongolia Autonomous. [ Method ] With mature larvae of GaUeria mellonella and Tenebrio molitor as the host, the infective ability of nematode was determined, and its heat tolerance ability was measured by using water bath method. [ Result] The infective ability of nematode was lower at the dosages of 10, 20 and 40 IJs/larva, but higher at the dosages of 80, 160,320 and 640 IJs/larva. The corrected mortality （CM） of G. mellonella at 96 h and T. molitor at 120 h were both above 90%. The nematode infective ability was highest at the dosage of 80 IJs/larva. The hosts＇ CM reached to 100% after 120 h infection. About 25% individuals could survive in 36 ℃ water bath for 2 d with the densities of 1000 - 5 000 IJ/ml, up to 6 d, there were still 3 % - 9% individuals survived, until 9 d, the nematodes died totally. A hundred percent of the nematode individuals died in 38 ℃ water bath after 6 h, in 40℃ water bath after 2 h. [ Conclusion] Rhabditis （ 0. ） sp. has the potential of development and application in higher host infection capacity and heat tolerance.