小杆线虫Oscheius tipulae JL1的鉴定及生物学特性

利用大蜡螟Galleria mellonella L.诱集法,从采自吉林省的土样中分离到小杆类昆虫病原线虫1种。经形态学、ITS及28S rDNA序列分析鉴定,明确了该线虫为Oscheius tipulae JL1。室内生物测定结果表明:24 h时,线虫JL1浓度为120 IJs/larva及以上时,大蜡螟的死亡率达90%以上;48 h时,浓度40 IJs/larva时,大蜡螟死亡率达93%以上;60 h时,浓度高于20 IJs/larva时,大蜡螟死亡率100%。耐热性方面,在38℃下处理8 h,线虫死亡率快速增加,35℃处理16 h,线虫死亡率开始快速增加。线虫JL1在35和38℃条件下,分别至少可耐16和8h的高温,死亡率分别在3.2%和15.3%以下。结果表明该线虫具有较好的耐热力、侵染力和致死力,未来有望用于害虫防治。

Identification and Biological Characteristics of Oscheius tipulae JL1

An entomopathogenic nematode isolated from soil samples collected from Jilin Province, China with the Galleria mellonella traps was identified as Oscheius tipulae JL1 strain using morphological, ITS and 28S rDNA sequence analysis. Biological assay showed that mortality of G. mellonella was more than 90% at 24 h exposure to nematode concentration of over 120 IJs/larva, reached 93% at 48 h exposure to nematode concentration of 40 IJs/larva, and was up to 100% at 60 h exposure to nematode concentration of over 20 IJs/larva. The nematode showed certain thermal resistance, with mortality of below 15.3% and 3.2% at 8 h exposure to 38℃ and at 16 h exposure to 35℃, respectively. When the thermal stress was stronger, nematode mortality increased rapidly. The results show that JL1 has adequate thermal tolerance, high infectivity and pathogenicity, and is potential for utilization in insect pests control.