预处理方式对昆虫病原线虫冷冻存活的影响
Effect of pretreatment method on freezing survival of entomopathogenic nematodes

【目的】探讨提高昆虫病原线虫冷冻存活能力的方法，以改进昆虫病原线虫储存技术。【方法】以我国高寒地区分离、筛选出的高致病力昆虫病原线虫Heterorhabditis bacteriophora HBN（HBN，45°45′N）和从美国引进的同种不同品系昆虫病原线虫H.bacteriophora NJ（NJ，40°13′N）为研究对象，在实验室条件下研究了不同预处理方式对2个品系线虫冷冻存活率的影响。【结果】HBN经过25 ℃ 7 d、10 ℃ 7 d、4 ℃ 7 d、25 ℃ 3 d 10 ℃ 3 d和25 ℃ 3 d 10 ℃ 3 d 4 ℃ 3 d的预处理后，于-4 ℃冷冻5 d时的存活率为86.1%～95.2%，显著高于直接冷冻法（25 ℃ 0 d）的存活率17.7%，而NJ经25 ℃ 3 d 10 ℃ 3 d 4 ℃ 3 d的预处理后，于-4 ℃冷冻5 d时的存活率为83.0%，显著高于其他预处理（2.2%～58.5%）。【结论】适当的预处理可提高2个品系线虫的冷冻存活率，但生活在不同地理纬度的同种线虫（HBN和NJ）适于不同的驯化方式。
【Objective】In order to improve storage technology of entomopathogenic nematodes (EPNs),the methods to increase freezing survival of EPNs were explored.【Method】Two strong virulence strains of EPNs,Heterorhabditis bacteriophora HBN (HBN) with cold tolerance isolated from Harbin (China,45°45′N) and H.bacteriophora NJ (NJ) from New Jersey (USA,40°13′N),were used in this study.The survival rates of HBN and NJ at -4 ℃ for 5 days after different pretreatment methods were compared.【Result】The freezing survival rates of HBN pretreated at 25 ℃ for 7 d,10 ℃ for 7 d,4 ℃ for 7 d,25 ℃ for 3 d then 10 ℃ for 3 d,and 25 ℃ for 3 d and 10 ℃ for 3 d before 4 ℃ for 3 d were 86.1% to 95.2%,which were significantly higher than that of 25 ℃ for 0 d (17.7%).The highest freezing survival rate of 83.0%,was obtained for NJ when pretreated at 25 ℃ for 3 d and 10 ℃ for 3 d before 4 ℃ for 3 d,which was significantly higher than those of other pretreatment methods (2.2% to 58.5%).【Conclusion】Freezing survival rates of HBN and NJ could be increased by appropriate pretreamtents.But the best pretreatment methods for the same species (HBN and NJ) isolated from different geographical latitudes were different