Storage of osmotically treated entomopathogenic nematode Steinernema carpocapsae

• 来源期刊: 中国昆虫科学（英文版）
• 关键词: Entomopathogenic nematode heat tolerance osmotic Steinernema carpocapsae storage
• 年，卷（期）: 2006,（4）
• 页码范围: 263-269
• 页数: 7页
• 语种: 英文

摘要

The infective juveniles (IJs) of Steinernema carpocapsae 'All' were osmotically stressed by a mixture of ionic (fortified artificial seawater) and non-ionic (3.2 mol/Lglycerol) solutions to establish a method for osmotic storage of entomopathogenic nematodes.Seven combinations (termed solution A to G) with different proportions of these two solutions were tested, with sterile extra pure water (sepH2O, termed solution H) as a control. The mortality of the IJs at a concentration of 5 × 105 IJ/mL in the solutions A to G, and H were 13.2%,16.2%, 16.7%, 13.5%, 25.2%, 31.6%, 44.6%, and 1.0%, respectively, after 21 days storage at 25℃. Most of the IJs shrunk and stopped motility after 6-9 hours incubation at 25℃ in solutions A to D. Based on the results, solutions A to D and H were chosen to further test the osmotic survival of the IJs at different IJ concentrations (5×105, 2.5 × 105, 2000 IJ/mL) and incubation temperature (30℃, 25℃, 10℃). The resulting IJs were exposed to a high temperature assay (45℃ for 4 h, HTA). Osmotically stressed IJs showed improved heat tolerance. The mortality of the IJs increased with the increasing concentrations of the test IJs and the storage temperatures after exposing to the HTA. More than 88.4%, 62.3% or 2.4% of the treated IJs died at the above three IJ concentrations, respectively. At the three IJ concentrations (2 000 IJs/mL, 2.5 × 105 IJs/mL or 5 × 105 IJs/mL), the highest mortality was recorded in solution D (11.6%, 85.9% or 98.0%, respectively), and the lowest mortality in solution B (2.4%, 62.3% or 86.6%, respectively). No untreated IJs survived after the heat treatment. During 42 days storage at 10℃, the IJs mortality in the solutions A to D and H were 7.19%, 5.97%,4.41%, 4.34%, and 4.34% respectively, and showed no significant differences. In conclusion,solutions enhances the heat tolerance. The mortality of the IJs after HTA increased with the increasing concentrations of the test IJs and the storage temperatures after exposure to the HTA.The result is promising for the osmotic storage of the entomopathogenic nematodes.