【摘要】 采用叶片浸渍法测定了嗜线虫致病杆菌(Xenorhabdus nematophila) HB310菌株对不同龄期东亚飞蝗蝗蝻(若虫)的口服胃毒活性。结果表明,菌液与细胞在相同浓度条件下对2龄和4龄蝗蝻杀虫活性无显著差异,但明显高于上清液活性(P<0.05);在高浓度(2.24×10~6cfu/mL)条件下,菌液和细胞对东亚飞蝗成虫致病力无差异,但随着浓度降低,菌液的活性明显高于细胞和上清液,且东亚飞蝗龄期越小敏感性越强。该菌株不同分子量胞内蛋白粗提物对不同龄期东亚飞蝗蝗蝻均具有很好的胃毒活性。其中,30 kDa蛋白粗提物饲喂处理96 h后,不同龄期东亚飞蝗蝗蝻的死亡率均达到90%以上。更多还原

【Abstract】 In this study, the stomach activities of mixed suspension, b acterial cells and supernatant from Xenorhabdus nematophila HB310(X. n HB310) cultures against different instars of Locusta migratoria manilensis were determined by the leaf dipping method. At the same concentration, the insecticidal activities of the mixed suspension and bacterial cells against the 2 nd and 4 th instar nymphs were not significantly different, but they were significantly higher than that of the supernatant. Under high concentration(2.24×10~6 CFU/mL), there was no difference between the mixed suspension and bacterial cells in insecticidal activity against adults. However, as the concentration decreased, the insecticidal activity of the mixed suspension was significantly higher than that of the bacterial cells and supernatant. The younger the nymphs,the more sensitive they were to X. n HB310. Further, the stomach activities of X. nematophila HB310 intracellular proteins of different molecular weights against L. migratoria manilensis were determined, resulting in over 90% mortality rates of L. migratoria manilensis at different instars after feeding with the intracellular protein of 30 kDa for 96 h.更多还原