白僵菌是一种优良的生物工程菌,鉴定和筛选高毒力的菌株能够促进检疫性害虫稻水象甲的防治。对8个不同的球孢白僵菌菌株进行人工接种分析。结果表明这些菌株对稻水象甲均具有毒性。接种后的15 d累计虫口死亡率为44.3%~88.3%,8个菌株的毒杀效果有显著差异,其中效果最好的为Bb-3。此外菌株对稻水象甲的毒杀效果明显与孢子的剂量呈正相关。同时发现被感染的稻水象甲对水稻危害下降,其取食斑数和长度显著低于对照。研究结果提出筛选高毒力的球孢白僵菌菌株,利用高剂量的孢子悬浮液接种害虫是防治稻水象甲的一种重要方法。%Beauveria sp.is an elite bioengineering bacterium against insect pests for protecting crops .It is important to screen the high toxicity B.bassiana against Lissohoptrus oryzophilus ( an invasion insect pest ) for protection of rice produce .In this study, eight B. bassiana strains were employed to assay the toxicity against L.oryzophilus through feeding rice tissues .The results showed that all strains had various potential toxicities to L.oryzophilus, mortality rates of pest infected with various B.bassiana strains showed obvious difference with 44.3%-88.3%at 15 post inoculation , of which , Bb-3 exhibited the highest toxicity .Additionally , the toxic effect of B.bassiana against L.oryzophilus was positively related with spore content applied .Furthermore , the L.oryzophilus infected with Bb-3 reduced the damage to rice tissue compared to the control including number of feeding scars and length of scar .Together, the data suggest that the identification of high toxic B.bassiana strains and high dose spore application are two key factors against L.oryzophilus for protecting rice produce .
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