中文摘要：

[目的]Cry1B类杀虫蛋白对鳞翅目和鞘翅目昆虫具有较好的杀虫活性,具有广阔的应用前景。为进一步挖掘并研究Cry1B类蛋白。[方法]本文使用一对引物对24个Bt菌株进行定性PCR反应,尝试筛选新的cry1B基因。该引物能够扩增包括Cry1B蛋白N-端3个结构域在内的718个氨基酸编码序列。[结果]共有8个菌株包含cry1B基因,约占筛选菌株的33.3%。序列分析发现,获得8个基因中有6个为新基因,其中6-1和15-1基因编码氨基酸序列与Cry1Bd1完全相同;9-1、10-1、18-1、20-1和21-1对应氨基酸序列与Cry1Bd1的一致性≥98.5%;而4-1基因编码的氨基酸序列与Cry1Bb1和Cry1Bc1蛋白N-端仅差1个氨基酸,需要进一步鉴定C-端长尾的编码序列以判断其所属亚类。[结论]本研究获得6种新型Cry1B蛋白基因,为进一步解析这类蛋白的杀虫活性和机理提供了丰富的材料。

英文摘要：

[Objective]Cry1Btoxins from Bt strains are toxic against some lepidoptera and coleopteran pests and therefore are good candidates for insect pest management.In this paper,we screened newcry1 Bgenes from 24 Bt strains.[Methods]PCR method was used for new genes screening and the chosen primer pair can amplified the sequences encoding the 718 amino acids of N-terminal of Cry1 Bproteins.[Results]The results showed that about 33.3per cent strains（8of 24strains）contained cry1 Bgenes.Sequencing analysis revealed that 6-1 and 15-1 genes encodes same polypeptides as Cry1Bd1.And 9-1,10-1,18-1,20-1 and 21-1 represented higher amino acid sequence identity than 98.5%with Cry1Bd1.There was only one amino acid difference between the deduced protein of 4-1 gene and N-terminal Cry1Bb1 or Cry1Bc1,so further identifying C-terminal encoding sequence would be necessary to conclude its classification.[Conclusion]In summary,we obtained 6novel cry1 B genes which can be ideal candidates for researching insecticidal activity and action mode of Cry1 Bproteins.