摘要： 为了发掘新的Bt资源,从河北省不同果园中(板栗、葡萄、枣、梨)采集土样71份,利用醋酸钠-抗生素筛选法从中筛选出41株Bt菌株.采用通用引物进行PCR扩增鉴定基因型,结果表明,从这些菌株中发现6种不同的基因型cry1、cry7、cry8、cry19、cry26-28、cry32,还有2个菌株未鉴定出基因型.通过SDS-PAGE检测显示,大多数Bt菌株主要蛋白条带分子量约为130 kDa.生物活性测定结果表明,XPZ-6、XPZ-8、XPZ-9、XPZ-39、XPZ-42菌株对小菜蛾、棉铃虫、玉米螟和美国白蛾具有高活性,其中XPZ-39菌株的杀虫活性最高,对4种鳞翅目害虫的杀虫活性均达到97%以上.尽管XPZ-28和XPZ-46菌株的cry基因型未被确定,但是两个菌株分别对柳蓝叶甲和蓼蓝齿胫叶甲有一定的杀虫活性.

关键词: 苏云金芽孢杆菌, cry基因, 杀虫晶体蛋白, 杀虫活性

Abstract: Bacillus thuringiensis(Bt) is most widely studied and used as insecticidal microbe for its high insecticidal activity and safety. In order to search new Bt source，71 soil samples were collected from different orchards of Hebei province in China including pear orchards，g rape orchards，jujube orchards and chestnut orchards. 41 Bt isolates were obtained from 71 soil samples using sodium acetate via antibiotics method. These Bt isolates were characterized based on their insecticidal activity，crystal protein shape，sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ，and PCR analysis using novel general and specific primers for cry genes. Six types of cry gene，cry1， cry7，cry8，cry19，cry26-28 and cry32，were found in 39 Bt isolates，There ware still two Bt strains which cry gene of did not be identified. Most isolates showed a major protein band of 130 kDa in SDS PAGE gel. The spore-crystal mixtures of XPZ-6，XPZ-8，XPZ-9，XPZ-39 and XPZ-42 strains all showed high toxicity against the larvae of Plutella xylostella， Helicoverpa armigera，Ostrinia furnacalis and Hyphantria cunea，moreover，the insecticidal activities of XPZ-39 strain were highest (＞ 97% mortalities) . XPZ-28 and XPZ-46，cry genes of which did not identified，showed insecticidal activities to larvae of Plagiodera versicolora and Gastrophysa atrocyanea respectively.

Key words: Bacillus thuringiensis, cry gene, Insecticidal crystal proteins, Insecticidal activity

中图分类号: 

• S43