| As a sort of precious bio-pesticide resources,the isolation and charactization of Bacillus thuringiensis is,no doubt,of good value.718 Bt isolates stored in the lab are measured the toxincitiy to silkworms,and the lower toxic ones(14 isolates)are selected to measure the toxincity to Diaphania pyloalis Walker.In the end,final target isolate LY-250 is isolated.In the primary genetic diversity of LY-250,the research on the molecular charactization of LY-250 is taken to offer a basic-research for goods use.This paper is composed of two parts.1 The bioassay of Bacillus thuringiensisBasing on the 951 Bt isolates stored in our lab from 8 cigarette-factories in 6 different proviences all over china,718 isolates are at random are selected to find out isolates which have lower toxincity to silkworms.And then the 14 target isolates are selected to measure the toxincity to Diaphania pyloalis Walker.Finally,the target Bt isolates LY-250 is isolated,which is lower toxic to silkworms but higher toxic to Diaphania pyloalis Walker.2 the primary genetic diversity of LY-25The article gives a primary genetic diversity of LY-250,which includes the plasmid pattern,SDS-PAGE pattern and gene type analysis.The result shows tha LY-250 is different from the standard strain HD-1 in plasmid pattern;The SDS-PAGE pattern indicates that LY-250 habors the 130KD and 67KD ICPs;The gene type indicates that LY-250 at least habors cry1Aa,cry1Ab,cry1F three kinds of cry1 genes and cry2 gene. |
