Insect Bioassay And Tentative Analysis Of Effects On Soil Microbial Flora Of Transgenic Poplus*Eramericana Cv 'Nanlin895' With Bt Or CpTI Gene

The area of poplar planting in china is the biggest around the world.But overcrop of one kind of poplar brings on serious hazards carsed by pests.It has no time to delay for cultivating new insect resistance poplar by genetic engineering technology.In this paper, Populus×eramericana cv 'Nanlin895',with Bt gene or CpTI gene,were used as experiment materials.PCR analysis,larvae bioassay and priliminary biosafty assessment were carried on,which would supply a basis for breeding new excellent species of poplar.The main results described as follows:1.Improvement of regenerate system of transgenic Populus×eramericana cv 'Nanlin895'with Bt gene or CpTI gene through the screening to the basic culture medium,the adjustment of hormone categories and concentration,election of the culture condition,the optimal medium for leaf differentiation was MS + 0.5mg/L 6-BA +0.002mg/L TDZ + 0.1 mg/L NAA.The optimal medium for bus inducement was MS + 0.2mg/L 6-BA +0.001mg/L TDZ+0.05mg/L NAA.The medium for rooting is 1/2 MS+24%sugar,which increased the ratio of poplar regeneration from 91%up to 100%,differentiation ratio from 11.6%up to 36.0%,and the system layed a solid foundation for PCR and insect bioassay;2.The period of poplar growing is long.In order to trace the inheritance and segregation of transformants,tissue culture of 4 years was carried on.11 transgenic Populus×eramericana cv 'Nanlin895'with Bt gene:B2,B17,B4,B1,B21,B16,B6,B8,B12,B3,B5 etc.were detected with PCR analysis.The analysis result showed that foreign gene was still carried in the genome of poplar and this provided a solid foundation for cultivating new kinds of insect resistant poplar;3.The larvae of Micromel alophatroglodyta(Graeser)were used in bioassay of 11 transgenic plant:B5,B7,B16,B2,B12,B4,B1,B17,B21,C4.The result of insect bioassay showed that all the transgenic plants were resistant to larvae at different levels.B4,B1,B17, B21 were confirmed extremely resistant to larvae,and the emending mortalitys were 25.6%, 24.0%,15.0%,12.0%(0%of CK).The leaf of transgenic poplar significantly restrained the weight of larvae,and the relative weight of insects feeding on B1,B4,B21,C4 descended more than 50.0%.And B1,B4,B21 remarkably produced negative influence on the larvae into chrysalis,the ratios descended more than 30.0%.Eclosion ratio of B4,B1,B7,B17,C4 decsended 25%at least;4.Today biosafty is the focus of public concerns.In order to understand the effects of transgenic organisms on soil microbial flora,this paper analyzed the number of actinomyces, bacterium,epiphyte of 5 different transgenic 895 with Bt or CpTI gene:B21,B1,B17,B4, C4.The priliminary results indicated that the number of bacterium,epiphyte,actinomyces was not significantly different.