Research On Bt Gene Transformed Into Chrysanthemum To Kill Longhorn Beetles

Chrysanthemum which are the most popular flower in world have long history in our country. They can cure people as medicine besides enjoyment function. However, there are many kinds of pests which are destroying chrysanthemum heavily, especially Phytoecia rufiventris Gautier. When chrysanthemum are sold, pests could affect the results, so we need to preserve chrysanthemum by using healthy insecticide. mBt886Cry3Aa, which is toxic to Coleoptera insects, was transformed into chrysant- hemum. Toxic effects of these transgenic plants to longhorn beetles were further dete- cted. The results were as follows,1. Construction of chrysanthemum genetic transformation regeneration systemThe mediums for genetic regeneration system were screened by choosing stems and apex as explants. The results showed that, the best one was MS + 6-BA 0.25 mg·L-1 + NAA 0.1 mg·L-1, in which the differentiated plants were healthy with 100% regeneration percentage. The best medium for rooting was 1/2MS + NAA 0.05 mg·L-1, in which the roots were long and crude with 100% rooting percentage. The effects of antibotics (Kanamycin and cefotaxime) on plants growth were also studied. The results showed that 15 mg·L-1 kanamycin significantly have an inhibition effect to the shoots regeneration. 10 mg·L-1 kanamycin totally inhibitted rooting. 400 mg·L-1 cefotaxime could not only inhibit the growth of non-transformation agrobacterium effectively, but also have no any effect on shoots growth.2. Transformation of recombinant including gene mBt886Cry3AaGene mBt886Cry3Aa was transformed into agrobacterium successfully by using PCR checking, and achieved 7 transgenic plants.3. Agrobacterium mediated- transformation of recombinantChrysanthemum stems were infested with transformed agrobacterium, then cultivated on regeneration culture medium including 15 mg·L-1 kanamycin and 400 mg·L-1 cefotaxime at 16h/8h photoperiod and 25℃temperature. The plants were layed on rooting medium including 10 mg·L-1 kanamycin. The plants can be planted outside after about 8 cm length. 7 positive plants were got by PCR checking at last.4. Biology testament of transgenic chrysanthemum on longhorn beetles Artificial feed and transgenic plangts were mixed to raise 2nd instar larvae accor- ding to one to ten. B1, B2, B3, B4 represent transgenic chrysanthemum respectively. The results showed that the mortalities of transgenic plants B4, B2, B3 to 2nd instar larvae were apparent compared with ck. In which the best one was B4 with 60% mortality, the following were B2 and B3 with 53.33% and 46.67% mortality respectively, compared with that of B4, which was 40%. Though the difference between B1 and ck was not apparent, it was bigger than ck.