Abstract: 【Objective】 The objective of this study is to transform mBtCryAa into chrysanthemum; which has resistance to long-horned beetles; and determine the toxic effect of transgenic plants to Phytoecia rufiventris Gautier. The results of the study will provide a new way to control Coleoptera pests. 【Method】mBtCryAa was transformed into chrysanthemum mediated by Agrobacterium tumefaciens according to the best culture media and the best suitable kanamycin and cefotaxime concentration confirmed for chrysanthemum differentiation and rooting; then artificial feed and transgenic plants were mixed to raise nd instar larvae. 【Result】 Seven transgenic plants including mBtCryAa were obtained by kanamycin riddling and PCR; and four strong transgenic plants mixed with artificial feed were used to raise nd instar larvae. The results showed that the mortality rates between transgenic plants and control were significantly different. 【Conclusion】 Bioassay indicated that the transgenic plants had better toxic effects on nd instar larvae.

Key words: chrysanthemum, Phytoecia rufiventris Gautier, regeneration system, Bt gene, bioassay