Abstract:

The regeneration system of the hybrid triploid of Chinese White Poplar was established and the partly modified two insect-resistant genes BtCry1Ac gene and arrowhead proteinase inhibitor (API) gene were transformed to the hybrid poplar clone. After transformation, 18% leaves could be induced shoots in specific medium contained 50 mg·L^-1 kanamycin. The transgenic plants were selected further on the MS medium used for root induction added 50 mg·L^-1 Kanamycin and 50 transformed subclones were obtained. The transformed plants got by reaping selection were detected by PCR and 80% took on positive reaction. Some subclones were tested by southern blot and proved the exogenous gene has inserted in the poplar genome. Leaves of transformed plant were detected by ELISA using antiserum. The result indicated that the Bt toxoprotein was found in 7 transgenic subclones and the proportion of the Bt toxoprotein expressing to the total fusible protein was 0.001 1～0.016 1%, markedly higher than the control (0.000 6%). One-year old leaves of 28 subclones transformed with Bt-API genes successfully tested by molecular biological method, and were used to feed the Lymantria dispar and the Clostera anachoreta. Result indicated that 39.3% of tested plants (11 subclones) took on high resistance and the larvae mortality was over 80%; 25 percent (7 subclones) possessed relatively lower resistance and the mortality was 60%～80%; the other 10 subclones took on very low resistance with the mortality of below 50% and some even did not have any resistance. The transgenic plants with high insect-resistance could also obviously inhibit the development of the larvae.

Key words: hybrid triploid of Chinese White Poplar, two insect-resistant genes, gene transformation, resistance to insects