【Abstract】 This paper reports a successful transformation of chitinase gene into Populus simonii×P. nigra by Agrobacterium-mediated means. For reducing adventitious buds,the optimal concentration of kanamycin was 40 mg·L~ -1 . Up to 700 mg·L~ -1 of Cefazolin Sodium had no obvious effect on differentiation of leaves. About 20-day-old leaf disc explants were pre-cultured for 3-4 d,then immersed in Agrobacterium suspension for infection for 6-15 min,then co-cultured on non-selection culture medium for 3 d in the dark at 25 ℃. At last,the explants were transferred to the selection culture medium (containing kanamycin 40 mg·L~ -1 and Cefazolin Sodium 700 mg·L~ -1 ) in light at 25 ℃. RT-PCR analysis showed that 8 of 13 transgenic plants,which were screened by PCR and PCR-Southern blot analyses,had target bands. This result confirmed that the target gene had been integrated into genome of Populus simonii×P. nigra and expressed stably on the level of transcription. Chitinase activity of most transgenic plant leaves was higher than that of non-transgenic plants obviously,and No.11 transgenic plant had 3.093 times chitinase activity of the control plant.更多还原