Materials and methods Tian Yan 1, Tianyan No.2, 108, 1 10 were used as materials, and their young leaves were used as explants.

In vitro culture system was established with leaves of fast-growing poplar as explants. The results showed that adventitious buds easily occurred in veins and petioles. Buds are mostly produced directly from leaves; BA concentration in culture medium is the key to affect the formation of adventitious buds; BA can produce adventitious buds in the range of 0.5 ~ 2.0 mg/L. The combination of BA 1.0mg/L and NAA0.05mg/L is beneficial to the formation of adventitious buds. Adding ga 30.1~ 0.2 mg/l to the medium can increase the frequency of adventitious buds, and the proliferation medium is MS+Ba0.5 mg/L+NAA0.05 mg. In the process of rooting, the effect of transitional culture is better. The addition of ABT3 rooting powder greatly improved the quality of test-tube seedlings. On this basis, the in vitro regeneration system of poplar leaves was established. With this system, higher bud regeneration frequency can be obtained, but there are some differences among different varieties.