Abstract:

Platanus acerifolia is a famous shade tree, which plays a very important role in city afforestation. In this paper the P. acerifolia leaf regeneration system was thoroughly discussed for the first time. The leaves of P. acerifolia were used as the experimental material. Several factors such as hormone concentration, explant condition, illumination condition, and so on were investigated to optimize the regeneration system in vitro. The experimental results showed that leaf situation can greatly affect P. acerifolia regeneration frequency. The best explants were those 40 days apical leaves from the cultured plantlets. The high frequency of shoot regeneration was observed when leaf explants were cultured on MS medium supplemented with 1.5 mg·L^-1 6-BA, 0.5 mg·L^-1 IBA and 0.5 mg·L ^-1 KT. First, the leaves were cultured in dark. After 7 days the explants were transferred under light and began to directly regenerate adventitious buds in about 15 days. The maximum number of the adventitious buds was observed within 20 to 30 days. The shoot differentiation frequency was more than 98%. When the shoots grew to 1～2 cm high, they were cut from leaves, then transferred on to shoot elongation medium (MS+0.3 mg·L ^-1 6-BA+0.05 mg·L^-1 NAA+30 mg·L^-1 Ad)until plantlets coming into being. Finally, the plantlets were rooted on the root differentiation medium (1/2MS+0.1 mg·L ^-1NAA) and developed into whole plants within 14 days. This regeneration system can be applied to P.acerifolia transgenic manipulation.

Key words: Platanus acerifolia, Leaf, Plant regeneration, Tissue culture