Callus induction and adventitious bud regeneration from leaves of rootstock of sweet cherry in vitro

The rate of adventitious bud regeneration from explants is highly correlated to the efficiency of gene transformation. In order to set up the stable and high efficient system of adventitious bud regeneration in cherry, the factors affecting adventitious bud regeneration from leaves and stems in vitro were studied in the ZY-1 (Prunus cerasus L.), which is used as a rootstock of sweet cherry, including the types and concentration of plant growth regulators applied in the culture media, the types of explants, the laying modes of leaves, and the incubating condition. The young leaves sampled from the top of shoots and stems without buds attached were used, and both of them were collected from the plantlets sub-cultured in vitro for 30~40 d. The results showed that the rate of adventitious bud regeneration and the number of adventitious buds per leaf were higher on the media that supplied 7.0 mg/L 6-BA and 0.5~1.0 mg/L IBA. The positive results was not obtained by using TDZ and NAA in term of the adventitious bud regeneration in this experiment. The stems as explants generated more adventitious buds than the leaves. The young leaves, which were cut two times and placed on the medium with the lower surface touching the medium, showed higher regeneration rate. The adventitious buds were easier to generate from the leaf disks that were cut from the base part of the leaves and had the petioles attached. The conducting of dark incubation for three weeks prior to light culture in culture rooms at 25℃ tends to benefit the adventitious bud regeneration from the leaf disks.