Plant regeneration from in vitro cultured leaves of Malus zumi
The leaves from in vitro plantlets of Malus zumi were cultured in MS medium containing 0.3 mg· L-1 NAA and different concentrations of 6-BA (1.0~6.0 mg· L-1). The results showed that the bud regeneration rate was from 6.7% to 31.8% while the root regeneration rate was from 26.7% to 28.3% when 6-BA concentration was from 1.0 to 3.0 mg· L-1. In the treatments with 4.5 and 6.0 mg· L-1 of 6-BA the bud regeneration rates were up to 80.0% and 60.0% , respectively. The bud regeneration rate of the leaves from Malus zumi plantlets sub-cultured for 60 days was obviously lower than that of the plantlet leaves sub-cultured for 30 days. The regeneration rates of the buds from both the cutting places and the whole leaf under the condition of cutting the primary vein crosswise were obviously higher than those under the condition of cutting the leaf blade beside the primary vein lengthwise without cutting the leaf edge or cutting the leaf blade beside the primary vein crosswise without or with cutting the leaf edge.