Studies on the Tissue Cultue of Pinus taeda, P.elliottii and P.serotina

The embryos, of the mature seeds of P.taeda L., P.elliottii E., P.serotina M., were used as experimental material. The explants were placed on modified GD medium(total salt 0.21%, total nitrogen 186 mg/L) suplemented with BAP for 3～4 weeks to induce swollen dark green callus, then the buds were found on embryos, cotyledon and hypocotyl.The rate of differentiation reached 75%～85%, and the concentration of BAP played an important part in the differentiation of adventiation buds of three pines, normally 3～5 mg/L is suitable.They were subcultured to medium containing activated charcoal, which is benefical to the growth of shoots.When the shoots grown to the length of 1.5 cm, they were planted on the rooting medium with 0.5 mg/L NAA for 15～20 days, and the white callus were visible.At this point they were transferred to the hormone free medium for 15～20 days to root, when the plantlets were planted in soil, 85%～90% of them have survived.