Tissue Culture of Stem Segments and Plantlet Regenation of Liquidambar styraciflua

The results obtained showed that browning rate of explants from stem segments with bud scale of seedlings of American sweetgum (Liquidambar styraciflua) collected in April was lower,then it gradually raised after April.Inducing rate of explants callus in April and May were quicker than that in June to Oct.Controlling effects of oxidative browning on WPM medium supplemented with different antioxidant are as follows:ascorbic acid (5 mg·L-1)mercapto ethanol (10 ml·L-1)polyvinylpyrrolidone (PVP,1 g·L-1)active charcoal (1 g·L-1).Oxidative browning rates changed from 27.5% (CK) into 2.5%,15%,20% and 20%,respectively.Inducing rate of calli and adventitious buds on WPM medium supplemented BA (6-Bbenzyl aminopurine) and Kinetin(KT) was higher than that without KT in the medium.A large number of calluses and more adventitious bud of Explants on WPM medium containing 1 mg·L-1 BA,0.5 mg·L-1 KT,0.2 mg·L-1,0.2 mg·L-1 IBA and 5 mg·L-1 ascorbic acid could induce not only a large number of callu (inducing rate:92%) but also more adventitious buds.The medium supplemented with 1 mg·L-1 indole-3-acetic acid (IAA) favored the forming of clumping shoots.Plantlets rooted well on 1/2 MS medium containing 0.2 mg·L-1 naphthalene acetic acid (NAA), 0.3 mg·L-1 indole butyric acid (IBA), and 5 g·L-1 active charcoal.The rooting ratio was 75%.