铁皮石斛快速繁殖和离体种质保存的研究

对铁皮石斛种子发芽、原球茎增殖、丛芽分化和壮苗培育进行了试验、观察和分析,研究了培养基、植物激素、光强和添加剂等对其分化和生长的影响。结果显示种子在1/2MS+蔗糖2%的培养基上,30d萌发95%以上。原球茎在1/2MS+椰子汁25%+蔗糖3%的培养基上,45~60d原球茎增殖速度可达1∶10。丛芽分化较适宜的培养基为1/2MS+BA2mg·L-1+NAA0.2mg·L-1+IBA0.1mg·L-1+蔗糖3%,45~60d芽丛增殖速度为1∶4~5。试管苗在MS+香蕉泥20%+蔗糖2%培养基上,大约60d苗快速长高,茎粗壮且根系发达。离体保存材料可采用试管丛芽和原球茎两种方式,以保持其遗传多样性。保存方法是在15℃左右条件下,保存离体材料,继代间隔期为12~18个月;也可以采用室温保存,在1/2MS+蔗糖1%培养基上,继代间隔期可延长至10~12个月。

Studies on the rapid propagation and in vitro storage of Dendrobium candidum

The seed germination,protocorm multiplication (PLBS),differentiation of cluster buds and production of intact vigorous plants of Dendrobium candidum were examined,observed and analyzed. The impacts of basic medium,different exogenous hormones,light intensities,and complex complements on the induction and growth of multiple shoots were studied respectively. The results obtained from the present study were as follows:(1)The seed germination rate was about 95% on 1/2 MS+S 2% in 30 d;(2)The proliferation rate of PLBS could be 1∶10 in 1/2 MS+CM 25%+S 3% in 45～60 d;(3)It was the ideal medium for cluster shoot formation in 1/2 MS+BA2+NAA 0.2+IBA 0.1. The proliferation speed reached to 1∶4～5 per 45～60 d;(4)The plantlets transferred in MS+banana puree 20%+S 2% to help the production of vigorous plant,could be about 5 cm high in 60 d. The cluster buds and PLBS were used as materials for in vitro storage. Their genetic diversity could be maintained. The slow growth method to culture shoot tips or PLBS under room temperature condition and 1/2 MS+S 1%,could reduce the subculture generation and be extended to 10～12 months. The Dendrobium candidum was stored under the temperature of 15 ℃ and its growth cycle could be as long as 12～18 months for one generation.