培养基渗透压对铁皮石斛原球茎生长和多糖含量的影响

Effect of Osmotic Pressureon Growth and Polysaccharide Accumulation of Dendrobium Candidum Protocorms on Culture Medium

以无菌铁皮石斛原球茎为材料,于培养液中分别添加不同浓度的甘露醇以调节其渗透压,研究不同甘露醇浓度对铁皮石斛原球茎生长及多糖含量的影响。结果表明:添加低浓度的甘露醇可促进铁皮石斛原球茎生长及增加多糖含量,添加高浓度的甘露醇能明显抑制铁皮石斛原球茎生长及降低多糖含量。在不同的培养时间,当甘露醇质量浓度为0~20g·L^(-1)时,原球茎活力、生长量、多糖含量和多糖产量总体呈上升趋势,当甘露醇质量浓度超过20g·L^(-1),原球茎活力、生长量、多糖含量和多糖产量呈下降趋势。培养后35d,各处理的原球茎干重、多糖含量和多糖产量均达最大值,且甘露醇质量浓度为20g·L^(-1)的处理其干重、多糖含量和多糖产量均高于对照和其他处理,分别为17.30g·L^(-1)、361.52mg·g^(-1)和6 255.38mg·L^(-1)。

Effect of osmosis onthe growth of and polysaccharide accumulation in theprotocorms of Dendrobium candidum on a culture medium were studied.The liquid medium wasadded with mannitolat varied concentrations to alter theosmotic pressure for the experiment.The results showed that,at low concentrations of mannitol,the growth andpolysaccharide synthesis ofthe protocorms were enhanced,but significantly inhibited at high concentrations. During the cultivation, the vigor, growth, polysaccharidecontent, andyield of the protocormsincreased when the mannitol concentration in the medium was 0-20g·L-1.After35 dculturein the medium with 20g·L^-1 mannitol,the dry weight,polysaccharide content,andyield ofthe protocormspeaked with the maximized values of 17.30g·L^-1,361.52mg·g^-1,and 6 255.38mg·L^-1,respectively.However,when the mannitol concentration was raised to 30-40g·L^-1,all of those indices hit a downward trend suggesting the high osmotic pressure could be detrimental to theprotocorm cultivation.