恒温条件下采收时机对铁皮石斛多糖的影响

Effects of sampling time on polysaccharides of Dendrobium catenatum under temperature-controlled condition

为揭示铁皮石斛多糖积累的规律,明确采收时机对铁皮石斛多糖的影响,该研究在组培室恒温条件下,于2015年12月至2016年11月预培养铁皮石斛D21无性系小苗至1 cm左右,然后转接培养2~5个月后采收,用苯酚硫酸法测定多糖含量、柱前衍生-UPLC分析单糖组分的差异,结果显示多糖及其关键组分甘露糖的含量与培养月龄呈正相关,但各种培养月龄多糖含量均在5—6月份具有峰值,并与大田种植条件下的趋势吻合,表明即使在组培室恒定条件下,采收季节仍然显著影响多糖及其组分的含量,这种植物内在调控的多糖积累动态变化趋势可能与铁皮石斛固有的感知四季变化的生命节律有关。

In order to reveal the accumulation trend of polysaccharides in Dendrobium catenatum and determine the effect of sam- piing time on polysaccharides, D. Catenatum D21 clone was harvested from January to December after culturing for 2 to 5 months in the growth chamber with constant temperature. Polysaecharides were determined by phenol-sulfuric acid method and the monosaccha- ride compositions were analyzed by pre-column derivative-UPLC. The results showed that the content of polysaccharide and its key com- ponent mannose was positively correlated with the culture time, but the contents of polysaccharides in all kinds of culture peaked from 5 to 6 months, which were consistent with the trend of field planting. The results suggested that the trend of polysaccharide accumula- tion in the plant could be related to the life rhythm of the sensory seasons of D. catenatum, which was significantly affected by the har- vesting season, even under the constant condition of the culture chamber.