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该文通过揭示铁皮石斛叶片多糖和醇溶性浸出物含量的动态变化规律,为铁皮石斛叶片资源的开发利用提供依据。采用苯酚-硫酸法和醇溶性浸出物热浸法测定铁皮石斛3个优良品系不同月份的叶片中多糖和浸出物含量。结果表明,铁皮石斛叶片多糖质量分数为4.45%~12.17%,约为茎的1/4,醇溶性浸出物质量分数为7.45%~29.34%,约为茎的1.5倍。铁皮石斛叶片多糖含量变化与物候期密切相关,冬季、萌芽初期和落叶期植株代谢水平降低,叶片多糖含量减少;植株生长旺盛期,叶片多糖含量较高。叶片中浸出物含量在萌芽前达到最高值,促进了新芽的萌动。
In this paper, the dynamic changes of polysaccharides and alcohol-soluble extracts in leaves of Dendrobium candidum were revealed to provide the basis for the exploitation and utilization of the leaves of Dendrobium officinale. The contents of polysaccharides and extracts in leaves of three elite lines of Dendrobium officinale were determined by phenol-sulfuric acid method and alcohol-soluble extract hot-dip method. The results showed that the content of polysaccharides in leaves of D. officinale was 4.45% ~ 12.17%, which was about 1/4 of the stems. The content of alcohol-soluble extracts was 7.45% -29.34%, about 1.5 times of the stems. The contents of polysaccharides in leaves of Dendrobium officinale were closely related to the phenophase, and the levels of plant metabolism decreased in winter, early budding and deciduous stages, while the content of polysaccharides in leaves decreased. In the vigorous growth stage, the content of polysaccharide in leaves was high. The content of the extract in leaves reached the highest value before germination, which promoted the germination of new shoots.