摘要： 用纸层析法和比色法分离测定了几种沙生植物叶片可溶性糖和多糖含量、日变化及失水50%时的多糖含量。结果表明：沙冬青、白刺、霸王、籽高和猫头刺白天可溶性糖最高含量分别为16%、8%、14%、11%，5%。前三种植物多糖最高含量分别为5.6%、7.6%、7.5%，其日进程与可溶性糖存在一种互补关系；叶片失水50%时，白刺多糖增加1.31倍，霸王1.21倍，沙冬青0.44倍。这表明：某些沙生植物主要靠增加可溶性糖含量以提高渗透调节能力适应干旱；有的则以增加多糖含量以增强胶体保水能力忍耐干旱；另一些植物则兼而有之。

关键词: 沙生植物, 叶片含糖状况, 忍耐干旱

Abstract: The amount of aoiuble sugar and polysaccharid contents and their daily changes and the amount of pleysccbairde whewn water less is 50% of the total in several psmmophyte leaves were measored with chonatography and the cholorimetry.The result have shoen that the maxinum contents of the soluble sugar in day time in Ammopiptanthus mongolica(Maxim)cheng f.Nitraria tangucorum,Zygophyllum xanthoxylon,Artemsia sphaerocephala and oxytropis aciphylla are respectively 16%,8%,14%,11% and 5%.In the first three Plant the maximum contents are 5.6%,7.6%,and 7.5%.Therefore,there is a mutualty conplenetary relation between daily process and soluble sugar.When water loss is 50% of the total,polysaccaride in Nitratia tangurorum increase by 1.31times,and in Zygophyllum xanthoxylon increase by 1.2 times.Ammopiptanthus mongolica(Maxim)cheng f.only increase by 0.44 times.The results indicate that some psammophytes rely on meressing soluble sugar to increase osmotic adjustment tm to endure drought conditions,while others rely on increasing polysaecharide to strengthen colloid formarion to store more water to adapt dry conditions,and some other kinds of psammophy tolerate dry conditions in both ways.

Key words: Psammophyte, Sugar contents, Drought resistance