唐古特白刺叶片形态与营养物质含量的地域采样点差异

掌握唐古特白刺叶片形态及营养物质含量的地域分异规律，有利于白刺资源的保护及利用。为探讨白刺叶片形态与营养物质含量在地域、采样点间的差异，选择荒漠化草原（乌拉特中旗）、草原化荒漠（磴口）、典型荒漠（民勤）不同采样点分布的唐古特白刺为对象，测定叶片的长度、宽度、长宽比、厚度，以及叶片中粗蛋白、粗脂肪、可溶性糖、还原性糖、粗灰分、粗纤维6种物质的含量。结果表明，白刺叶片形态对环境变化响应敏感，不同地域、生境间差异明显。不同地域相同生境的白刺叶片中粗蛋白与可溶性糖含量存在显著性差异。干旱指数低的区域，白刺长势良好，叶片增长、增厚，营养物质含量高；生长地土壤具明显盐渍化现象时，叶面积减小、长度缩短、厚度增加，可利用的营养物质含量降低，灰分和粗纤维含量增高。

Regional Differences in Morphological Characters and Nutrient Contents in the Leaves of Nitraria tangutorum

Nitraria tangutorum is one of the dominant species occurring in arid and semi-arid regions of China.It is beneficial to the conservation and utilization of N.tangutorum resources to master its regional variations of leaf morphology and nutrient contents.In order to explore the differences in leaf morphology and nutrient content among geographical regions and habitats,samples of N.tangutorum were collected from different habitats of desertification steppe(Wulatezhong County),steppe desert(Dengkou)and typical desert(Minqin).The length,width,ratio of length to width and thickness of the leaves and the contents of crude protein,crude fat,soluble sugar,reducing sugar,crude ash and crude fiber in the leaves were determined.The results showed that the leaf morphology of N.tangutorum was sensitive to environmental changes and had obvious differences among different geographical regions and habitats.Significant differences were found in the contents of crude proteins and soluble sugar in the leaves collected from different locations with similar habitats.In the regions with low drought index,the plants of N.tangutorum grew well with long and thick leaves and rich in nutrients.While in the regions with significant salinization,the leaf area and length decreased,and the thickness increased,and the leaf available nutrients decreased,the contents of leaf ash and crude fiber increased.