青藏高原不同海拔地7种风毛菊属植物叶片解剖结构的研究

Studies on the Anatomical Structures of Leaves of Seven Saussurea DC. Species on the Qinghai-Tibetan Plateau with Different Altitude

对青藏高原东缘海拔2100～4200m处生长的7种风毛菊属植物共29个居群的叶结构进行了显微观察,分析探讨7种植物叶解剖结构与自然环境的相互关系。结果发现:7种植物均为异面叶,表皮细胞单层,角质层厚;叶肉栅栏组织、海绵组织和叶片的总厚度均随海拔升高而增大,并普遍形成发达的通气组织。表明了7种植物的叶片既具有中生植物又兼有旱生和湿生植物的部分结构特征,这些现象说明了这些特征是这7种植物对高寒地区低氧、低温、强辐射等自然条件长期适应的结果。

Leaves of seven species of Saussurea DC. （ twenty-nine populations） from 2100 m to 4200 m altitude in the eastern of Qinghai-Tibetan were studied, the relation between the structure of leaves of seven species and their environment was discussed. We have discovered that all the leaves of species are bifacial, their epidermis were single layer and had thicker cutide; With the altitude increasing, the thickness of the leaves, palisade and spongy tissue increased, and all of them had well-developed aerenchyam. Our results indicated that leaves of seven species had the structural characters of the mesophytes with part of xerophytes and liydrophytes. All of these above showed that the characteristics of seven kinds of leaves were the results of adaptation to the stressful environment of the severe lack oxygen, cold climate and high solar radiation ect.