苞叶雪莲叶片的解剖特征及其生态适应性

Anatomical Characters of Leaves of Saussurea obvallata and Its Ecological Adaptabilities

[目的]分析叶片解剖结构与自然环境的相互关系。[方法]采用石蜡切片法,对分布于青藏高原东北部达坂山地区(海拔4 000m)的苞叶雪莲叶片解剖结构进行研究。[结果]苞叶雪莲为异面叶;角质层较厚;表皮细胞为单层,上下表皮都有气孔分布,气孔不下陷;栅栏组织较发达,通常由2～3层细胞组成;海绵组织存在大量的细胞间隙。[结论]这些特征是高山地区各种生态因子长期胁迫的结果,是苞叶雪莲对特殊生态环境的一种适应。

[Objective] The research aimed to study the relationship between the leaf anatomical structure and their environment.[Method] Paraffin section was adopted to study the anatomical structures of leaves of Saussurea obvallata growing in Daban Mountain（elevation 4 000 m） in the northeast of Qinghai-Tibet Plateau.[Result] This plant species was bifacial leaf.The cells of epidermis were in one layer and the cuticle was thick.The leaves had their stoma in both leaf surfaces and the stomata weren’t sunken.Palisade tissue was well developed and made up by 2-3 layers,and there was quite large intercellular spaces among sponge tissue.[Conclusion] All of the characteristics described above resulted from long-term stresses of extremely ecological conditions,such as high irradiance,cold temperature,low air pressure in Qinghai-Tibet Plateau,and were the adaptations of the plants to the alpine environments.