星状雪兔子植物叶的解剖结构对高山环境的适应性

Adaptation of anatomical structures of the leaves of Saussurea stella Maxim to the alpine environment

关键词:  青藏高原  星状雪兔子  叶  解剖结构  适应性

Key words:  Qinghai Tibetan Plateau  S.stella Maxim.  leaves  anatomical structure  adaptability

摘要:

对青藏高原东缘两个不同居群的星状雪兔子植物叶的结构进行了显微观察，观察结果表明：两种不同居群植物的叶片类型均为等面叶，表皮细胞单层，角质层厚，表皮细胞形状为多边形，垂周壁平直或弓形。生于海拔2 850 m处的星状雪兔子植物，叶片厚度为330.66 μm，上表皮气孔密度为106.75，下表皮气孔密度为144.79；海拔2 890 m处的星状雪兔子植物，叶片厚度为537.07 μm，上表皮气孔密度为53.6，下表皮气孔密度为77.30。两种植物叶片类型虽然均为等面叶，但明显表现为两种不同的生态类型，这表明了星状雪兔子植物的叶在无表皮毛保护的情况下对高山环境的适应性并不是单一的。

Abstract:

The anatomical structures of the leaves of Saussurea stella Maxim in two different populations in Estern Qinghai Tibet Plateau were microscopically observed in this study. The results showed that the leaf types of S.stella in both populations were isolateral，the epidermis were single layer，and the cutide were thicker. The epidermal cells were multiangular，and the anticlinal wall were straight and arched. The leaf thickness of S.stella at altitude 2 850 m was 330.66 μm，stoma density of upper and lower epiderm were 106.75 and 144.79，while in 2 890 m altitude，the leaf thickness was 537.07 μm，stoma density of1upper and lower epiderms were 53.6 and 77.30 respectively. The result indicated that the leaves of S.stella Maxim showed two different ecological types obviously although they both were isolateral leaves，which indicated that the adaptation of the leaves of S.stella Maxim to alpine environment was not single without the protection of epidermal hair.