高寒冰缘区15种藓类植物茎的形态结构研究

Morphological Studies on Stem of Fifteen Species of Bryophytes from Alpine Periglacial Region

采用石蜡切片方法和扫描电镜方法,对高寒冰缘区生长的15种藓类植物茎的结构进行解剖学观察分析,为高寒冰缘区藓类植物在极端环境下的生存机理及其生态应用提供依据。结果表明:高寒冰缘区的15种藓类植物的茎分为表皮、皮部、中轴三部分。茎表皮细胞多为一层,长短不一,细胞壁表面粗糙,表面纹饰多为鳞片状、颗粒状、浅窝点状,表皮细胞的细胞壁加厚程度不同;皮部所占面积最大,大部分有内、外皮部的分化,细胞壁由外向内逐渐变薄,细胞由小到大又到小的整齐或镶嵌排列;中轴分化但其细胞数多少不一,细胞壁多具角隅加厚。研究认为,高寒冰缘区藓类植物具有典型的耐寒、耐旱结构特征,这些结构特征能够增强藓类植物的支撑和传导水分的作用,以抵御长期寒冷、干旱、多强风等恶劣环境;其中细胞的形状、数目、细胞表面的纹饰等微形态结构特征也具有潜在的分类学意义。

We observed the stem anatomic structure of fifteen species of bryophytes from alpine periglacial region by paraffin section method and scanning electron microscope(SEM),to provide basis for the survival mechanism and ecological application of mosses in extreme periglacial environment.The results showed that fifteen species of bryophytes from alpine periglacial region stems of these bryum were constituted with three parts:epidermal,cortex and central axis.The stem of most species has a cellular layer with different length epidemic cell,the cell wall is rough and thick with flaky or granular cuticle ornamentation on surface,more shrinkage depression.When the weather was dry the cuticle layer wrinkled,the different levels of depression,small pores on the depression.Cell wall thickness of adjacent cells,and some kinds of cell wall is not thickened.Cortex is the largest part,cell wall was thinned gradually from outside to inside,cells were arranged neatly or mosaic,thinned gradually from outside to inside and become fat,axis cells occupied small area,the cell wall corner is thickened.The structure characteristics of these moss plants can rapid absorption of water and resistant long term extreme arid and cold environment.The study shows that the typical characteristic of bryophytes from alpine periglacial region with strong cold resistance and drought tolerance.These structural features can enhance the support and conduction of water in bryophytes.For example,the micromorphological structure of cells shape,cell number and depression degree of cell wall,cuticle ornamentation,and small pore etc.Morphological characteristics of microstructure are meaning for classification.