新疆不同生境下的22种藓类植物茎和叶的比较解剖学观察

Anatomical Comparison of the Stems and Leaves of 22 Species of Mosses in Different Habitats in Xinjiang

文章使用徒手切片法对采自新疆不同生境下的22种藓类植物茎和叶片进行横切,对横切面进行比较解剖学观察和分析。结果表明大部分旱生藓类植物叶片细胞壁加厚从而减小水分的丢失,中肋由厚壁细胞和大型主细胞组成,分别起着减小水分的蒸发和导水的作用,但是这种结构不是绝对的,茎表皮1-2层细胞,皮部有内外分化,也有不分化。生长在荫湿环境下的藓类植物叶细胞壁厚,中肋很细,可能与长期生活在水分不足的环境有关,但毛尖金灰藓(Pylaisia steerei)没有中肋,中肋的退化可能与其生活在容易获取水分环境有关,茎表皮1层细胞,皮部具有内外分化。大部分水生藓类植物叶细胞壁薄,茎表皮1层细胞,皮部无内外分化,都是大型薄壁细胞,提高了细胞代谢。茎横切面形状很可能与叶片的着生和排列密切有关。

Through cross section of the stems and leaves done by hand ,observing and studying the stems and leaves of 22 species of mosses in different water conditions ,the results showed that the cell wall of mosses’ leaf which were collected from dry condition is very thick ,and reduce the loss of water .Costa was composed from thick wall cells and large main cells ,Their role is that reduce the evaporation of water and guide water respectively .But this structure is not absolutely .Epidermic cell is 1~2 layers ,have a dif-ferentiation of inside and outside of cortex or no differentiation .The mosses that growing in shady and moist condition is different from dry condition ,and itscell wall of leaf is thick ,the costa is thin ,possibly related to the condition .But Pylaisia steerei have no costa .It is possibly that the costa’ s degradation is related to the environment with easy access to water .The epidermic cell is one layers ,have a differentia-tion of inside and outside of cortex .In the aquatic environment cell wall of mosses’leaf is flimsy ,the epi-dermis cell is one layers ,and have no differentiation of cortex ,w hich is mostly composed of large paren-chyma cells ,it can improve the cell metabolism .Whatever living condition ,the cross-sections of stem shape is closely related to the growing and arrangement of leaves .