古尔班通古特沙漠生物结皮中藓类植物形态解剖特征

对组成古尔班通古特沙漠生物土壤结皮的4种1变种藓类植物刺叶墙藓(Tortula desertorum Broth.)、真藓(Bryum argenteum Hedw.)、绿色流苏藓〔Crossidium squamiferum(Viv.)Jur.〕、泛生墙藓(Tortula muralis Hedw.)、泛生墙藓无芒变种(Tortula muralis var. aestiva Brid. ex Hedw.)的茎、叶形态解剖结构进行了观察。结果表明:除刺叶墙藓叶片上部为2层细胞组成外,其他4种叶片均由1层细胞组成。所有藓类植物叶片都具有明显或粗壮的中肋,起到了支持叶片和导水的作用。茎皮部外层细胞壁不同程度加厚。生物结皮中的藓类植物表现出叶片背卷或内卷、具疣状突起、透明毛尖(泛生墙藓无芒变种除外)以及边缘细胞壁加厚等特征,这些特征是对干旱荒漠环境长期适应的结果。研究结果为进一步揭示荒漠藓类植物形态特征与环境之间的关系提供理论依据。

Study on the Morphological and Anatomical Structures of Desert Mosses in Biotic Crust in the Gurbantonggut Desert

Some mosses composing desert biotic crust are able to survive in arid and semiarid areas because of their strong drought tolerance.Under drought stress,the moss species have developed some morphological and anatomical characteristics to adapt arid environment.There are four moss species and one variety in biotic crust in the Gurbantonggut Desert,including Tortula desertorum Broth.,Tortula muralis Hedw.,Tortula muralis var.aestiva Brid.ex Hedw.and Crossidium squamiferum(Viv.) Jur.of Pottiaceace and Bryum argenteum Hedw.of Bryaceae.In this study,the morphological and anatomical structures of these desert mosses are observed and analyzed.The results show that the upper leaves of Tortula desertorum are composed of two-layer cells,and that of other four mosses are composed of single-layer cells.All the mosses have the distinct midribs and obvious incrassation of external cortex.Some characteristics of morphological structure,such as the leaf outcurve or concave,papillose features, white hairs(except Tortula muralis var.aestiva Brid.ex Hedw.) and thick wall of marginal cells,are the long-term adaptation of the mosses to the desert environment.The study results can be referred as theoretical basis for further revealing the relationships between the morphological structure of the desert mosses and the environment.