Makgomol Kittima, Sheffield Elizabeth
School of Biological Sciences, University of Manchester, 3.614 Stopford Building, Oxford Road, Manchester, M13 9PT, UK.
New Phytol. 2001 Jul;151(1):243-255. doi: 10.1046/j.1469-8137.2001.00160.x.
• The extent to which macro- and micromorphological features might contribute to tolerance of extremely deep shade by Trichomanes speciosum, a member of the filmy ferns (Hymenophyllaceae), is reported here. • Confocal laser scanning, transmission and scanning electron microscopy were used to study the ultrastructure of gametophytes and sporophyte leaves. • Gametophyte filament cells contain numerous small, spherical or ovoid chloroplasts, whereas sporophyte leaf cells have fewer, slightly larger, disc-shaped chloroplasts. The chloroplast grana of gametophytic cells have fewer thylakoids than sporophyte cells, although grana are not numerous in either. Gametophyte filament cell walls resemble those of sporophyte leaf cells, with two or more layers of electron-opaque material and covered in a thin cuticle. Gemma cell wall ultrastructure does not differ from that of gametophyte filament cells; rhizoid cell walls are thick and several-layered. • Neither gametophyte filaments nor sporophyte leaves have chloroplasts of the extreme forms reported for deep shade fern or angiosperm leaves. The success of the fern is attributed to a low metabolic rate and inability of other species to cope with extreme low light.
• 本文报道了膜蕨科（Hymenophyllaceae）成员美丽膜蕨（Trichomanes speciosum）的宏观和微观形态特征对其在极深荫蔽环境下耐受性的贡献程度。
• 利用共聚焦激光扫描、透射和扫描电子显微镜研究了配子体和孢子体叶片的超微结构。
• 配子体丝状体细胞含有许多小的、球形或卵形叶绿体，而孢子体叶片细胞中的叶绿体较少，稍大，呈盘状。配子体细胞的叶绿体基粒类囊体比孢子体细胞少，尽管两者的基粒都不多。配子体丝状体细胞壁与孢子体叶片细胞壁相似，有两层或更多层电子不透明物质，并覆盖着一层薄角质层。珠芽细胞壁超微结构与配子体丝状体细胞无异；假根细胞壁厚且多层。
• 配子体丝状体和孢子体叶片都没有深荫蔽蕨类或被子植物叶片中报道的那种极端形式的叶绿体。这种蕨类植物的成功归因于其低代谢率以及其他物种无法应对极低光照。
