中国刺子莞(Rhynchospora Vahl)、砖子苗(Mariscus Gaertn.)二属果皮微形态特征的扫描电镜研究

A SEM Study on the Microstructural Features of Nutlet Surfaces to Rhynchospora Vahl and Mariscus Gaertn in China (Cyperaceae)

本文首次运用扫描电子显微镜对国产刺子莞属5个种和砖子苗属6个种的果实形态、表皮纹饰进行系统观察和比较研究。观察结果表明:根据果皮微形态特征的不同,可分为五种类型:(1)瘤(疣)状纹饰;(2)片状纹饰;(3)脊状纹饰;(4)条状纹饰;(5)瘤网状混合纹饰。刺子莞属与砖子苗属在果实形态及表皮纹饰上各具有相对一致和稳定的特征,是两个较为自然的分类群,属内不同类群之间,在果皮微形态特征上具有明显的种间差异,可为种的划分提供依据,亦可为属的系统演化与亲缘关系的研究提供有用的资料。

The present paper describe the microstructural features of nutlet surfaces of 5 species of the Rhynchospora and 6 species of the Mariscus in China. Were all examined under stereo microscope and scanning electron microsecope for the first time. According to our observation under SEM. (1) Rhynchospora differs greatly from the Mariscus not only external morphology but also in the microstructural features of nutlet surfaces. The research also proved that the Rhynchospora and Mariscus are to entirely independent and natural genus. (2) Their overall shape are ellipsoidal, broad ellipsoidal, trigonous, long round, obovoid, long obovoid, shuttleshaped. The surface ornamentation may teen divided into five types: tuberculate (verrucate), ridgeshaped, striate, pieceshaped, and verrucate-reticulate. The result has shown clearly that the fruits of Rhynchospora and Mariscus exhibit a diversity. The shape and ornamentation of the fruit have some significance for the delimitation of species.