【作者】 孙小芹； 舒璞； 周义锋； 郭建林； 杭悦宇；

【机构】 江苏省中科院植物研究所江苏省植物迁地保护重点实验室；

【摘要】 利用扫描电子显微镜(SEM)对中国薯蓣科薯蓣属7组34种1亚种2变种植物叶表皮的微形态进行了观察比较研究。结果表明薯蓣属植物叶表皮毛可分为3种类型:乳突、单细胞毛和多细胞毛。单细胞毛有长单毛、短单毛、二叉毛、三叉毛4种形态,多细胞毛有多细胞单列毛、多细胞头、单细胞柄腺毛2种形态。表皮毛在各组中类型多少有差异,分布频率也不同,但主脉分布频率大于叶肉,最少为二级脉,乳突在主脉形状除分散也有连成波状排列,由于乳突的不等量轮状排列曾被误认为是鳞片状毛。不分枝单毛(长短非腺毛和腺毛)在薯蓣属各组中分布具普遍性,二叉毛(V型),三叉毛,分布较少,根据原始性状普通型原则,我们初步认为在单子叶植物中单毛是原始性状。根茎组有原始的单毛,也有发展中演化的2叉(V型)毛,可以说根茎组既是发生中心又是一个分化中心,根据表皮毛类型在薯蓣属组中的分布规律来看认为该属存在着2条演化路线,一条是根茎组-复叶组-丁字毛型组-顶生翅组的长短非腺毛的演化路线,另一条是根茎组-薯蓣组-黄独组的腺毛路线。更多还原

【Abstract】 The study and analysis were carried out on the micro-morphology observation of the leaf epidermis from 7 groups of the Chinese Dioscoreaceae Dioscorea, which consisted of 34 species, 1 subspecies and 2 varieties by scanning electron microscopy (SEM). The results showed that the leaf epidermal trichome of Dioscorea L. could be classified into three types: papilla, unicellular hair and multicellular hair. Unicellular hair had four forms of long, short, binary forked and trigeminal forked, while multicellular hair included two types of multicellular uniseriate hair and glandular hairs of multicellular head and unicellular stalk. There existed differences in the types and distribution of frequency of foliar trichome in each group. Generally, the distributed frequency was greater in leaf main vein than in mesophyll, with the least frequency in the second vein. The papilla spreaded into a wavy arrangement besides dispersion in the main vein and had been mistaken for a scale-like hair due to the non-equivalent whorled arrangement. Unbranched unicellular hair (long and short of the non-glandular and glandular hairs) displayed a universal frequency of distribution in yams. And the binary forked (V-type) and trigeminal forked hairs were the less common types. According to the ordinary principle of the original characters, it ’s preliminarily proposed that unicellular hair would be the original character in monocots. The Sect. Stenophora, which had the original unicellular and the evolved binary forked (V-type) hairs, was likely to be not only the origin but also the differentiated center. According to the distributed type of foliar trichome in the Dioscorea L., it ’s elucidated that there might exist two evolutionary routes in this genus, one was the long and short non-glandular route of Sect. Stenophora-Sect. Botryosicyos-Sect. Combilium-Sect. Shannicorea, the other was the glandular route of Sect. Stenophora-Sect. Enantiophyllum-Sect Opsophyton.更多还原