中国薯蓣属植物地下茎淀粉粒形态特征及其分类学意义

Morphological features and its taxonomic significance of starch grain in subterranean organ of Dioscorea L. in China

对中国薯蓣属（Dioscorea L．）40个种类地下茎的淀粉粒形态进行了显微观察。结果表明，中国薯蓣属植物地下茎淀粉粒主要有单粒和复粒2种形态。单粒淀粉粒以类圆形为主，脐点多为点状。复粒淀粉粒可分为2类：A型由2～3个淀粉小粒构成，以卵圆形和三角形为主，脐点点状且大多不明显，少数种类层纹清晰；B型由10个以上的淀粉小粒构成，以圆形为主，脐点不明显，无层纹。根状茎组（Sect．Stenophora Uline）、基生翅组（Sect．Opsophyton Uline）和周生翅组（Sect．Enantiophyllum Uline）均为单粒淀粉粒；顶生翅组（Sect．Shannicorea Prain et Burkill）为复粒淀粉粒A型；丁字型毛组（Sect．Combilium Pra Jnet Burkill）和白薯莨组（Sect．Lasiophyton Uline）为复粒淀粉粒B型；复叶组[Sect．Botryosicyos（Hochst．）Uline]兼有单粒和复粒淀粉粒。淀粉粒形态特征支持白薯蓣（D．hispida Dennst．）由复叶组分出单列成组及毛芋头薯蓣（D．kamoonensis Kunth）和高山薯蓣（D．delavayi Franch．）互为独立种的分类学处理。

The morphological features of starch grain in subterranean organ of 40 species of Dioscorea L. in China were studied. There were two types of starch grain, simple grain and compound grain. Main shape of simple grain was rotundity alike, with punctuate hilum mostly. Whereas, compound grain could be classified to two types. The type A was composed of 2 -3 granules of oval and spherical shapes with punctuate and indistinct hilum mostly, except a few of type A with distinct annular striation. The type B was compounded of more than 10 granules of rotundity shape with indistinct hilum and absent annular striation. Simple grain was observed in Sect. Stenophora Uline, Sect. Opsophyton Uline and Sect. Enantiophyllum Uline and compound grain of type A in Sect. Shannicorea Prain et Burkill, while type B in Sect. Combilium Prain et Burkill and Sect. Lasiophyton Uline. Simple and compound starch grains were both found in Sect. Botryosicyos （Hochst.） Uline. The taxonomic argument that D. hispida Dennst. as a single section was separated from Sect. Botryosicyos was supported by morphological features of starch grain, and it was also suggested that D. kamoonensis Kunth and D. delavayi Franch. should be two independent species.