9种日本当归属植物的果实形态特征研究

当归属是伞形科的代表性大属,日本列岛是其重要的分布地和多样性中心之一。该研究对产自日本的9种当归属植物(特有种8种)的果实形态结构和表面微形态特征进行了观察和比较,以明确它们的分类学特征,探讨潜在的种间关系,为进一步的分类修订和系统发育研究提供资料和依据。结果表明:(1)体式显微镜观察发现,产自日本的9种当归属植物的果实形状主要为倒卵形和长圆形,表面光滑或少毛,呈不同程度的背腹压扁,背棱大多呈线状突起或狭翅状,侧棱则呈或宽或窄的翅状,油管一般为每个棱槽1条、合生面2～4条。(2)扫描电镜观察发现,大多数材料的果实具有疏密不等的平行线形初级蜡质纹饰,次级纹饰呈现鳞状、束状、索状、丘状或不明显,个别可见珊瑚状或网格状基底,一般具有颗粒状附属物。(3)通过分析比较上述形态特征和鉴别要点,编制了分种检索表,并结合中国当归属系统发育的研究成果,进一步对日本特有当归属植物的系统位置及其与东亚大陆物种的亲缘关系进行了讨论。研究认为,日本特有当归属植物的果实形态特征较丰富,能为种间分类和亲缘关系研究提供有力支持。

Morphological Analysis on the Fruits of Nine Angelica Species of Japan

Angelica L. acts as a significant representative of the family Apiaceae, of which the Japanese Islands is usually regarded as one of the important distribution areas and the diversity centers. In this study, we observed the fruits of 9 Angelica species (including 8 endemic species) from Japan in morphology, anatomy and micro morphology, respectively, in order to ascertain their taxonomical features and explore their potential relationships, and to provide more morphological evidence for taxonomical revisions and phylogenetic research. (1) The analyses of observations using stereomicroscope revealed that: the fruits usually obovate and oblong in shape, glabrous or a little pubescent on surface, dorsal compressed variously, dorsal ribs filiform or narrow winged, lateral ribs narrow or wide winged, vittae 1 in each furrow and 2-4 in commissure. (2) The result of SEM suggested that: most species had parallel filiform primary ornamentations and squamous, bunchy, cord like, hummocky or unobvious secondary ornamentations, some contained coralloid or radicular background, and appendages were granular generally. (3) Based on the above morphological characteristics and distinguishing features, the classification key for those Japanese Angelica species was organized, and combined with the results of systematic studies on the Chinese Angelica, it was also proposed the potential phylogenetic position of Japanese endemic species and the relationships with their relatives in East Asian mainland. Totally, the endemic Angelica species of Japan presented abundance of fruit features in morphology, probably providing strong evidence for their interspecies classification and relationships.