伞形科藁本属20种植物的果实特征及其分类学意义

采用扫描电镜方法对中国藁本属20种及山芎属1种植物的果实表面微形态进行首次研究,并对其中15种进行果实解剖特征观察。结果表明:藁本属植物果实微形态在外果皮表面突起度、细胞轮廓、表面纹饰和表皮分泌物上表现出丰富的多样性;在果实解剖特征上,果棱形状、油管数目、胚乳形状等种间差异明显且稳定,而种内居群间无变异,可作为藁本属种间鉴定及种间关系探讨的重要参考性状。结合前人对伞形科其他类群果实微形态与解剖结构特征的研究及近年来分子系统学的证据,得出如下结论:(1)藁本属不是一个自然类群;(2)支持拟藁本属归入藁本属;(3)对藁本属部分种的系统位置和种间亲缘关系进行了讨论。

Fruit Features of Twenty Species of Ligusticum (Apiaceae) and Their Taxonomic Significance

The micromorphological features of pericarp surface (MFPS) in 20 species of Ligusticum and 1 species of Conioselinum in China were observed under SEM for the first time,and the transection anatomical characteristics of mericarps of 15 species of which were also studied in this paper.The result shows that MFPS,such as the smoothness and the visibility of epicarp cell,the types of ornamentation and epidermal secretions,exhibit rich diversity.The number of vittaes,the shape of ribs and endosperms were markedly different,which were evaluated as the significant references for inter-species identification and relationship discussed.From previous micromorphological,anatomical and molecular studies on Apiaceae,we concluded that:(1)Ligusticum was an artificial genus.(2) According to the MFPS and fruit anatomical characteristics,the results do not support Ligusticopsis as a natural genus.(3) In this paper,the taxonomic status and genetic relationships of some Ligusticum species were investigated.