五味子属植物种子形态特征及其分类学意义

Morphological Diversity of Schisandra (Schisandraceae) Seeds and Its Taxonomic Implication

在扫描电镜下观察了70多份五味子属种子样品,并拍摄了照片,其中34幅展示在文中。选取代表27个分类群,34个居群的36份种子样品,每份样品20粒,测量长、宽、厚,取平均值。采用“相对体积”这一新概念作为种子形态比较的一项指征。同时对种子整体照片所呈现的表面纹饰进行了分析归纳,将其分为4个类型:(1)平滑或基本平滑,(2)有明显的皱纹,或有或疏或密的疣状突起,(3)有密集而显著的乳头状突起,(4)密被不规则的、有结节的绳索状突起,突起物曲折蜿蜒,酷似哺乳动物的大脑。综合种子的大小、颜色、表面整体纹饰以及雄蕊群特征等分析的结果表明,少蕊组sect.Maximowiczia、五味子组sect.Schisandra和球蕊组sect.Sphaerostema的种子形态分别与其雄蕊群特征具有高度的相关性;而多蕊组sect.Pleiostema的情况稍微复杂一点,但种子形态与与其雄蕊群特征之间仍然有部分相关性。本文以种子的整体形态为基础讨论五味子属种子表面形态在该属分类上的意义。研究种子整体形态得到的证据与研究种子表面微形态得到的证据一致,不支持林祁(2000)和Saunders(2000)对五味子属的分类修订,也不支持刘玉壶(1996)将球蕊组sect.Sphaerostema划分成两个亚属的修订。

Thirty-six seed samples represented 34 population of 27 taxa of Schisandra are measured in three dimentions. One new concept of ＂relative volume＂ was adopted here. 34 photographs of the seeds are selected for discussing seed feature and taxonomic significance of Schisandra. The seed surface of Schisandra may he divided into four types： （ 1 ） smooth or subsmooth; （2） obviously rugose or sparsely or densely tuberculate; （3） with dense papillae; （4） with irregular nodular rope-like protuberance, like cerebrum of the mammal. The comparative analysis of entire features from the seeds and androecium demonstrated that a highly relative variability between seed morpha and androecium feature existed in sect. Maximowiczia, Schisandra and Sphoerostema respectively except sect. Pleiostema with a smaller degree of the relative variability. The taxonomic revisions on Schisandra contributed by Lin Qi （2000） and Saunders （2000） are not supported by the comprehensive investigation for the marpha, relative vohume, colonr and surface sculpture of the seed in the present paper. Dividing sect. Sphaerostema into two subgenera by Law yu-wu is not supported by the evidences from the seeds also.