南五味子属(五味子科)的种子形态及其分类学意义

Seed morphology of Kadsura Juss.(Schisandraceae) in relation to its taxonomic significance

在光学显微镜和扫描电镜下对南五味子属Kadsura 1 1种植物 36个样品的种子宏观形态及种皮微形态特征进行了研究。结果表明其种子形状为肾形、椭球形、心形或肾状扁球形。在扫描电镜下种子表面特征有种间差异 ,其纹饰可分为 3种类型 ,即近平滑型、负网纹型和网纹型。短梗南五味子K .borneensis和披针叶南五味子K .lanceolata为近平滑型 ,其种子表面近平滑 ;黑老虎K .coccinea和柄果南五味子K .verrucosa为负网纹型 ,其种子表面具负网纹 ,网眼凸起 ,网脊凹陷 ;异形南五味子K .hetero clita、毛南五味子K .induta、南五味子K .japonica、冷饭藤K .oblongifolia、狭叶南五味子K .angustifolia、南洋南五味子K .scandens和大叶南五味子K .marmorata为网纹型 ,其种子表面具网纹 ,网眼凹陷 ,网脊凸起 ,此类型在南五味子属中最为普遍。种皮微形态特征在种内相当稳定 ,在一些种的划分上具有较重要的意义。南五味子属种皮微形态特征的研究结果支持将多子南五味子K .polysperma和凤庆南五味子K .interior归并入异形南五味子以及将长梗南五味子K .longipedunculata归并入南五味子的分类学处理。本文还对南五味子属植物种皮微形态的各种类型的演化趋势作了讨论。

Seed macromorphology and seed_coat micromorphology of 11 species of Kadsura (Schisandraceae) represented by 36 samples were observed under light microscope (LM) and scanning electron microscope (SEM). The seeds are reniform, ellipsoid, cordiform or reniform_oblate in shape. Under SEM the surface pattern of the seeds shows some variation among the species and three types have been observed, i.e. (1) Nearly Smooth, (2) Areolate and (3) Reticulate. In the type 1, the seed surface is nearly smooth. This type was found to occur in two species, viz. K. borneensis and K. lanceolata. In the type 2, the seed surface is areolate with prominent lumina and sunken muri. This type was found to occur in K. coccinea and K. verrucosa. In the type 3, the seed surface is reticulate with sunken lumina and prominent muri. This type is the commonest in the genus, occurring in seven species, viz. K. heteroclita, K. induta, K. japonica, K. oblongifolia, K. angustifolia, K. scandens and K. marmorata. Seed_coat micromorphological features seem to be quite constant within species and thus are of significant value in the delimitation of some species. Evidence from seed_coat micromorphological features supports the treatment of reducing K. polysperma and K. interior to K. heteroclita and of reducing K. longipedunculata to K. japonica. Brief speculation on the evolutionary trend of the seed_coat micromorphological features in the genus Kadsura is discussed.