国产广义飞蛾藤属(旋花科)植物种子表面微形态及其分类学意义

首次报道用扫描电镜观察的国产广义飞蛾藤局10种1变种植物的种子表面微形态特征。该属种子表面微形态特征可分为两大类型，其中I类型又可细分为3个亚型。除模式种Porana volubilis Burm.f.外，广义飞蛾藤属的种子表面微形态特征较为一致。因此，种子表面微形态特征不支持将广义飞蛾藤属拆分为4属或5属。研究结果显示，种子表面微形态在作为属内种的分类鉴别特征具有一定价值，如种子表面微形态支持保留毛果飞蛾藤的变种等级。将种子表面微形态与该广义属的花粉形态，以及宏观形态学特征进行对比分析，结果表明，广义飞蛾藤属种子表面微形态在属下等级的划分上没有很大价值。此外，鉴于P.volubilis Burm.I.具特殊的种子表面微形态特征，该种与广义飞蛾藤属属内其余种的关系值得进一步深入研究。

Micromorphological Features of the Seed surface of Porana s.l. (Convolvulaceae) from China and Its Taxonomic Significance

Micromorphological features of seed surfaces of Porana s.l.(Convolvulaceae),inclu ding ten species and one variety,were examined under scanning electron microscope(SEM)for the first time.The result indicated that micromorphological features of seed surfaces of Porana s.l.could be divided into two types,namely the palmate venation type and the pinnate venation type,with three subtypes in the first type.To divide Porana s.l.into 4 or 5 genera is not supported by micromorphological features observed,because the rest species of Porana s.l.have similar micromorphological features except P.volubilis Burm.f..Micromorphological features of seed surfaces,pollen morphology and macromorphology were comparatively analyzed,and it was demonstrated that,although the features provided few criteria to subdivide Porana s.l.,micromorphological features of seed surfaces could be used as reliable diagnostic characters to identify species.Micromorphological features of seed surfaces do not support to raise P.racemosa Roxb.var.sericocarpa C.Y.Wu to P.truncata Kurz.In addition,due to specific micromorphological features of the type species P.volubilis Burm.f.,the relationship between it and the rest species in Porana s.l.should be studied further.