木通科、大血藤科花粉壁的超微结构研究

应用透射电子显微镜(TEM)观察了木通科Decaisnea,Sinofr-anchetia,Holboellia,Stauntonia属以及大血藤科Sargentodoxa属共18种植物花粉壁的超微结构。所观察的木通科和大血藤科植物具较发达的覆盖层和柱状层;外壁内层以及内壁均在萌发沟处明显增厚;基层通常不甚发达。与扫描特征相对应的覆盖层结构特征,显示出类群的特异性。在Stauntonia属,覆盖层富于形态变化,反映出该属在木通科中较进化的地位;大血藤(Sarg-entodoxa cuneata)花粉壁结构隶属木通型花粉结构,表明大血藤科与木通科的密切关系。

A STUDY ON THE ULTRASTRUCTURE OF POLLEN WALL OF LARDIZABALACEAE AND SARGENTODOXACEAE

Ultrastructure of pollen wall of 18species of Decaisnea, Sinofranche-tia, Holboellia Stauntonia (Lardizabalaceae), and Sargentodoxa (Sargentod-oxaceae) have been investigated by transmission electron microscopy(TEM). The most species examined have well developed tectum and columellae; the foot layer is generally thinner and consistent; endexine is very thin in mesocolpus but very well developed in colpus. The characteristic prominents and indentations on the surface of tectum, and the grain or column like columellae are of great taxonomic significance. In Stauntonia, the varied tectum morphology reflects the advanced taxonomical position of the genus in Lardizabalaceae. The species from Sargentodoxaceae has very lardizaba-lic pollen wall structure, thus, shows closer relationship with its sister fa-mily-Larbizabalaceae.