中国木犀属花粉形态研究及其系统学意义

Pollen Morphology of Osmanthus (Oleaceae) in China and Its Systematic Significance

摘要:

观察了中国木犀属4组21种植物的花粉形态。花粉为圆球形或近长球形,外壁表面均具网状纹饰。大多数种类都具有三孔沟的萌发孔,极少四孔沟,或六萌发孔。内孔明显或不明显,有9种植物同时存在具三孔沟和具三沟二种类型的花粉及中间过渡类型(显脉木犀同时存在具三拟孔沟和具四拟孔沟)。很多特点表明,木犀属花粉的萌发孔在木犀科中处于由简单萌发孔向复合萌发孔过渡的阶段。根据网眼从沟间区中央到沟边是否变细,可将本属花粉分为两大类型,与分组有一定的对应关系。综合一些花粉特征,可发现本属花粉形态差异较明显,与一般形态差异有一定的相关性。花粉形态在木犀属具有一定的系统学意义。

Abstract:

Morphological studies of the pollens of 21 species in four sections of genus Osmanthus from China are reported in this paper. The pollen grains are spheroidal or subprolate in shape. The sculptures of the pollen exine are unexceptionally reticulate. Most species are 3-colporate, and few are 4-colporate or with 6 apertures. The ora are obvious or not obvious. Especially, pollens of each of the nine species are 3-colpate and 3-colporate; O.hainanensis is 3 and 4-colporoidate. Transitional types of the apertur also exist in these species．Some characters indicate that the pollen aperture of genus Osrnarahus is on the transitional stage from simple to compound apertures in Oleaceae．Two types ofpollens can be divided based on whether or not the lumen become small from the center of the mesocolpium toward the colpi．Th e sculpture characters show correspondence to the sectional division of Osmanthus，and to some extents the comprehensive characters of pollen morphology have corelation with that of the structural morphology ．In general，pollen morphology presents a systematic significance in the genus Osmanthus．