毛茛叶报春组一存疑种花粉形态的多样性研究

Intraspecific Variability of Pollen Morphology of A Suspicious Species in the sect. Ranunculoides

对分布于浙江西北部的毛茛叶报春组(sect.Ranunculoides)一存疑种5个居群共50个植株的花粉形态进行了研究观察。结果表明该存疑种的花粉形态特征在种下具高度多样化,根据萌发孔类型、数量及组成的不同,其花粉可划分为多沟型、沟多孔少型、孔多沟少型、散孔型和环沟型5种类型;而且居群间花粉的大小及花粉类型的组成也存在较大的差异;此外,同一个植株或同一个花粉囊的花粉也可能具有多种类型的花粉。本文进一步证明了花粉形态特征在种内可能存在多样化的现象。花粉形态特征支持该存疑种为一个独立的新物种,它很可能是由具多沟型和散孔型花粉的亲本杂交进化而来。

We investigated the pollen morphology of 50 individuals （from five populations） of a suspicious species（ in sect. Ranunculoides Chen et C. M. Hu）, distributing at northwestward in Zhejiang Province. The pollen morphology of this suspicious species were high diversity. Based on the shape and number of aperture and their component, five pollen types could be recognized, including stephanocolpate type, colpi more than pores type, pores more than colpi type, pantoporate type and ringcolpate type. The component of pollen types was comparatively different among studied populations. There might be more than one pollen types within the same individual or the same anther. There might be high variability of pollen morphology at intraspecific level. Pollen morphology characters showed this suspicious species was a distinct and authentic new species, and likely evolved from cross bred progeny of parents with stephanocolpate type and pantoporate type pollens.