| 摘要: |
| 荞麦属植物是栽培荞麦作物遗传改良的基因库，但该属的系统位置及物种鉴定存在争议。为探讨荞麦属花粉的形态特征及其分类学意义，通过扫描电镜观察了荞麦属11种及2亚种的花粉形态特征，结果表明：（1）13个样品的花粉形状为长球形或近球形，花粉大小在种间差异较明显，甜荞野生近缘种和细柄野荞为大粒花粉，花叶野荞属小粒花粉，其余10种均属中等花粉。（2）花粉外壁纹饰均为细网状，但种间的花粉表面网眼大小和密度存在明显差异。（3）聚类分析的结果显示：苦荞野生近缘种、线叶野荞麦、栽培苦荞麦、硬枝野荞麦和花叶野荞的花粉形态相似，萌发沟长、宽均较小，花粉形状近球形和长球形，花粉大小为中等大小或小花粉；密毛野荞、疏穗野荞麦、长柄野荞麦、灌野荞麦、金荞麦和理县野荞的花粉形态相似，具有萌发沟长、宽为中等，花粉形状为近球形或长球形，花粉均为中等大小；而甜荞野生近缘种与细柄野荞花粉形态相近，并且与其他物种差异较大，表现在网眼宽、网脊宽、网眼大小和萌发沟长、宽最大，花粉形状为长球形，花粉大小为大花粉。该研究结果表明，荞麦属植物花粉具有形状为长球形或近球形、外壁纹饰呈细网状、萌发孔为三孔沟等共同特征，明显区别于广义蓼属其他植物，可以作为该属系统地位的参考依据。花粉形态虽然存在一定种间差异，但分辨率较低不足以用于确定种的分类地位。 |
| 关键词: 荞麦属，花粉形态，花粉外壁纹饰，聚类分析，分类学 |
| DOI：10.11931/guihaia.gxzw202406029 |
| 分类号: |
| Fund project:四川省科技厅项目（2023YFN0019）；西昌学院博士启动项目（YBZ202335）；厅州共建攀西特色作物研究与利用四川省重点实验室发展基金项目（XNFZ2201，SZ21ZZ05） |
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| Pollen morphology and taxonomicsignificance of 13 taxa of Fagopyrum (Polygonaceae) |
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HU Meng1,2, TAN Lu2, WANG Qinghai2, DU Hanmei2, LI Shengchun2, XU Zhou2, WU Dandan1, WANG Anhu2*
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1. Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China; 2. Panxi Crops Research and Utilization Key Laboratory of Sichuan Proince, Xichang University, Xichang 615000, Sichuan, China
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| Abstract: |
| The genus Fagopyrum is the gene pool for the genetic improvement of cultivated buckwheat. The phylogenetic status of this genus and the biosystematic relationship of some species are still controversial. Pollen morphology of Fagopyrum was observed by scanning electron microscope to provide some clues to explore the morphological characteristics of Fagopyrum and its taxonomic significance. The results were as follows: (1) The pollen shape of the Fagopyrum species varied from subspheroidal to prolate, and the pollen sizes varied significantly among species. Of which, the pollen of F. tataricum ssp. potanini and F. gracilipes were the biggest, F. callianthum was the smallest, the rest were medium-sized. (2) The pollen exine ornamentation of Fagopyrum species was a finely reticulate. However, there are lumen differences in the size and density of pollen surface perforation among different species. (3) Cluster analysis showed the pollen morphology of F. tataricum ssp. potanini, F. lineare, F. tataricum, F. urophyllum, and F. callianthum had similar characteristics, The germination furrow is small in length and width, the pollen shape is subglobose and oblong, and the pollen size is medium or small. F. densovillosum, F.caudatum, F. statice, F. rubifolium, F. dibotrys, and F. macrocarpum were similar, with germination furrow of medium length and width, pollen shape subglobose or oblong, pollen all of medium size. Surprisingly, the pollen morphology of F. esculentum ssp. ancestralis and F. gracilipes were quite different from other species, expressed in mesh width, ridge width, mesh size and germination furrow length and width are the largest, pollen shape is oblong and pollen size is large. In all, the pollen of Fagopyrum has the common characteristics of sub-spheroidal or prolate shape, exine ornamentation is finely reticulate, tricolporate aperature, which are different from other species of Polygonum, which means that it can be used as a reference to determine the phylogenetic status of this genus. Although there are differences in pollen morphology between taxa, the low resolution is not enough to distinguish the species of Fagopyrum. |
| Key words: Fagopyrum, pollen shape, extine ornamentation, cluster analysis, taxonomic status |
