Subjects: Biology >> Botany >> Applied botany submitted time 2020-05-28 Cooperative journals: 《广西植物》
Abstract： Epimedium myrianthum having much in common with E. sagittatum. There are transitions in many morphological characters and even in key taxonomy features. In order to explore the taxonomic relationship between the two taxa, the pollen morphology and ornamentation of exine of 13 populations of E. sagittatum (including 1 population of E. sagittatum var. glabratum T. S. Ying) and 7 populations of E. myrianthum were observed and compared by scanning electron microscope (SEM). The results showed that the pollen of both taxa was subspheroidal, with three-hole groove. Pollen size of E. sagittatum and E. myrianthum was (18.21-21.66) μm × (19.55-23.63) μm and (18.32-21.43) μm × (19.73-23.48) μm, respectively. The ornamentation of exine was an important character of pollen morphology. There were significant differences in ornamentation of exine among populations, which have been divided into three categories, namely reticulate, article reticulate and granular, and then divided into six subcategories according to the type of mesh ridge and mesh density. Among them, pollen morphology of E. sagittatum (including E. sagittatum var. glabratum) contained all three categories and six subcategories, and that of E. myrianthum contained three categories and four subcategories. This means that the pollen morphological variation pattern of E. myrianthum was a subset of E. sagittatum. On the whole, the variation pattern of the ornamentation of exine showed a trend, from reticulate to article reticulate, with the increase of latitude. And the main morphological characters of pollen were closely related to the elevation. As far as the pollen morphology concerned, the variation pattern of E. myrianthum was within the variation range of E. sagittatum, which was consistent with the variation patterns of other morphological characters. Pollen morphological characters could not distinguish the two taxa effectively, which failed to provide strong support for E. myrianthum as an independent species. It is suggested that the pollen morphological evidence is of relatively limited in clarifying the phylogenetic relationship among related taxa. However, further studies are still needed to provide strong evidence for the definition of large branches of phylogenetic trees of this genus.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-01-12 Cooperative journals: 《广西植物》
Abstract：淫羊藿是我国特有且传统的重要药用植物，逐渐步入大宗品种行列。物种的准确鉴定是药效保障和用药安全的前提。为促进资源合理开发和利用，对淫羊藿属分类学研究进行系统梳理，并对其中存在的问题及存疑类群进行阐述。淫羊藿属共发表68 种，中国58种（85.3%），其中57 种为特有分布，具显著资源优势。淫羊藿属中国类群的分类学研究较为特殊，共26 种集中发表于1990 s，共31 种（53.4%）为国外研究者命名，且绝大多数依据于少量栽培个体命名。缺乏广泛的形态调查和性状变异分析，导致大量类群的形态描述不准确或不全面，后续20 个类群被归并或降级。依据栽培个体命名的类群是补充描述和分类修订的重点。花色、根茎类型、花茎叶的数量及着生方式等性状在中国类群中存在广泛变异。经分类修订后，该属目前包括46 种、1 亚种和2 变种。淫羊藿属中国组类群仍处于活跃进化中，其形态变异复杂，种间关系无法得到解决，为该属分类的最大挑战。但种质资源的研究和利用需建立在清晰的分类学基础上。未来研究首先要基于居群调查，完善各物种的形态描述。在此基础上，整合形态变异特征、地理分布格局和基因序列特征，检测自然种间杂交事件，揭示物种的分化和进化历程。
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