Department of Plant Sciences, Faculty of Biological Sciences, Alzahra University, Tehran, Iran.
Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.
Microsc Res Tech. 2024 Dec;87(12):3073-3088. doi: 10.1002/jemt.24663. Epub 2024 Aug 15.
The pollen morphology of 33 species belonging to the genera Lactuca, Launaea, Cicerbita, Sonchus, Condrilla (tribe Cichorieae: Asteraceae) from Iran were studied with light and electron microscopies. The pollen grains of the investigated taxa are almost oblate-spherical to prolate-spherical, the shapes are circular in equatorial view, hexagonal in polar view, only Sonchus species are triangular or quadrangular in polar view, isopolar, symmetrical and trizonocolporate, except Sonchus and Chondrilla species, which have tri- to tetrazonocolporate pollen grains, and echinolophate. The size and number of spines in the polar area and the number of spines in the paraporal ridges and equatorial ridges proved to be the most taxonomically authentic characteristics in this study. Three pollen types were distinguished, as in alignment with previous studies. Cluster analysis by Ward method based on 10 quantitative morphological characteristics of pollen grains revealed that the species could be grouped based on the pollen characteristics. Moreover, three species of Cicerbita including Cicerbita scoparia (Rech. f. & Köie) Kitam, C. rechingeriana (Tuisl) Coșkunç., M. Güzel & N. Kilian and C. microcephala (DC.) M. Güzel, Coșkunç. & N. Kilian were recorded for the first time in Iran. Although the characteristics of the pollen grains were useful for distinguishing the species in sub-tribes, in some cases, this did not confirm recent phylogenetic results. The pollen characteristics described in this study provide data that may be useful for future systematic studies aiming to complete the knowledge on Cichorieae species. RESEARCH HIGHLIGHTS: In the present study, the pollen morphology of 33 species belonging to five genera of the Cichorieae are investigated with scanning electron microscopy and 12 species are analyzed for the first time. The cluster analysis based on the quantitative morphological characteristics of pollen grains revealed that the species could be grouped based on the pollen characteristics. In addition, three species of Cicerbita are reported for the first time in Iran.
利用光学显微镜和电子显微镜研究了来自伊朗的菊科莴苣族（ Lactuca 、 Launaea 、 Cicerbita 、 Sonchus 、 Condrilla ） 33 个种的花粉形态。所研究的分类群的花粉粒几乎为扁球形至长球形，在赤道面为圆形，极面为六边形，只有 Sonchus 种在极面为三角形或四边形，为等极、对称和三沟孔，除了 Sonchus 和 Chondrilla 种，它们具有三到四沟孔花粉粒和具细齿的外壁。在极区的刺的大小和数量以及副极脊和赤道脊的刺的数量被证明是本研究中最具分类学真实性的特征。根据花粉粒的 10 个定量形态特征，通过 Ward 法进行聚类分析，结果表明，基于花粉特征，这些种可以分组。此外，还记录了菊科 Cicerbita 属的三个种，包括 Cicerbita scoparia （Rech. f. & Köie） Kitam 、 C. rechingeriana （Tuisl） Coşkunç. 、 M. Güzel & N. Kilian 和 C. microcephala （DC.） M. Güzel 、 Coşkunç. & N. Kilian ，这在伊朗是首次记录。尽管花粉粒的特征可用于区分亚族中的种，但在某些情况下，这并不能证实最近的系统发育结果。本研究中描述的花粉特征为未来旨在完善菊科物种知识的系统研究提供了有用的数据。研究亮点：在本研究中，利用扫描电子显微镜研究了 5 个属的 33 种菊科植物的花粉形态，其中 12 种是首次进行分析。基于花粉粒定量形态特征的聚类分析表明，种可以根据花粉特征进行分组。此外，在伊朗首次报道了三个 Cicerbita 种。
