Department of Horticulture, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan.
Plant Systematics and Evolution Laboratory, Department of Plant Biotechnology, Atta ur Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) H-12, Islamabad, Pakistan.
Microsc Res Tech. 2021 Oct;84(10):2325-2336. doi: 10.1002/jemt.23787. Epub 2021 Apr 21.
Jasminum L. is the largest genus containing ~200 species found wild mostly in the tropical regions of the world. The comparative palynological study of nine Pakistani Jasminum species with SEM showed zonocolpus, trilobate, and tricolpus pollen types with simple endocolpus apertures which are plesiomorphic and conserved in the Jasminum species. The equatorial pollen view was prolate, subprolate, and perprolate with elliptic, lobate, subcircular whereas polar view was subtriangular in all species. Few characters were specific to some species like heteropolarity in Jasminum grandiflorum and foveolate exine ornamentation with rounded heterobrochate in Jasminum angulare whereas reticulate and angular homobrochate character was common in other species. The UPGMA dendrogram based on qualitative characters did not support the phylogenetic classification of the genus Jasminum as these are highly conserved. The quantitative data showed more variation in some characters whereas few characters showed little or no variation. A greater variation in pollen size was observed among the variants of same species, for example, Jasminum humile showed highly variable polar length and equatorial diameter as compared to other species. Minimum variation was observed in colpus length which divided all species in to two groups. The large lumina were specific to Jasminum nitidum and broader muri was the prominent characteristic of Jasminum angulare. Some species like Jasminum sambac and Jasminum azoricum were unable to develop true pollen due to structural or functional disabilities. So, the quantitative characters of pollen are only suitable for palynological based grouping of Jasminum species but less suitable to infer their evolutionary relationship.
素馨属（Jasminum L.）是最大的属，包含约 200 种，主要分布在世界热带地区。使用 SEM 对 9 种巴基斯坦素馨属植物的比较孢粉学研究表明，具 zonocolpus、trilobate 和 tricolpus 花粉类型，具简单的内孔，这在素馨属植物中是原始且保守的。赤道面花粉观为长球形、近长球形和超长球形，具椭圆形、瓣状、近圆形，极面观为近三角形。少数特征是某些物种特有的，如花茉莉（Jasminum grandiflorum）的异极性和 Jasminum angulare 的具圆形异槽的网纹外壁纹饰，而网状和角状同槽特征在其他物种中较为常见。基于定性特征的 UPGMA 聚类树不支持素馨属的系统发育分类，因为这些特征高度保守。定量数据显示，一些特征存在更多的变异，而少数特征变异很小或没有。同一物种的不同变种之间观察到花粉大小的更大变异，例如，Jasminum humile 的极轴长度和赤道直径比其他物种变化更大。在 colpus 长度上观察到最小的变异，这将所有物种分为两组。大的腔室是 Jasminum nitidum 的特征，较宽的壁是 Jasminum angulare 的突出特征。有些物种，如 Jasminum sambac 和 Jasminum azoricum，由于结构或功能障碍，无法发育出真正的花粉。因此，花粉的定量特征仅适用于基于孢粉学的素馨属植物分组，但不太适合推断它们的进化关系。
