Research Information System
Plants, vol.15, no.6, pp.1-14, 2026 (Peer-Reviewed Journal)
Abstract
Morphological characteristics of pollen grains, including shape, size, pore number, and exine
thickness, vary significantly among species and enable the reliable use of palynological
data in taxonomic studies. In this context, the present study investigates the pollen morphology
of seven Betulaceae taxa (Alnus glutinosa, Betula pendula, Carpinus betulus, Carpinus
orientalis, Corylus avellana, Corylus colurna, and Ostrya carpinifolia). Detailed morphometric
measurements were carried out using Light Microscopy (LM), and high-resolution images
were obtained using Scanning Electron Microscopy (SEM). For each taxon, thirty measurements
were taken for the main pollen characters, including polar axis length (P), equatorial
diameter (E), pore length (plg), pore width (plt), and exine thickness (Ex). Interspecific
differences were evaluated using one-way ANOVA, Tukey’s HSD test, and Principal Component
Analysis (PCA), and a diagnostic pollen identification key was developed for the
investigated species. The results demonstrate statistically significant interspecific variation
in pollen size, pore characteristics, and exine thickness. In the PCA ordination, the first principal
component (PC1) was mainly associated with pollen size (P and E), clearly separating
Carpinus betulus from the remaining taxa. The second principal component (PC2) was primarily
related to pore length (plg) and contributed to the separation of Alnus glutinosa from
the other small-pollen species. These results show that quantitative pollen morphological
characters provide reliable criteria for distinguishing closely related Betulaceae taxa.