@article{article_1730224, title={Assessment of the UV-B absorbing compounds’ absorbance levels in pollen grains of hazelnut genotypes}, journal={Anatolian Journal of Botany}, volume={9}, pages={176–181}, year={2025}, DOI={10.30616/ajb.1730224}, author={Kilin, Özkan and Toksöz, Orçun and Çetinbaş Genç, Aslıhan}, keywords={UV-B radiation, pollen grain, ultraviolet-absorbing compounds, sporopollenin}, abstract={Pollen grains, as highly sensitive reproductive units, rely on structural and biochemical mechanisms to withstand environmental stressors, particularly UV-B radiation. This study evaluated the UV-B absorbance capacity of UV-B absorbing compounds extracted from cytoplasmic, wall-bound, and sporopollenin-associated fractions of pollen grains from four Corylus avellana genotypes (Sarı, Palaz, Kara, Yomra). Spectral analyses revealed distinct fraction-specific absorbance patterns, showing a general decrease between 280–315 nm in the cytoplasmic and wall-bound fractions, whereas the sporopollenin fraction exhibited an increasing trend. Spectrophotometric analyses revealed that the cytoplasmic fraction exhibited the highest UV-B absorbance across all genotypes, followed by the sporopollenin and wall-bound fractions. Genotype-specific patterns were evident, with Palaz showing the highest cytoplasmic absorbance and Sarı displaying superior sporopollenin-associated absorbance, while Kara consistently recorded the lowest across all fractions. Multivariate analyses, including principal component analysis and heatmap clustering, confirmed distinct groupings among genotypes and UV-B absorbing compounds fractions. These findings suggest that inherent variability in UV-B absorbing compounds distribution contributes to differential photoprotection potential among genotypes. Identifying hazelnut genotypes with stronger inherent UV-B defense capacity may inform breeding strategies aimed at improving reproductive resilience under increasing UV-B exposure.}, number={2}, publisher={Abdullah KAYA}