The pollen morphology and exine ornamentation of an important autochthon plum cultivar (Prunus
domestica cv. Poˇzegaˇca L.), which has horticultural, medicinal and alimentary uses, was examined in
detail using both light and scanning electron microscope (SEM). Acetocarmine and fluorescein diacetate
were used to assess the pollen viability of four Poˇzegaˇca plum genotypes. Pollen viability varied from 67%
in genotype Pdp1 to 99% in genotype Pdp4. Also, pollen nucleus status was determined, and binucleate
mature pollens were detected. The effect of polyethylene glycol-PEG (10, 15 and 20%, w/v) on pollen
germination and tube growth was evaluated. Overall, the inclusion of PEG in the medium improved both
pollen germination and tube growth. Regardless of the PEG concentration genotype has an effect on
germination and length of pollen tubes. Genotype has a pronounced effect on germination and length
of pollen tubes, regardless of the PEG concentration used. Genotype Pdp4 had the highest germination
percentage and the highest pollen tube length on all media when compared to the other three genotypes.
The highest pollen germination (96%) and a tube length (822 m) of genotype PdP4 was attained in media
with 20% PEG.