Pollen morphology, viability, and germination of Prunus domestica cv. Požegača

• The techniques of cell biology have new implications for plant reproductive success.
• This success can be estimated using measurements of pollen quality, pollen germination and tube growth and pollen viability.
• The complex array of interrelated processes constituting reproductive success is a focus for plant biologists who need to understand, modify and exploit them for plant improvement.

The pollen morphology and exine ornamentation of an important autochthon plum cultivar (Prunus domestica cv. Požegača 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 Požegača 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 μm) of genotype PdP4 was attained in media with 20% PEG.