Research PaperComparison of pollen quality in Vitis vinifera L. cultivars

•Pollen quality is essential to enhance grape productivity.•Vitis vinifera L. pollen viability, germination and aperture numbers were studied.•Pollen viability was high but the germination vary among the cultivars studied.•Tricolporated pollen prevailed, but pollen with one, two or four apertures was present.•Knowledge on pollen quality is essential to support sustainable agronomic decisions.

Pollen quality of 15 cultivars of Vitis vinifera L. was studied in this work. Pollen viability was tested by the fluorochromatic reaction and germination was analyzed by in vitro assays, using two different media. Differences among cultivars in the number of pollen apertures were observed under light microscope. All the cultivars studied showed a higher percentage of tricolporated pollen, however, pollen grains containing one, two or four apertures were also observed. The cultivar Loureiro was the one with the higher percentage of pollen grains with four apertures (3.8%) and Touriga Nacional presented 100% of tricolporated pollen grains. The viability analysis showed that 13 cultivars presented values higher than 50%, with 8 cultivars reaching values above 75%. The pollen germination rates vary greatly for the grapevine cultivars studied, three cultivars show low values of germination (under 14%) in the two media tested, which were Touriga Nacional, Cabernet Franc, and Cabernet Sauvignon while others presented high values of germination like Castelão, Loureiro, Malbec and Petit Verdot. No significant statistical differences between the percentages of germination in the two media studied were found for the majority of cultivars analyzed.