Palynological characterization, germination potential and pollen tube growth of direct producer hybrids Noah and Othello (Vitis genus)

Palynological characteristics of the two direct producer hybrids are very similar, as they belong to Vitis genus, even if the genitors are different. Germination potential is higher for Othello cultivar. In vitro, the pollen tube growth is fast and increases significantly within the first 24 h on mediums with 15% and 25% sucrose. It is proved that the longest pollen tubes are correlated with style's length of the flower of the two genotypes. Pollen tube abnormalities are more frequent in Noah than in Othello.