Intravarietal Agronomic Variability in Croatian Native Vitis vinifera L. Cultivar Grk with Female Flower and Seedless Berries

Abstract

The Croatian native, Vitis vinifera L. cv. Grk, is one of only a few wine cultivars with a female flower, resulting in two types of berries in the cluster: fully developed seeded (~3.5 g) and undersized seedless (~0.7 g), both ripe at harvest. This study investigated the intravarietal variability of Grk and the impact of the different proportion of seedless berries on grape yield and quality of Grk clones. Significant differences in cluster proportions of seedless berries among Grk clone candidates were determined. A high positive correlation was found between the seedless berry proportion and single berry weight, must tartaric acid content, and free volatile terpenes. These results indicate that it is possible to select clones with a higher proportion of seedless berries, which can then be used to improve the wine quality of Grk.