Comprehensive ampelographic and biochemical profiling of exotic grapevine (Vitis vinifera L.) cultivars grown under semi-arid conditions

Grapes (Vitis vinifera L.) belong to the genus Vitis, and are a member of the family Vitaceae. It is a diverse and commercially important fruit plant due to its versatile use in industries as well as in table and raisins, it is grown worldwide from subtropical to temperate zones. Unfortunately, despite its potential and demand in Pakistan, grapes are still considered a minor fruit crop. Potohar is the most neglected area in terms of grape production in Pakistan. The progressive farmers in this region have imported genotypes from different parts of the world, but these cultivars are yet to be characterized and registered. For this purpose, this study contained 17 grape cultivars, which were characterized based on ampelography and biochemical traits for determining correlation and variation among them. For Ampelographic characterization of grapes, 41 traits were selected from the UPOV descriptor. The cultivars included Baco Noir, Black magic, Dubovsky Pink, early white, Glory to Ukraine, Gold Finger, Himrod, Jupiter, King ruby, Kishmish Velez, Lakemont, Long-awaited, NARC black, Sugra one, Sultana C, Summer royal, and Vitro black. For observing variation, principal component analysis was used and the variation among grape cultivars was illustrated in Agglomerative Hierarchical Clustering. The results revealed great variation in Ampelographic traits among cultivars. In agglomerative hierarchical clustering, the dendrogram revealed that variation between the clusters was 78.88% while the variation within the clusters was 28.12% and cultivars were grouped into two clusters. Mature leaf, young leaf, and berry were the most responsible factors for this variation among grape cultivars. The phenological calendar revealed Early white and Surgraone as the earliest maturing cultivars. Biochemical parameters were also helpful in depicting the relationship among grape cultivars having non-reducing sugar and ascorbic acid as the most significant tool for variation among grape cultivars. Dendrogram developed based on biochemical traits. According to the dendrogram, the variation between the clusters was 58.92%, while the variation within the cluster was 41.8%, and cultivars were grouped into three clusters. The results will be helpful in the registration of grape cultivars present in the Potohar region.