Early Screening of Moroccan Grapevine Cultivars through Ampelographic

Abstract

The primary challenge in viticulture research lies in effectively identifying grapevine cultivars amidst their vast diversity and the complexities of local nomenclature. This study aims to address this challenge with an ampelographic descriptive study. The focus is on categorizing grapevine cultivars based on shared characteristics, with an emphasis on identifying the most distinctive descriptors. To accomplish this, we conducted an initial ampelographic study involving 44 indigenous Moroccan grape varieties cultivated in the experimental domain of Larache (INRA, Morocco). This comprehensive assessment encompassed 20 qualitative and quantitative descriptors established by the International Organization of Vine and Wine (OIV). Our findings unveiled considerable variability among the grape varieties. We were able to identify two groups, although without strong discrimination. The color of the upper surface of the young leaf blade, density of prostrate hairs between the main veins on the lower surface of the young leaf, shape of the mature leaf blade, profile of the cross-section of the mature leaf blade, shoot tip type of the young shoot, color of the dorsal side of the internodes of the young shoot, and the time of bud burst can be the most discriminatory descriptors. Furthermore, several grapevine cultivars from both groups share similar attributes. This shared similarity complicates their identification during the vegetative phenological stage. Therefore, it is imperative to await the grape development stage or conduct biochemical and molecular tests for precise characterization.