Genetic diversity of grapevine landraces grown in a traditional vineyard in North Lebanon

Grapevine landraces are exceedingly important due to their direct historical usage as well as their significant ecological relevance as genetic resources. They are of great value as they hold useful traits related to their great adaptability to local agroclimatic conditions or to preferred organoleptic features. In Lebanon, many farmers in traditional and marginal agricultural regions are still persistently growing landraces in their vineyards with desired characteristics. In this work, we investigated the genetic diversity of grapevine landraces cultivated in a private vineyard in Bterram, North Lebanon, using both conventional ampelographic descriptors and molecular markers. An ampelographic analysis based on 20 OIV descriptors for the leaf, cluster and berry revealed a large degree of morphological diversity and enabled the differentiation among all 12 accessions. Molecular analysis using a set of 22 nuclear and three chloroplastic microsatellite markers indicated a significant degree of genetic variation, with 103 alleles and a mean number of 4.12 alleles per marker. The comparison of the genetic profiles of the landraces with those of the accessions conserved in the grape collection at Domaine de Vassal (Montpellier France) showed that four of these landraces matched to known cultivars (such as ‘Blanc de Dellys’) while eight accessions did not match with the 3300 cultivars present in the database. These findings increase our knowledge of Lebanon’s underexploited grapevine germplasm and emphasize the critical role that farmers in marginal areas play in safeguarding it.