Identification by SNP Analysis of a Major Role for Cayetana Blanca in the Genetic Network of Iberian Peninsula Grapevine Varieties

Abstract

Cayetana Blanca is a grapevine variety widely distributed in the Iberian Peninsula (Spain and Portugal). In addition a wide list of synonyms and its presence in Northern Africa point to a long history of cultivation. In this work we aimed to identify its genetic relationships with other Iberian and Mediterranean cultivars using a panel of SNP markers. A total of 243 SNPs and four chloroplast microsatellite loci allowed for identifying synonyms, trios (parents and offspring) and duos (parent-offspring) relationships. A total of six trios including Cayetana Blanca as a parent were found and supported by very high LODs. Five of the trios have the variety Alfrocheiro Preto as the other parent and gave rise to cultivars used in Portugal: Cornifesto, Camarate, Mouratón, Malvasia Preta and Periquita. The Spanish cultivar Jaén Tinto is confirmed to be an offspring of Cayetana Blanca and Listán Prieto. Additionally, we detected synonyms and duos which in some cases were not anticipated beforehand. This study sheds light on the genetic relationships among cultivars from Spain and Portugal related to the important cultivar Cayetana Blanca. The parents of Cayetana Blanca remain unknown, while the geographical origin of Cayetana Blanca could be a border region between Portugal and Spain. The results show that this cultivar has had a relevant impact in the viticulture of that area. As shown in other European regions, viticulture in the Iberian Peninsula is also marked by the impact of certain varieties that have worked as progenitors of many present cultivars. The results also show the interconnection between Portuguese and Spanish viticulture. Finally, we also demonstrate that SNP are a powerful tool for parentage inference in grapevine.