Genetic variability assessment in ‘Muscat’ grapevines including ‘Muscat of Alexandria’ clones from selection programs

Genetic variability is needed to face environmental changes and pathogen constrains. In addition, the search for intravarietal variability contributes to the avoidance of genetic erosion, preserving clones that are adapted to particular conditions. Variability is also important to diversify grapevine-derived products. In this work, we have analyzed the genetic variability of ‘Muscat germplasm’ including samples from neglected vineyards from Alicante and Valencia provinces, accessions of the germplasm collections of ‘Colección de Vides de El Encín’ (Alcalá de Henares, Madrid) and ‘La Casa de las Vides’ (Agullent, Valencia), accessions supplied by nurseries of Valencia province, and ‘Muscat of Alexandria’ clones selected using differential ampelographic characteristics in selection programs (La Marina, Alicante). Fifteen microsatellites (SSRs) were used to study intervarietal variability. The SSR fingerprinting allowed the identification of some accessions, variants, and synonymies. Amplified Fragment Length Polymorphisms (AFLPs) markers and Microsatellite-AFLPs were used to determine the variability attended in ‘Muscat of Alexandria’ accessions. A CAPs (Cleaved Amplified Polymorphic Sequences) marker, recently developed for the discrimination of ‘Muscat’ flavor genotypes using the SNP1822 G>T, was assessed and showed that all the analyzed accessions were ‘Muscat’ flavored. The variation found among the analyzed germplasm is very interesting because variants within ‘Muscat of Alexandria’, ‘Muscat Italia’, and ‘Muscat d’Istambul’ have been identified. In addition, intravarietal genetic variation was found among the analyzed accessions in ‘Muscat of Alexandria’ from selection programs