Genetic diversity and relationships among Italian and foreign almond germplasm as revealed by microsatellite markers

Italian germplasm is characterized by a wide diversity rapidly developed determining a massive geneticpool of cultivars in several growing areas. On the whole, regions of southern Italy, and in particular Sicily,were considered as one of the main trade routes along which almond was spread throughout the shoresof the Mediterranean Sea. In this work, 9 SSR markers have been used to analyze 113 almond cultivars andaccessions coming from ex-situ conservation, including most of almond genotypes spread in Sicily andApulia and foreign cultivars from Mediterranean, American and Australian areas in order to determinethe level of genetic diversity within Italian genotypes and elucidate phylogenetic and possible parentagerelationships between Italian accessions and foreign germplasm. Distance and model-based analysesrevealed a high level of variability both among and within geographical areas. In total, 159 alleles weredetected altogether, which identified the average of 44 genotypes in the population investigated. Thewide genetic diversity detected in the Italian almond cultivars represents a valuable source of variabilityto be applied for breeding. These data represent the first overview of genetic diversity among Italianalmond cultivars using molecular markers.