Genetic variability in grapevine clones of ‘Muscat of Alexandria’

Abstract

Among grapevine cultivars, the ‘Muscat’ family includes several widespread types that share a characteristic pronounced floral aroma and a typical ‘Muscat’ flavor. ‘Muscat blanc a petits grains’ and ‘Muscat of Alexandria’ are the most representative and ancient cultivars. The grapevine cultivar ‘Muscat of Alexandria’ is of great importance within the Valencia and Vinos de Alicante PDOs (Protected Designations of Origin, a prestigious Spanish regional product classification). Fruits from these cultivars are the basis of various appreciated wines, also being consumed as table grapes or used for raisin production. We used a set of selected simple sequence repeat (SSR) markers to confirm the identity of different clones of ‘Muscat of Alexandria’, some of them showing differential ampelographic traits. Additionally, we found intravarietal genetic variability using amplified fragment length polymorphism (AFLP) markers. Now, more accurate genotyping has been conducted by GBS (genotyping by sequencing). The GBS generated 2-4 million reads per sample, 85% of which were mapped to the reference genome developed by the French-Italian consortium (Vitis vinifera IGGP 12×). Around 40,000 SNPs were identified, with a coverage greater than 10×. Polymorphisms between and within the analyzed clones were found. Experimental validations of the identified SNPs will provide markers to fingerprint these clones accurately. They will be also suitable for association studies or to develop molecular markers useful in selection programs.