SNP marker analysis for validating the authenticity of Tunisian olive oil

Abstract

Olive (Olea europaea L.), which is an important oilproducing crop, is one of the oldest agricultural plant in the Mediterranean basin. The oil obtained is known for its nutritional and healthy benefits compared to other vegetable oils, and can be consumed in its crude form (Roche et al. 2000; Elloumi et al. 2012). Moreover, the olive oil sector plays an important role in the culture and socio-economy of many Mediterranean countries, including Tunisia. Traditionally, genetic variation analyses relying on morphological and chemical markers are insufficient to study the relationship and traceability between cultivars due to the environmental effect on the possibly large phenotype and the chemical composition, thus making it expensive (Busconi et al. 2003; Ben-Ayed et al. 2009, 2013). Recently, several molecular marker types, such as random amplified polymorphic DNA (RAPDs) (Busconi et al. 2003), amplified fragment length polymorphisms (AFLPs) (Pafundo et al. 2005; Grati Kamoun et al. 2006), simple sequence repeats (SSR) (Testolin and Lain 2005; Rekik et al. 2008; Ben-Ayed et al. 2009, 2012, 2014) and single nucleotide polymorphism (SNP) (Reale et al. 2006; Consolandi et al. 2008; RekikHakim et al. 2010) have been developed. These can be used as both detection of DNA polymorphisms and for effective distinction between different cultivars, thus solving traceability without any environmental influence. Despite the potential advantages of using SNPs for the authentication of major crop species as coffee (Spaniolas et al. 2006), to the best of our knowledge, the identification of SNP markers has not yet been documented in olive oil. Compared with other genetic markers, SNPs are beneficial from a technological viewpoint change in a single nucleotide allows the distinction of very similar cultivars. Moreover, these molecular markers requiring short DNA amplicons for genotyping and are genetically stable; their high density