Microsatellite polymorphism in Tunisian pomegranates (Punica granatum L.): Cultivar genotyping and identification

Specific microsatellites (SSRs) markers were used to characterize a set of 32 Tunisian
pomegranate (Punica granatum L.) cultivars. Using 13 SSR primers, a total of 40 alleles and
46 genotypes have been identified. As a result, data proved that a high level of polymorphism
characterizes the Tunisian pomegranate germplasm at the DNA level. The
derived Neighbour-joining (NJ) dendrogram constructed using DAS genetic distances
exhibited a genetic diversity structured independently from the geographical origin of
cultivars and their denomination. This result suggested that a common genetic basis may
characterize Tunisian pomegranate cultivars despite their phenotypic divergences.
Furthermore, based on the multilocus genotypes a cultivar’s identification key has been
established and permitted to unambiguously differentiate between varieties. The obtained
results are discussed in term of establishment and management of a national collection of
pomegranate varieties, conformity checks, identification of homonyms and synonyms, and
screening of the local resources. Furthermore, this microsatellite-based key is a first step
towards a marker-assisted identification pomegranate database.