Ficus carica L. (2n=26) is one of the 750 species of the genus Ficus (Berg 1989; Falistocco and Antonielli 2002). It is the oldest fruit crop known as a gynodioecious and insect pollinated species (Beck and Lord 1988; Kislev et al. 2006). Its utilization consists of ecotypes called common figs (unisexual female trees) and caprifigs (bisexual with functional male trees) occurring in similar frequencies in wild populations (Valdeyron and Lloyd 1979). This fruit crop is wide spread in the Mediterranean basin countries since it is well adapted either to different soils or climates (Mars 2003). In Tunisia, the fig germplasm consists of numerous landraces mainly selected by farmers for their fruit qualities and maintained in orchards where fruit types are unequally represented. Hodgson (1931) reported the prevalence of the “Smyrna” (crossbreeding) ecotypes in southern Tunisia, while the “common” (parthenocarpic) and “Smyrna” ones are equally spread in the northern Tunisia. Thus, a wide phenotypic diversity characterizes the large number of ecotypes distinguishable by taste; color and flavor of fruits (Rhouma 1996; Mars et al. 2007). In addition, fig trees represent the principal component of several agro-ecosystems in the southern areas such as at the Jessours region (Matmata, Beni Khédache and Douiret) and constitute the second fruit crop in the Tunisian oases (Mars 1995, 2003). In spite of its ancient cultivation, fig groves remain sporadic and consisted of a few plantations where superior fruity cultivars have been recently established in the central and the northern areas cultivars (Mars et al. 2007). It should be stressed that since several decades, the local germplasm is seriously threatened by severe genetic erosion due to biotic and abiotic stresses such as intensive urbanization and the fig mosaic disease. Moreover, problems of synonymy are still occurring since cultivars’ appellation is mainly based on the fruit parameters. As a consequence, the precise number of varieties is unknown. Therefore, establishment of strategies aiming at the conservation and the evaluation of the local germplasm has become imperative. Therefore, recent investigations (prospecting and collection of cuttings) have been made and permitted to identify about 100 ecotypes that are ex situ conserved in different collections at the “Institut Supérieur Agronomique, (ISA)” of Chott Meriem, the “Institut des Régions Arides (IRA)” of Medenine, the “Centre de Recherches Phoénicicoles, (CRPh)” of Degache, the “Commissariat Régional au Développement Agricole, (CRDA)” of Gafsa and the “Groupement Interprofessionnel des Fruits, (GIF)” of Sbikha (Lahbib 1984; Mars et al. 1994; Rhouma 1996; Mars et al. 2007). However, the conservation management of this relatively high number of existing ecotypes with different synonyms and variable commercial values requires the development of reliable methods aiming at their fingerprinting. For this purpose, studies have reported the use of pomologic, morphometric, horticultural traits and isozyme markers to examine the genetic diversity within and between ecotypes housed in these collections (Valdeyron and Crossa-Raynaud 1950; Ben Salah et al. 1995; Hedfi et al. 2003; Chatti et al. 2004a; Salhi-Hannachi et al. 2003). However, a lack of polymorphism levels is occurring since these parameters are highly influenced by the environmental conditions and/or the plant development stage. To overcome this inconvenience, the use of molecular markers such as random amplified polymorphic DNA (RAPDs), inter simple sequence repeats (ISSRs) and random amplified microsatellite polymorphism (RAMPO) have been developed in Tunisian figs (Chatti et al. 2004b, 2007; Salhi-Hannachi et al. 2004). These studies have proved that a high genetic diversity characterizes the Tunisian fig germplasm. Nevertheless, these studies are less rewarding by regards of the some limitation of the used markers and/or the relatively little number of ecotypes involved. Therefore, we become interested in the use of microsatellites or simple sequence repeats (SSRs) known for their reliability in plant population genetic diversity assessment. Such markers are of advantages over the mentioned markers since microsatellites: (1) are very common in the eukaryotes’ genomes (Wang et al. 1994; Smulders et al. 1997), (2) are of co-dominant and of mendelian inhertitance, (3) they permit to detect high polymorphisms at the infra specific level (Testolin et al. 2000) and, (4) are efficient to unambiguously distinguish genotypes (Zehdi et al. 2004). Moreover, we have successfully reported the use of SSRs to survey the genetic diversity in sixteen Tunisian fig ecotypes (Saddoud et al. 2005). Therefore, taking into account the advantages of the microsatellites, we have enlarged the number of Tunisian ecotypes in situ and ex situ conserved in order to have an overview of the genetic diversity structuration in the local germplasm with the use of SSRs.
The present study portrays the evidencing of SSRs in a set of 72 local ecotypes originated from different Tunisian areas and the achievement of their fingerprinting. In addition, data have permitted not only to determine the between fig landraces and geographic groups’ relationships but also to establish a cultivars’ identification key. Data are discussed in relation to the true-to-typeness control of Tunisian fig cuttings.