Caractérisation morphologique, biologique et moléculaire de quelques variétés de figuier (Ficus carica L.).

Abstract

Ficus carica L. is one of the first fruit species cultivated in the world, this species underwent a morphological and agronomical evolution leading to an extensive diversit and to two distinct morphotypes according to the use of figs (fresh and dry). This aims of this study were to make a morphological, biochemical and molecular characterization of cultivars tested. The results were proved an important phenotypic variability of the fig heritage according to the descriptors of IPGRI (International Plant Genetic Resources Institute) and CIHEAM (Centre International de Hautes Etudes Agronomiques Méditerranéennes) (2003). Morphological study has shown that the fruit characters appear to be more discriminating than those of the leaf. The biochemical study of cultivars tested by characterized them with phytochemical screening and evaluating their antimicrobial activities. The preliminary evaluation of the phytochemical composition of the different treated parts made it possible to highlight the presence of some chemical groups. We have shown that aqueous methanol is the best extractor of secondary metabolites. The in vitro evaluation of the antibacterial activity of the methanolic extract of F.carica leaves showed a high antibacterial activity towards Kleibseilla and E. coli and extracts obtained from fruits of F.carica were inactive towards all tested bacterial strains. Similarly, a tendency was shown indicating that the richest extracts on flavonoids exhibit the higher antibacterial activities. Molecular analysis of the genetic diversity of Algerian and Turkish fig trees based on twenty three pairs of iBPS primers and sixteen pairs of SSR primers allowed us to count a total of 63 amplified DNA fragments for iPBS markers and 25 Alleles for SSR markers were identified with an average of 2.7 and 1.6 per primer, respectively. The average value of the polymorphic information content (PIC) for the iPBS markers (0.73) was higher than that of the SSR markers (0.69). Applying the neighbor-joining method to the combined iPBSretrotransposon and SSR data, the fig genotypes were clustered into two groups. We were able to highlight the diversity within the collection as well as the rapprochement between the Algerian and Turkish pool. Therefore, this study opens great prospects for the integration of these genetic resources and their appropriate use in new breeding programs for fig trees in countries like Algeria for their optimized management. Moreover, the fig tree, with its multiple roles of valorization of the agricultural lands and fight against the erosion, of the fixation of the populations in the arid zones, constitutes the main fruit speculation which can guarantee the sustainable development of these zones and the creation of a productive and sustainable agro-system.