title: Combination of morphological and molecular markers for the characterization of ancient native olive accessions in Central-Eastern Tunisia.
abstract: Increasing olive germplasm erosion in the coastline of Tunisia has required an imperious conservation of the traditional genotypes before an ultimate disappearance. This region has been relatively neglected in the literature sources of olive identification. In this context, a prospection effort and a preliminary selection of olive accessions belonging to Central-Eastern Tunisia was carried out. Twenty-seven ancient olive accessions were studied by combining molecular and morphological data in order to fingerprint them, and to evaluate their relationships with classical cultivars. Compared to known classic Tunisian olive cultivars, the new prospected olive accessions were well distinguished, presenting a potential use as promising genotypes. The morphological and molecular data showed a high diversity between genotypes. 92 and 63 polymorphic bands were scored using 10 RAPD and 9 SSR markers, respectively. Significant correlation coefficients were obtained among fruit and stone sizes (r=0.90) and among their shapes (r=0.73). The genetic distances obtained with the two DNA marker systems were significantly correlated (r=0.45) according to Mantel's test. No significant correlation was observed between distances based on molecular and morphological markers. UPGMA analysis based on molecular data showed no clear clustering trends according to morphological traits or fruit use. Despite the high genetic variation among accessions in each prospected area, geographical origin seemed to have significant impact on the observed variability. The relationship between morphological and molecular data has confirmed that each marker expressed different aspects of variability. Integration between all markers will be useful for distinguishing new accessions and genotyping local varieties.
authors.affiliation: High Agronomic Institute, IRESA - University of Sousse, 4042 Chott-Mariem, Tunisia; Olive Tree Institute, B.P. 40, 4061 Sousse, Tunisia. Electronic address: ibtissem.laaribi@yahoo.fr.
authors.forename: Ibtissem
authors.initials: I
authors.lastname: Laaribi
authors.affiliation: High Agronomic Institute, IRESA - University of Sousse, 4042 Chott-Mariem, Tunisia.
authors.forename: Hassouna
authors.initials: H
authors.lastname: Gouta
authors.affiliation: High Agronomic Institute, IRESA - University of Sousse, 4042 Chott-Mariem, Tunisia.
authors.forename: Mouna
authors.initials: M
authors.lastname: Mezghani Ayachi
authors.affiliation: High Agronomic Institute, IRESA - University of Sousse, 4042 Chott-Mariem, Tunisia.
authors.forename: Foued
authors.initials: F
authors.lastname: Labidi
authors.affiliation: Olive Tree Institute, B.P. 40, 4061 Sousse, Tunisia; Regional Research Center for Horticulture and Organic Agriculture (CRRHAB), B.P. 57, 4042 Chott Mariem, Sousse, Tunisia.
authors.forename: Messaoud
authors.initials: M
authors.lastname: Mars
mesh_terms: D016000:Cluster Analysis; D005638:Fruit / Q000033:anatomy & histology; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D031658:Olea / Q000235:genetics*; D010641:Phenotype; D019105:Random Amplified Polymorphic DNA Technique; D014416:Tunisia
chemical_list: D005819:Genetic Markers
keywords: Correlation; Corrélation; Descripteurs morphologiques; Mantel test; Morphological marker; Olea europaea L; Olive; RAPD; SSR; Test de Mantel