Etude de la variabilité des estérases carboxyliques chez quelques populations naturelles de deux espèces du genre Hedysarum

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Impact of mapped SSR markers on the genetic diversity of apricot (Prunus armeniaca L.) in Tunisia

 Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699International audienceThe impact of mapped microsatellites on the study of genetic diversity of Tunisian apricot accessions was assessed. The genetic variability of 47 traditional apricot cultivars originating from several areas in Tunisia was investigated with 32 polymorphic microsatellite loci selected for their location throughout the eight linkage groups of Prunus genome. The higher polymorphism and greater transportability of these markers among Prunus species were proved by the expected heterozygosity (He=0.56) and Shannon’s index of diversity (I=1.05), indicating that Tunisian apricot germplasm maintained a substantial level of genetic diversity. According to their geographical origin, the genetic differentiation among groups (north, center, and south; Fst=0.04) was lower, while the gene flow among groups was consequent (Nm=4.79), attesting a narrow genetic background of apricot in the country. Both unweighted pair-group method with arithmetic mean dendrogram, based on Nei’s genetic distances and factorial correspondence analysis, separated northern cultivars from central and southern cultivars, revealing the same molecular basis of apricot material in the Center and the South of Tunisia. These results revealed the efficiency of mapped markers for genetic variability measurements compared to randomly ones, however, no advantage was observed considering the genetic relationships among studied accessions

Apricot genetic resource management. New prospects offered by phylo-geographic and association genetic approaches. Application in the mediterranean basin germplasm

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Apricot genetic resource management. New prospects offered by phylo-geographic and association genetic approaches. Application in the mediterranean basin germplasm

International audienceApricot (Prunus armeniaca L.) was introduced from China to the Mediterranean region through at least two majn routes and a large number of cultivars are here developed in the different countries. In order to characterize the actual Mediterranean genetic variability, 251 apricot accessions from France, Spain, Tunisia, and Turkey were investigated with a common set of markers. Twenty five SSR loci, covering the whole Prunus genome were chosen according to their expected polymorphism. Our results confirmed that SSR markers are efticient tools for fingerprinting cultivars and for determining the genetic structure of apricot Mediterranean populations as well. On the base of a Bayesian analysis four main phylogeograpbical groups have been identified: Tunisian, Enropean (Mediterranean & continental), Turkish and a diversification group joining accessions from central Asia to Europe

Apricot diffusion in the mediterranean basin : a serious loss of genetic diversity

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Genetic structure of Mediterranean apricots by SSR fingerprinting

International audienceApricot (Prunus armeniaca L.) is an important fruit species especially in the Mediterranean bassin area. The genetic structure of apricot cultivars in this region was studied in order to shed light on the evolutionary history of this species. A sample of 207 patrimonial accessions was collected from different Mediterranean countries: Algeria, France, Italy, Morocco, Tunisia, Turkey, and Spain. Molecular characterization was performed using 25 SSR markers, selected according to high level of polymorphism, transferability between Prunus species, and localisation over the eight linkage groups of the Prunus genome. Statistical treatment of the dataset was undertaken using a model-based Bayesian clustering analysis implemented in the STRUCTURE program. It allowed assignment of the studied accessions into four distinct genetic clusters (Fst=0.122). A gradient of decreasing genetic diversity from the east to the south-west of the Mediterranean area was also evidenced. An interesting new pattern based on the discrimination of a ‘Maghreb’ cluster was revealed for the first time. These results clearly open new research lines dealing with the establishment of a nested core collection at the Mediterranean level, and with the prospective development of genetic association studies