THE EUROPEAN Prunus MAPPING PROJECT: RESULTS ON PEACH (P. persica )

¹ Institut National de la Recherche Agronomique (INRA). Unité de Recherches sur les Espèces Fruitrières et la Vigne BP81, 33883 Villenave d'Ornon, France.

² Institut National de la Recherche Agronomique(INRA) Station de Recherches Fruitrières Méditerranéennes Site Agroparc, 84914 Avignon, France.

³ Istituto Sperimentale per la Frutticoltura (ISF) Via Fioranello n. 52 Ciampino Aeroporto, 00040 Roma, Italy.

⁴ Institut de Recerca i Tecnologia Agroalimentaries (IRTA), Departement de Genetica Vegetal, Carretera de Cabrils s/n, 08348 Cabrils, Spain.

Three crop populations were selected for marker analysis (i) JxF, an F₂ intraspecific population of 63 trees issued from a 'Jalousia' x 'Fantasia' cross (ii) SxD, an F₁ interspecific population of 77 trees issued from a 'Summergrand' x P. davidiana cross (iii) PxF, a back cross population of 72 trees issued from the cross ('IF7310828' x P. ferganensis) x 'IF7310828'. Four maps were constructed (JxF, 'Summergrand', P. davidiana, PxF) using RFLP, RAPD markers and with AFLP markers for JxF. A common set of probes were used for RFLP so that the homology between linkage groups was determined and syntheny was analysed. Several monogenic characters were mapped: male-sterility, leaf gland (globose, reniform or eglandular) and fruit characters as the shape of the fruit (flat or round), skin hairiness, flesh adhesion and non-acidity of the fruit. The polygenic characters measured during the project concerned vegetative characters (internode length, tree height, blooming time, ripening time, productivity), fruit quality (skin color, fresh weight, pH, titratable acidity, soluble solid content, sugar and organic acid contents) and disease resistance (powdery mildew and peach leaf curl). Several characters were measured during different years and in several populations. QTLs were detected for all the studied characters.