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87 Pags.- 3 Tabls.- 5 Figs.- 1 Suppl. Fig.- 5 Suppl. Tabls. The definitive version is available at: http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1744-7348, The nature and structure of genetic diversity in the Spanish apple germplasm preserved at the national level was widely unknown, since studies performed to date on this topic have been exclusively carried out at the regional scale. Here, 1453 accessions from Spanish collections of Malus × domestica were evaluated with a common set of 13 SSR (Simple Sequence Repeats) markers in order to estimate genetic diversity, to identify the underlying genetic structure and to unravel the relationships among them and among a wide set of international cultivars for reference. In total, 737 unique genotypes were identified, 581 diploids and 156 triploids. Using a model-based Bayesian clustering procedure, two reconstructed populations were obtained for diploid genotypes; one retaining only Spanish cultivars (42% of genotypes), and a second containing all foreign cultivars the latter exhibiting evidence supporting the existence of a secondary sub-structure. Similarly, analysis performed on the 156 triploid genotypes also revealed two reconstructed populations; one exclusively associated with local Spanish genotypes (44%). The Jaccard coefficient allowed clustering by UPGMA (Unweighted Pair Group Method) diploid and triploid genotypes, and remarkable differences in allelic composition among the different partitioning levels were found. AMOVA analyses showed moderate but significant differentiation among the main groups (0.08 ≤ FST ≤ 0.12). Our results highlight an important fraction of the Spanish apple germplasm that constitutes a differentiated genepool with respect to the international and commercial apple cultivars. Moreover, the extent of the Spanish genetic diversity was spatially distributed along the northern Iberian Peninsula, suggesting an extensive migration of genotypes along the country. This study is the first valuable action for genetic conservation of apple at the national scale, and constitutes a decisive step towards the definition of a Spanish core collection that will be useful for further studies in dissecting the genetic control of important horticultural traits through genome-wide association analysis in apple., This work was supported by INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria), under the Project: 'Harmonization of the methodology of characterization, assessment of genetic diversity and definition of the core collection of the apple germplasm conserved in Spanish genebanks (ref. RF2011-00017-C05)'.

1 Pag., A total of 1543 accessions from Spanish collections of Malus x domestica Borkh were evaluated with a set of 13 SSRs, including 11 recommended by ECP/GR Malus/Pyrus WG, in order to estimate their genetic diversity and to identify the genetic structure and relationships among their accessions, as part of the objectives of the project funded by INIA “Harmonization of the methodology of characterization, assessment of genetic diversity and definition of the core collection of the apple germplasm conserved in Spanish genebanks”.

2 Pags., La Red de Colecciones de manzano del Programa Nacional de Recursos Fitogenéticos integra, entre otras, a las colecciones situadas en la Universidad Pública de Navarra (UPNA), el Centro de Investigaciones Agrarias de Mabegondo (CIAM), Cabildos (Tenerife, La Palma y Gran Canaria), la Universidad de Lleida (UdL), el Servicio Regional de Investigación y Desarrollo de Asturias (SERIDA), la Estación Experimental de Aula Dei-CSIC (EEAD) y el Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA). Estas colecciones comprenden mayoritariamente cultivares locales prospectados en sus respectivas regiones y, en conjunto, representan la práctica totalidad de áreas productoras de manzano del país. Las colecciones habían sido caracterizadas, total o parcialmente, con caracteres morfológicos, agronómicos y moleculares, pero los métodos, caracteres y marcadores que se emplearon no estaban estandarizados, por lo que para evaluar de forma global la diversidad conservada por la Red era preciso realizar un trabajo previo de armonización. En este contexto, en 2012 se inició el Proyecto Coordinado "Armonización de la metodología de caracterización, evaluación de la diversidad genética y definición de la colección nuclear de los recursos genéticos de manzano conservados en los Bancos de Germoplasma españoles" (RF2011-00017-COS-OO), financiado por el INIA, e integrado por las colecciones citadas anteriormente. Su objetivo principal es el de optimizar el manejo de los recursos genéticos del manzano conservado en España, desarrollando e implantando metodologías y criterios comunes para la caracterización morfológica, agronómica, tecnológica y molecular de las colecciones. En esta comunicación presentamos los primeros resultados obtenidos de la armonización de las caracterizaciones moleculares., Este trabajo ha sido financiado por el proyecto INIA RF2011-00017-C05-00.