Diversity and Genetic structure of the Spanish collection of durum wheat (Triticum turgidum L) landraces

The objectives of this study were to assess diversity and genetic structure of a collection of Spanish durum wheat (Triticum turgidum L) landraces, using SSRs, DArTs and gliadin-markers, and to correlate the distribution of diversity with geographic and climatic features, as well as agro-morphological traits. A high level of diversity was detected in the genotypes analyzed, which were separated into nine populations with a moderate to great genetic divergence among them. The three subspecies taxa, dicoccon, turgidum and durum, present in the collection, largely determined the clustering of the populations. Genotype variation was lower in dicoccon (one major population) and turgidum (two major populations) than in durum (five major populations). Genetic differentiation by the agro-ecological zone of origin was greater in dicoccon and turgidum than in durum. DArT markers revealed two geographic substructures, east-west for dicoccon and northeast-southwest for turgidum. The ssp. durum had a more complex structure, consisting of seven populations with high intra-population variation. DArT markers allowed the detection of subgroups within some populations, with agro-morphological and gliadin differences, and distinct agro-ecological zones of origin. Two different phylogenetic groups were detected; revealing that some durum populations were more related to ssp. turgidum from northern Spain, while others seem to be more related to durum wheats from North Afric

Creación de la colección nuclear española de trigo duro

Varios grupos de investigación españoles se han coordinado para crear la colección nuclear española de trigo duro (Triticum turgidum L.). Esta colección estará formada por variedades locales, cultivares antiguos y especies afines conservadas en el CRF-INIA. Como paso previo se han seleccionado 200 entradas que maximizan la variabilidad genética de la colección. Para ello se han recopilado, sistematizado y elaborado los datos geográficos, de caracterización y evaluación disponibles de proyectos anteriores. Las entradas han sido clasificadas en 9 zonas agro-ecológicas y cinco grupos taxonómicos, y elegido en cada provincia aquellas que incluyen mayor variabilidad en altitud y tipo de suelo de la zona de recolección, así como en caracteres agro-morfológicos, bioquímicos y/o moleculares. Posteriormente se ha confirmado que la variabilidad genética estudiada está recogida en las 200 entradas seleccionadas

Variablilidad genética de gliadinas en la colección de trigo duro del CRF-INIA de acuerdo a la taxonomía y la zona agroecológica de origen.

Se ha analizado la variabilidad genética para gliadinas, por grupos taxonómicos y zonas agro-ecológicas, en una muestra de la colección española de trigo duro (Triticum turgidum L.). La diversidad genética total fue alta (Ht=0,80) siendo la variación intra grupos mayor que entre grupos para la ssp. (dicoccon, durum y turgidum) y la zona. Las tres ssp. se separaron claramente, y mostraron alelos únicos para los loci analizados. La ssp. dicoccon mostró la mayor proporción de diferenciación entre zonas, especialmente para el locus Gli-B1. La ssp. turgidum presentó la mayor variabilidad, sobre todo en las variedades del norte y del este del país. La ssp. durum mostró menor variación entre zonas, pero con una separación de la zona norte del resto de las zonas, que se agruparon siguiendo un patrón esteoeste. El mayor número de alelos locales se detectó en las variedades del sur. En las tres ssp. se detectaron diferencias significativas entre zonas para los alelos de gliadinas

Genetic diversity and association mapping for agromorphological and grain quality traits of a structured collection of Spanish durum wheat

Durum wheat (Triticum turgidum L. subsp. durum) is a crop of strategic importance in the Mediterranean area. However, the massive introduction of homogeneous and more productive modern cultivars have contributed to greatly reduce its genetic diversity. Wheat landrace collections contain a wide genetic diversity and constitute an easily transferable and valuable source of genetic variation for agronomical, morphological, adaptive and quality traits. A durum wheat collection of Spanish landraces comprising accessions of the three main inter-fertile subspecies (durum, turgidum and diccocon) was evaluated in a previous work using several molecular marker systems. The genetic diversity and agromorphological traits were correlated with geographic and climatic features. The broad variation found for all the evaluated traits underlined the large genetic variability of the collection (Ruiz et al. 2012). These study allowed the creation of the Spanish durum wheat core collection (Ruiz et al. 2013). Association mapping was performed for 18 agromorphological and grain quality traits in a collection of 183 Spanish landraces. A total of 85 stable MTAs (marker?trait associations) were identified for agromorphological and quality parameters, some of them common among subspecies and others subspecies-specific. For all the traits, MTAs explaining more than 10?% of the phenotypic variation were found in any of the three subspecies. The validation of several adaptive and quality trait MTAs by combining the association mapping with an analysis of the signature of selection, identifying the putative gene function of the marker, or by coincidences with previous reports, showed that this approach was successful for the detection of MTAs and the high potential of the collection to identify marker?trait associations. Novel MTAs not previously reported, some of them subspecies specific, have been described and provide new information about the genetic control of complex traits (Giraldo et al. 2016).The genetic characterisation and association studies of different wheat germplasm sets will provide researchers comprehensive information of the tetraploid wheat gene pool and the tools to improve the characterisation and utilisation of this germplasm