Genetic variation within and between winter wheat genotypes from Turkey, Kazakhstan, and Europe as determined by nucleotide-binding-site profiling

The genetic diversity within wheat breeding programs across Turkey and Kazakhstan was compared with a selection of European cultivars that represented the genetic diversity across eight European countries and six decades of wheat breeding. To focus the measure of genetic diversity on that relevant to disease-resistant phenotypes, nucleotide- binding-site (NBS) profiling was used to detect polymorphisms associated with the NBS motifs found within the NBS--leucine-rich repeat (LRR) class of resistance (R) genes. Cereal-specific NBS primers, designed specifically to the conserved NBS motifs found within cereal R-genes, provided distinct NBS profiles. Although the genetic diversity associated with NBS motifs was only slightly higher within the Eastern wheat genotypes, the NBS profiles produced by Eastern and European wheat lines differed considerably. Structure analysis divided the wheat genotypes into four groups, which compared well with the origin of the wheat genotypes. The highest levels of genetic diversity were seen for the wheat genotypes from the Genetic Resource Collection held in Ankara, Turkey, as wheat genotypes within breeding programs were genetically more similar. The wheat genotypes from Kazakhstan were the most similar to the European cultivars, reflecting the significant number of eastern European cultivars used in the breeding program in Kazakhstan. In general, the NBS profiles suggested that NBS-LRR R-gene usage in winter wheat breeding in Turkey and Kazakhstan differed from that deployed in European cultivars. Key words: disease resistance, genetic diversity, nucleotide-binding-site profiling, Puccinia striiformis f.sp. tritici, yellow rust, wheat. Resume : La diversite genetique au sein de programmes d'amelioration genetique du ble en Turquie et au Kazakhstan a ete comparee a celle presente chez une collection de cultivars europeens representatifs de la diversite genetique dans huit pays europeens au fil de six decennies de selection chez le ble. Afin de focaliser la mesure de la diversite genetique sur la resistance aux maladies, des profils NBS (<< NBS profiling >>) ont ete employes pour detecter le polymorphisme associe aux motifs de liaison nucleotidique (NBS) au sein des genes de resistance (genes R) appartenant a la classe des genes NBS-LRR. Des amorces specifiques des motifs NBS des cereales, concues specifiquement sur la base des motifs conserves chez les genes R des cereales, ont permis de generer des profils distincts. Tandis que la diversite genetique associee aux motifs NBS etait tres legerement superieure au sein des genotypes europeens de ble, les profils NBS obtenus chez les bles orientaux et europeens differaient de maniere considerable. Une analyse de structure a divise les bles en quatre groupes conformement a l'origine des genotypes. La plus grande diversite genetique a ete observee au sein des genotypes de la Genetic Resource Collection d'Ankara en Turquie, tandis que les genotypes appartenant a des programmes de selection varietale etaient plus semblables. Les genotypes du Kazakhstan etaient les plus semblables aux cultivars europeens, ce qui reflete le nombre significatif de cultivars d'Europe de l'Est employes dans les programmes de selection au Kazakhstan. En general, les profils NBS suggerent que l'emploi de genes R de type NBS-LRR au sein des programmes de selection du ble en Turquie et au Kazakhstan differe de celui au sein des cultivars europeens. Mots-cles : resistance aux maladies, diversite genetique, profil NBS, Puccinia striiformis f. sp. tritici, rouille jaune, ble. [Traduit par la Redaction]
Introduction Turkey is a major producer and exporter of wheat. As Turkey lies on the edge of the Fertile Crescent and within the Vavilov centre for wheat biodiversity and domestication, [...]