Assessing Genetic Diversity of Wheat From Turkey and Great Plains Using Morphological Characters and SSR Marker.

'Turkey' wheat is the original hard red winter wheat landrace introduced from Turkey to the Great Plains of North America. Many modern Great Plains wheat cultivars are either derived from Turkey wheat or its related lines.  The genetic diversity of wheat cultivars from Turkey and the US Great Plains were studied to investigate how the two gene pools have differentiated over time through breeding. Twenty-two Turkish and twenty-three US Great Plains wheat cultivars, released between 1874 and 2007, were selected for a genetic diversity study using molecular marker (SSR), agronomic, and quality trait data. Field experiments were conducted in three environments in Nebraska to evaluate nine agronomic traits and provide grain for evaluating four quality traits. The cultivars and cultivar by environment interactions for all agronomic and quality traits were significant. Most Turkish wheat cultivars were injured by the Nebraska winter and hence showed lower grain yields. UPGMA method based on SSR clustered the forty-five wheat cultivars into five groups and the clustering largely followed their country of origin and pedigree. According to this cluster analysis, modern Great Plains wheat cultivars diverged from Turkish wheat cultivars by breeding for adaptation. Historic Great Plains wheat cultivars were grouped with the Turkish wheat cultivars by SSR. Also, four of the five historic cultivars were clustered in a group with the Turkish wheat cultivars by agronomic traits. The clustering analysis based on wheat quality traits indicated six clusters that often included both US Great Plains and Turkish wheat cultivars. This result may indicate parallel breeding criteria on quality traits in both programs. It is possible to use those Turkish wheat cultivars most closely related to Great Plains wheat cultivars as potential sources of germplasm to add new alleles into the US Great Plains wheat without adding too much exotic genetic diversity.