Structural patterns and genetic diversity among oat (Avena) landraces assessed by microsatellite markers and morphological analysis

As a counterweight to genetic erosion, landraces could become important germplasm resources for breeding. In the present study the genetic diversity of 62 Greek and Eastern European oat accessions (seven cultivars and 55 common and red oat landraces collected from 1904 to 1960) was studied using simple sequence repeats and 31 morphological descriptors. High levels of polymorphism were detected and 209 distinctive alleles were identified; on average 14.65 alleles per primer. Both, the principal component analysis derived from the morphological data, and the unweighted pair group method with arithmetic mean from the molecular analysis clustered the oat genotypes according to their type (common and red oats). In addition, the analysis of molecular variation showed that there were noteworthy differences within designated geographic regions. Moreover, a more discrete subpopulation structure was identified based on allele frequency using a Bayesian clustering approach. A clear distinction was evident among the red and common oats suggesting that they should be considered as separate species.