Geographical distribution of a chromosome 7C and 17 intergenomic translocation in cultivated oat

Previous cytogenetic and molecular genetic investigations have shown variation for the presence of intergenomic translocation segments on chromosomes 7C and 17 of common cultivated oat (Avena sativa L,, 2n = 6x = 42) and red oat (A, byzantina K, Koch, 2n = 6x = 42), The objective of this work was to determine the geographic distribution of these translocation segments in 197 landraces and cultivars using C-banding, Genotypes were selected primarily on the basis of diversity of geographic origins, particularly within the Mediterranean-Near Eastern center. Eighty-nine percent of traditional A. byzantina-type pe accessions, mostly from the lowland Mediterranean basin and Indian subcontinent, were of the nontranslocation type, Ninety-seven percent of traditional A. sativa and hulless (A. sativa subsp, nuda) genotypes possessed the 7C-17 translocation (Delta 7C-17) segments. Presence or absence of the Delta 7C-17 was more loosely associated with spring vs. winter growth habit, but still highly significant. The results support the hypothesis that common cultivated oat and red oat are distinct races of the hexaploid biological species and were domesticated independently of one another.