Assignment of RFLP linkage groups to chromosomes using monosomic F-1 analysis in hexaploid oat

The availability of molecular genetic maps in oat (Avena spp.) and improved identification of chromosomes by C-banding are two recent developments tha t have made locating linkage groups to chromosomes possible in cultivated h exaploid oat, 2n=6x=42. Monosomic series derived from Avena byzantina C. Ko ch cv Kanota and from Avena sativa L. cv Sun II:were used as maternal plant s in crosses with the parents, Kanota-1 and Ogle-C, of the oat RFLP mapping population. Monosomic F-1 plants were identified by root-tip cell chromoso me counts. For marker analysis, DNAs of eight F-2 plants from a monosomic F -1 were combined to provide a larger source of DNA that mimicked that of th e monosomic F-1 plant. Absence of maternal alleles in monosomic F(1)s serve d to associate linkage groups with individual chromosomes. Twenty two linka ge groups were associated with 16 chromosomes. In seven instances, linkage groups that were independent of each other in recombination analyses were a ssociated with the same chromosome. Five linkage groups were shown to be as sociated with translocation differences among oat lines. Additionally, the results better-characterized the oat monosomic series through the detection of duplicates and translocation differences among the various monosomic li nes. The F-1 monosomic series represents a powerful cytogenetic tool with t he potential to greatly improve understanding of the oat genome.