Assignment of RFLP linkage groups to chromosomes using monosomic F1 analysis in hexaploid oat

Abstract

The availability of molecular genetic maps in oat (Avena spp.) and improved identification of chromosomes by C-banding are two recent developments that have made locating linkage groups to chromosomes possible in cultivated hexaploid oat, 2n=6x=42. Monosomic series derived from Avena byzantina C. Koch cv Kanota and from Avena sativa L. cv Sun II were used as maternal plants in crosses with the parents, Kanota-1 and Ogle-C, of the oat RFLP mapping population. Monosomic F1 plants were identified by root-tip cell chromosome counts. For marker analysis, DNAs of eight F2 plants from a monosomic F1 were combined to provide a larger source of DNA that mimicked that of the monosomic F1 plant. Absence of maternal alleles in monosomic F1s served to associate linkage groups with individual chromosomes. Twenty two linkage groups were associated with 16 chromosomes. In seven instances, linkage groups that were independent of each other in recombination analyses were associated with the same chromosome. Five linkage groups were shown to be associated 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 lines. The F1 monosomic series represents a powerful cytogenetic tool with the potential to greatly improve understanding of the oat genome.