RFLP mapping of a gene for hairy leaf sheath using a recombinant line from Hordeum vulgare L. ×Hordeum bulbosum L. cross

A gene conditioning hairy leaf sheath character, which was derived from Hordeum bulbosum and designated Hsb, was mapped using a cross between Hordeum vulgare and a H. vulgare/H. bulbosum recombinant line. The Hsb locus was tagged relative to eight RFLP markers detecting three loci on the distal part of chromosome 4HL. The map position suggests that Hsb of H. bulbosum is homoeologous to the gene Hp1 of rye (Secale cereale), which pleiotropically governs the traits hairy leaf sheath and hairy peduncle. It is proposed that the recombination break point between H. vulgare and H. bulbosum chromosomes occured at a position homoeologous compared with the 4L/5L translocation in Triticeae genomes, and may reflect a hot spot for chromosome breakage.Key words: Hordeum vulgare, Hordeum bulbosum, comparative mapping, hairy leaf sheath, RFLP.