Mapping of resistance against Barley mild mosaic virus-Teik (BaMMV) - an rym5 resistance breaking strain of BaMMV - in the Taiwanese barley (Hordeum vulgare) cultivar 'Taihoku A'

The Taiwanese barley (Hordeum vulgare L.) cultivar Taihoku A, which has been described as resistant to Barley mild mosaic virus (BaMMV), Barley yellow mosaic virus (BaYMV) and BaYMV-2, contains the BaMMV resistance gene rym13 located on chromosome 4HL. Furthermore, Taihoku A shows resistance to the newly detected virus strain BaMMV-Teik, which is able to overcome the resistance gene rym5. By analysing a set of 154 DH-lines of the cross Taihoku A x Plaisant it turned out that resistance to BaMMV-Teik is inherited in a monogenic manner, the gene located on chromosome 4HL. Resistance to BaMMV-Teik is also encoded by rym13 or an additional gene being closer linked to rym13 than 0.65 centiMorgan (cM). Using bulked segregant analysis employing Simple sequence repeats (SSRs) and Amplified fragment length polymorphisms (AFLPs), a map comprising 39.1 cM was constructed with the closest marker linked to the BaMMV/BaMMV-Teik resistance at a distance of 1 cM. Respective markers are useful tools to introduce resistance to BaMMV-Teik into adapted breeding lines carrying other resistance genes, which are not effective against all BaMMV/BaYMV strains known in Europe, e.g. rym4, rym5.