Abstract: A diploid barley cultivar "Supi 1" was crossed with a tetraploid Hordeum bulbosum “GBC141” to transfer the disease resistant traits. Eleven viable triploid F1 plants were produced by means of embryo rescue technique. The resulting triploid hybrids were backcrossed to diploid barley, and seven BC1 plants were obtained. One of the BC1 plants exhibited barley yellow mosaic virus (BaYMV) resistance when grown in the diseased nursery. Isozyme analysis of H. vulgate, H. bulbosum and their backcross hybrids were made via slab polyacrylamide gel electrophoresis technique. The primary results showed that zymogram variation could be obviously found between diploid barley "Supi 1' and tetraploid H. bulbosurn "GBC141”. A peroxidase isozyme (Rf=0.47) from H. bulbosum was detected in the peroxidase isozyme zymogram of young roots of backcross hybrid BC1-2. This peroxidase isozyme was related to the BaYMV resistance but the linkage relation will be determined by the genetic analysis of the F2 population in the future. The BaYMV resistant line of the backcross with isozyme marker is the important resource of barley disease-resistant breeding.

Key words: Hordeum bulbosum, Barley yellow mosaic virus, Peroxidase isozyme, Isozymic marker