Abstract
To develop a DNA marker assisted selection system for lines with recessive resistance gene to all races of barley yellow mosaic virus (BaYMV), we produced doubled haploid lines (DHLs) of barley (Hordeum vulgare L.) by the bulbosum method. Japanese six-rowed barley cultivar Shimakei 6 with a gene for resistance to all races of BaYMV was crossed with susceptible two-rowed barley cultivar lk2. DHLs were obtained by pollinating the F1 plants with pollen of H.bulbosum L.. Frequency of DHLs obtained was 4.5% of the pollinated florets. Ninety five DHLs were classified into 48 resistant and 47 susceptible lines in the field infected with BaYMV strain I. This segregation ratio fitted a theoretical ratio of 1:1. Segregation ratios determined with 36 molecular markers also fitted a theoretical ratio of 1:1 except for one marker. No heterozygous genotype was observed. DHLs are useful because we could obtain fixed lines with a completely homogeneous phenotype in a short period, and reliable repeated evaluation of phenotype is possible because they are fixed without segregation by seed multiplication.
