Production of Doubled Haploid Lines for Genetic Analysis of Useful Characters of Malting Barley

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 F 1 plants with pollen of H.bulbosum L.. Frequency of DHLs obtained was 4.5% of the pollinated fl orets. Ninety fi ve DHLs were classifi ed into 48 resistant and 47 susceptible lines in the fi eld infected with BaYMV strain I. This segregation ratio fi tted a theoretical ratio of 1:1. Segregation ratios determined with 36 molecular markers also fi tted a theoretical ratio of 1:1 except for one marker. No heterozygous genotype was observed. DHLs are useful because we could obtain fi xed lines with a completely homogeneous phenotype in a short period, and reliable repeated evaluation of phenotype is possible because they are fi xed without segregation by seed multiplication.