DEVELOPMENT OF SIMPLE SEQUENCE REPEAT DNA MARKERS AND THEIR INTEGRATION INTO A BARLEY LINKAGE MAP

Simple sequence repeats (SSRs), or microsatellites, are a new class of PCR-based DNA markers for genetic mapping. The objectives of the pres ent study were to develop SSR markers for barley and to integrate them into an existing barley linkage map. DNA sequences containing SSRs we re isolated from a barley genomic library and from public databases. I t is estimated that the barley genome contains one (GA)(n) repeat ever y 330 kb and one (CA)(n) repeat every 620 kb. A total of 45 SSRs were identified and mapped to seven barley chromosomes using doubled-haploi d lines and/or wheat-barley addition-line assays. Segregation analysis for 39 of these SSRs identified 40 loci. These 40 markers were placed on a barley linkage map with respect to 160 restriction fragment leng th polymorphism (RFLP) and other markers. The results of this study de monstrate the Value of SSRs as markers in genetic studies and breeding research in barley.