Development, chromosome location and genetic mapping of EST-SSR markers in wheat

A number of 151695 wheat expression sequence tags (ESTs) that originated from GenBank/dbEST from July 14, 2003 to August 24, 2004 were used to search for simple sequence repeats (SSRs) with motif 2―5 bp, and 2038 simple sequence repeats (EST-SSRs), which accounted for 1.34% of EST database, were identified. Based on these SSR sequences, 249 EST-SSR primer pairs and 166 amplified clear bands in various wheat cultivars were designed. These EST-SSR markers can be used as new molecular markers in wheat and related species. Using Chinese Spring nulli-tetrasomic lines, 93 EST-SSR primer pairs and 193 EST-SSR loci were located on 19 wheat chromosomes except for 4A and 4B. Forty-three loci were mapped on 11 chromosomes of the genetic frame- work map previously constructed using recombinant inbred lines.