Construction of genetic map in barley using sequence-related amplified polymorphism markers, a new molecular marker technique

Abstract

Sequence-related amplified polymorphism (SRAP) markers, a novel polymerase chain reaction (PCR)-based molecular marker technique, were successfully applied in map construction, cultivar identification, diversity evaluation, comparative genomics and gene location of different plant species. The molecular genetic map of SRAP markers in Steptoe / Morex doubled haploid (DH) population was constructed in this study, using 216 SRAP markers and 312 simple sequence repeat (SSR) markers. Overall, 21 of the 216 SRAP markers generated 78 polymorphic loci, and 98 of 312 SSR markers produced 107 polymorphic loci. Among the 185 loci, 175 loci (70 SRAP loci and 105 SSR loci) were assigned to nine linkage groups. The map covered 1475 cM with a mean density of 8.7 cM per locus. In total, 33 of all the loci (17.84%) showed significant segregation distortion. Moreover, 23 of the 33 loci (69.7%) skewed towards the parent Steptoe, whereas the remaining loci (21.3%) deviated towards the parent Morex and some of these distorted loci tended to cluster at the end of linkage groups, while others were dispersed on linkage groups in a decentralized fashion. The three putative segregation distortion regions (SDRs) were detected on chromosomes 2H, 4H and 5H, respectively. This linkage map indicates its importance in quantitative trait loci (QTLs) mapping, marker-assisted selection (MAS) and integrative analysis for further genetic studies with other linkage maps in barley.

Keywords: Barley, sequence-related amplified polymorphism (SRAP), molecular genetic map, simple sequence repeat (SSR), doubled haploid (DH) population