A Microsatellite Map of Wheat

TLDR

Hexaploid bread wheat (Triticum aestivum L.) is one of the world’s most important crop plants and exhibits very low intraspecific polymorphism. The study aims to develop highly polymorphic microsatellite markers optimized for the large wheat genome. The authors amplified 279 loci with 230 primer sets and mapped them onto a genetic framework using RFLPs from the ITMI reference population. The resulting markers are 80 % genome‑specific, 20 % multi‑locus, with 65 microsatellites mapped at LOD > 2.5, 214 assigned to intervals, and distributed across the A, B, and D genomes with centromeric clustering. Abstract: Hexaploid bread wheat (Triticum aestivum L.) is a major crop.

Abstract

Abstract Hexaploid bread wheat (Triticum aestivum L. em. Thell) is one of the world's most important crop plants and displays a very low level of intraspecific polymorphism. We report the development of highly polymorphic microsatellite markers using procedures optimized for the large wheat genome. The isolation of microsatellite-containing clones from hypomethylated regions of the wheat genome increased the proportion of useful markers almost twofold. The majority (80%) of primer sets developed are genome-specific and detect only a single locus in one of the three genomes of bread wheat (A, B, or D). Only 20% of the markers detect more than one locus. A total of 279 loci amplified by 230 primer sets were placed onto a genetic framework map composed of RFLPs previously mapped in the reference population of the International Triticeae Mapping Initiative (ITMI) Opata 85 × W7984. Sixty-five microsatellites were mapped at a LOD >2.5, and 214 microsatellites were assigned to the most likely intervals. Ninety-three loci were mapped to the A genome, 115 to the B genome, and 71 to the D genome. The markers are randomly distributed along the linkage map, with clustering in several centromeric regions.