The physical mapping of microsatellite markers in wheat

Microsatellite markers represent a new class of genetic markers in plants. Such markers reveal a high level of polymorphism even in species with a narrow genetic base, such as hexaploid wheat (Triticum aestivum L.). We used a large set of such markers and 25 deletion stocks of 'Chinese Spring' in a deletion-mapping experiment to study the physical distribution of dinucleotide microsatellite markers in homoeologous group 2 chromosomes of hexaploid wheat. Thirty-one microsatellite markers identified 14 loci in chromosome 2A, 9 loci in chromosome 2B, and 10 loci in chromosome 2D. The microsatellite loci were evenly distributed along the chromosome length, marking 18 of 27 defined physical intervals, including centromeric, interstitial, and telomeric regions. The apparent random distribution indicates that microsatellite markers provide excellent coverage of the wheat genome.