Microsatellite mapping of the induced sphaerococcoid mutation genes in Triticum aestivum

Abstract 

The S1, S2 and S3 genes of the induced sphaerococcoid mutation in common wheat (Triticum aestivum) were mapped using three different F₂ populations consisting of 71–96 individual plants. Twenty-four microsatellite markers from homeologous group 3 of T. aestivum were used to map the S1, S2 and S3 genes on chromosomes 3D, 3B and 3A, respectively. The S1 locus was found to be closely linked to the centromeric marker Xgwm456 of the long arm (2.9 cM) and mapped not far (8.0 cM) from the Xgdm72 marker of the short arm of chromosome 3D. The S2 gene was tightly linked to 2 centromeric markers (Xgwm566, Xgwm845) of chromosome 3B. S3 was located between Xgwm2 (5.1 cM), the marker of the short arm, and Xgwm720 (6.6 cM), the marker of the long arm, both of chromosome 3A. Mapping the S1, S2 and S3 loci of the induced sphaerococcoid mutation near the centromeric regions supports the hypothesis that the sphaerococcum type may be due to gene duplication resulting from DNA recombination in the centromeric region.