ARS | Publication request: Saturation and comparative mapping of a major Fusarium head blight resistance QTL in tetraploid wheat

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2006
Publication Date: October 26, 2006
Citation: Chen, X., Faris, J.D., Hu, J., Stack, R.W., Adhikari, T., Elias, E.M., Kianian, S.F., Cai, X. 2006. Saturation and comparative mapping of a major Fusarium head blight resistance QTL in tetraploid wheat. Molecular Breeding. 19:113-124.

Interpretive Summary: Fusarium head blight (FHB), also known as scab, is a devastating disease of cultivated wheat worldwide. Partial resistance to FHB has been identified in common wheat. However, sources of effective FHB resistance have not been found in durum wheat. A chromosomal region harboring a major quantitative trait locus (QTL) for FHB resistance designated Qfhs.ndsu-3AS was identified on chromosome 3A of wild emmer wheat, a wild relative of durum wheat. Here, we saturated the chromosomal region containing the QTL molecular markers to further dissect the genomic region. Comparative mapping indicated that Qfhs.ndsu-3AS is not evolutionarily similar to a major FHB QTL derived from the common wheat cultivar Sumai 3. These results facilitate our efforts toward the discovery of the gene responsible for the effects of the QTL and utilization of this QTL in durum wheat breeding via marker-assisted selection.

Technical Abstract: Fusarium head blight (FHB) is a devastating disease of cultivated wheat worldwide. Partial resistance to FHB has been identified in common wheat (Triticum aestivum L.). However, sources of effective FHB resistance have not been found in durum wheat (T. turgidum L. var. durum). A major FHB resistance QTL, Qfhs.ndsu-3AS, was identified on chromosome 3A of T. dicoccoides, a wild relative of durum wheat. Here, we saturated the genomic region containing the QTL using EST-derived TRAP (target region amplified polymorphism), STS (sequence tagged site), and SSR (simple sequence repeat) markers. A total of 45 new molecular marker loci were detected on chromosome 3A and the resulting linkage map consisted of 55 markers spanning a genetic distance of 277.2 cM. Qfhs.ndsu-3AS was positioned within a chromosomal interval of 11.5 cM and is flanked by the TRAP marker loci, Xfcp401 and Xfcp397.2. The average map distance between the marker loci within this QTL region was reduced from 4.9 cM in the previous study to 3.5 cM in the present study. Comparative mapping indicated that Qfhs.ndsu-3AS is not homoeologous to Qfhs.ndsu-3BS, a major FHB QTL derived from the common wheat cultivar Sumai 3. These results facilitate our efforts toward map-based cloning of Qfhs.ndsu-3AS and utilization of this QTL in durum wheat breeding via marker-assisted selection.