Toward a better understanding of the genomic region harboring Fusarium head blight resistance QTL Qfhs.ndsu-3AS in durum wheat

Abstract

New molecular markers were developed and mapped to the FHB resistance QTL region in high resolution. Micro-collinearity of the QTL region with rice and Brachypodium was revealed for a better understanding of the genomic region. The wild emmer wheat (Triticum dicoccoides)-derived Fusarium head blight (FHB) resistance quantitative trait locus (QTL) Qfhs.ndsu-3AS previously mapped to the short arm of chromosome 3A (3AS) in a population of recombinant inbred chromosome lines (RICLs). This study aimed to attain a better understanding of the genomic region harboring Qfhs.ndsu-3AS and to improve the utility of the QTL in wheat breeding. Micro-collinearity of the QTL region with rice chromosome 1 and Brachypodium chromosome 2 was identified and used for marker development in saturation mapping. A total of 42 new EST-derived sequence tagged site (STS) and simple sequence repeat (SSR) markers were developed and mapped to the QTL and nearby regions on 3AS. Further comparative analysis revealed a complex collinearity of the 3AS genomic region with their collinear counterparts of rice and Brachypodium. Fine mapping of the QTL region resolved five co-segregating markers (Xwgc1186/Xwgc716/Xwgc1143/Xwgc501/Xwgc1204) into three distinct loci proximal to Xgwm2, a marker previously reported to be closely linked to the QTL. Four other markers (Xwgc1226, Xwgc510, Xwgc1296, and Xwgc1301) mapped farther proximal to the above markers in the QTL region with a higher resolution. Five homozygous recombinants with shortened T. dicoccoides chromosomal segments in the QTL region were recovered by molecular marker analysis and evaluated for FHB resistance. Qfhs.ndsu-3AS was positioned to a 5.2 cM interval flanked by the marker Xwgc501 and Xwgc510. The recombinants containing Qfhs.ndsu-3AS and new markers defining the QTL will facilitate utilization of this resistance source in wheat breeding.

Breeding strategies and advances in line selection for Fusarium head blight resistance in wheat

“…More distantly related wild and cultivated relatives, e.g. T. dicoccoides, T. dicoccum and T. carthlicum, were screened to broaden the base of resistant sources for durum wheat (2003a, 2003aOliver et al 2007Oliver et al , 2008, but resistances found therein do not come close to the strong QTL detected in hexaploid wheat (Prat et al 2014;Zhang et al 2014;Zhu et al 2016b). …”

“…The authors demonstrate that the gene does not confer resistance against DON suggesting that toxin resistance is under different genetic control in the same genetic block (Rawat et al 2016). For several other resistance QTL fine-mapping and cloning approaches are underway, which will result in the development of diagnostic markers for resistance QTL to be easily adopted by breeders (Cuthbert et al 2007;Xue et al 2010Xue et al , 2011Zhu et al 2016b). …”

QTL mapping of Fusarium head blight resistance in three related durum wheat populations

“…Hermon#22, and Mt. Gerizim#36 have been identified on chromosomes 3A (Otto et al 2002; Gladysz et al 2007; Chen et al 2007; Buerstmayr et al 2013; Zhu et al 2016b), 4A (Gladysz et al 2007), 6B (Buerstmayr et al 2013) and 7A (Kumar et al 2007). Triticum dicoccum accessions PI 41025, Td-161 and BGRC3487 provided resistance QTL on 3A, 3B, 4B, 5A, 6A, 6B, 7A and 7B (Buerstmayr et al 2012; Ruan et al 2012; Zhang et al 2014).…”

A valuable QTL for Fusarium head blight resistance from Triticum turgidum L. ssp. dicoccoides has a stable expression in durum wheat cultivars

“…New markers closer to Qfhs. ndsu-3AS have recently become available (Zhu et al 2015). Within MM and Mm progeny, all except for three plants (one MM and two Mm plants from B. Esmeralda × Langdon(Dic-3A)-10 cross) exhibited lower disease scores than the resistant parent (data not shown).…”

“…Mapping analysis positioned Qfhs.ndsu-3AS within a chromosomal interval of 11.5 cM that is flanked by markers Xfcp401 and Xfcp397.2, with the microsatellite locus Xgwm2 tightly linked to Qfhs.ndsu-3A (Chen et al 2007). A recent study saturated the Qfhs.ndsu-3AS region using 22 newly EST-derived markers (Zhu et al 2015).…”