Molecular Mapping of QTL for a Transformation‐Related Trait and FHB Resistance in a Recombinant Inbred Population of Bobwhite × PI 277012

ABSTRACT Bobwhite is one of the wheat cultivars that have been widely used for wheat transformation, but the genetic mechanism underlying its high transformability is not understood. To identify quantitative trait loci (QTL) associated with plant regeneration capability (PRC) in Bobwhite, a mapping population of 186 recombinant inbred lines (RILs) was developed from the cross between Bobwhite and PI 277012, a wheat accession exhibiting high resistance to Fusarium head blight (FHB) but low PRC. Immature embryos were used as explants for tissue culture to induce calli, and plant regeneration rates from the calli were recorded for the parents and RILs. The average regeneration rate was 0% and 42.5% for PI 277012 and Bobwhite, respectively. The RILs had an average regeneration rate ranging from 0% to 33%. Using a genotyping‐by‐sequencing approach, a genetic linkage map was constructed with 3779 single nucleotide polymorphism (SNP) markers distributed on all 21 chromosomes, spanning 2291 cM. QTL analysis detected two QTL controlling PRC in Bobwhite, which were mapped on chromosomes 1A ( Qprc.ndwp‐1A ) and 6D ( Qprc.ndwp‐6D ) and accounted for 10.5% and 9.8% of the phenotypic variation, respectively. To confirm the FHB resistance QTL ( Qfhb.rwg‐5A.1 and Qfhb.rwg‐5A.2 ) previously identified in PI 277012, the RIL population was also phenotyped for FHB resistance in greenhouse (GH) and field experiments. However, only one QTL overlapping with Qfhb.rwg‐5A.2 on chromosome 5AL was identified from PI 277012 in this population, which explained 36.2% and 33.0% of the phenotypic variance for FHB resistance under the GH and field environments, respectively. The information from this study may facilitate the transfer of the transformability QTL into other wheat varieties that are difficult to transform. This study also confirmed that Qfhb.rwg‐5A.2 in PI 277012 is a major QTL for FHB resistance stably expressed in different genetic backgrounds.