Quantitative Trait Loci Conditioning Resistance to Fusarium Head Blight in Wheat Line F201R

Abstract

Fusarium head blight (FHB) of wheat (Triticum aestivum L.) is a devastating disease in wheat production worldwide. Identifying resistance genes and understanding the genetic basis of resistance to FHB are prerequisites to developing cultivars that can avoid losses from FHB. This investigation of quantitative trait loci (QTL) was performed in a recombinant inbred (RI) population derived from a cross between the FHB-moderately susceptible cv. Patterson and the FHB-resistant line Fundulea 201R (F201R). Bulk DNAs from the 11 most resistant and 12 most susceptible lines of the phenotypic distribution of the RI population, together with the parental lines, were screened with simple sequence repeat (SSR) markers. Regional QTL mapping identified four interval regions, located on chromosomes 1B, 3A, 3D, and 5A, that conferred resistance to FHB. The QTLs located on chromosomes 1B and 3A, contributed by F201R, had large effects and were consistently expressed in three environments. The four QTLs together accounted for 32.7% of the phenotypic variation, or 43.0% of the genotypic variation. The QTL on chromosome 3A is located in the same region as a QTL that was detected in wild tetraploid wheat T. dicoccoides (Koern. ex Asch. & Graebner) Aarons. The possibility that the FHB resistance QTLs of F201R and that of T. dicoccoides on chromosome 3A have the same origin is discussed.