Identification of two QTL for Hessian fly resistance in a Pakistan spring wheat cultivar Parvaz-94

Hessian fly (HF), Mayetiola destructor (Say), is a serious pest of wheat (Triticum aestivum L.) worldwide. Growing resistant cultivars is the most effective and economical approach for HF management. Previous screening of 176 wheat accessions from Pakistan only identified Parvaz-94 with high resistance to HF biotype Great Plains (GP), a predominant biotype in the US Great Plains. To determine the quantitative trait loci (QTL) for HF resistance in Parvaz-94, we evaluated a population of 178 recombinant inbred lines from Parvaz-94 × Cadenza for resistance to HF biotype GP and constructed a high-density linkage map with 3469 single-nucleotide polymorphisms generated by genotyping-by-sequencing. Two QTLs (QHf.hwwg-1AS.2 and QHf.hwwg-6BS.2) were identified on the short arms of chromosomes 1A and 6B, respectively. QHf.hwwg-1AS.2 was mapped to a 4.0 Mb interval (4.6–8.6 Mb) on the chromosome arm 1AS, and QHf.hwwg-6BS.2 was localized to a 5.4 Mb interval (2.3–7.7 Mb) on the chromosome arm 6BS based on International Wheat Genome Sequencing Consortium RefSeq v2.1 reference genome. Kompetitive allele-specific PCR markers were developed for both QTL. The marker K6B_7697506, tightly linked to QHf.hwwg-6BS.2, was validated in three diversity panels of 610 winter wheat accessions from the major US winter wheat growing states and can be used for marker-assisted selection of QHf.hwwg-6BS.2 in breeding programs.