title: QTL mapping identifies a major locus for resistance in wheat to Sunn pest (Eurygaster integriceps) feeding at the vegetative growth stage.
abstract: This research provides the first report of a major locus controlling wheat resistance to Sunn pest. It developed and validated SNP markers that will be useful for marker-assisted selection. Sunn pest (Eurygaster integriceps Puton) is the most destructive insect pest of bread wheat and durum wheat in West and Central Asia and East Europe. Breeding for resistance at the vegetative stage of growth is vital in reducing the damage caused by overwintered adult populations that feed on shoot and leaves of seedlings, and in reducing the next generation of pest populations (nymphs and adults), which can cause damage to grain quality by feeding on spikes. In the present study, two doubled haploid (DH) populations involving resistant landraces from Afghanistan were genotyped with the 90k SNP iSelect assay and candidate gene-based KASP markers. The DH lines and parents were phenotyped for resistance to Sunn pest feeding, using artificial infestation cages at Terbol station, in Lebanon, over three years. Quantitative trait locus (QTL) analysis identified a single major locus on chromosome 4BS in the two populations, with the resistance allele derived from the landrace accessions, IG139431 and IG139883. The QTL explained a maximum of 42 % of the phenotypic variation in the Cham6 × IG139431 and 56 % in the Cham6 × IG139883 populations. SNP markers closest to the QTL showed high similarity to rice genes that putatively encode proteins for defense response to herbivory and wounding. The markers were validated in a large, unrelated population of parental wheat genotypes. All wheat lines carrying the 'C-G' haplotype at the identified SNPs were resistant, suggesting that selection based on a haplotype of favourable alleles would be effective in predicting resistance status of unknown genotypes.
authors.affiliation: Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, 2650, Australia. livinus.emebiri@dpi.nsw.gov.au.
authors.forename: L C
authors.initials: LC
authors.lastname: Emebiri
authors.affiliation: NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle NSW, Menangle, NSW, 2568, Australia.
authors.forename: M-K
authors.initials: MK
authors.lastname: Tan
authors.affiliation: The International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat Instituts, P. O. Box 6299, Rabat, Morocco.
authors.forename: M
authors.initials: M
authors.lastname: El-Bouhssini
authors.affiliation: NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle NSW, Menangle, NSW, 2568, Australia.
authors.forename: O
authors.initials: O
authors.lastname: Wildman
authors.affiliation: The International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat Instituts, P. O. Box 6299, Rabat, Morocco.
authors.forename: A
authors.initials: A
authors.lastname: Jighly
authors.affiliation: The International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat Instituts, P. O. Box 6299, Rabat, Morocco.
authors.forename: W
authors.initials: W
authors.lastname: Tadesse
authors.affiliation: The International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat Instituts, P. O. Box 6299, Rabat, Morocco.|Grains Research and Development Corporation, P. O. Box 5367, Kingston, ACT, 2604, Australia.
authors.forename: F C
authors.initials: FC
authors.lastname: Ogbonnaya
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D008040:Genetic Linkage; D005819:Genetic Markers; D005828:Genetics, Population; D005838:Genotype; D006238:Haploidy; D060434:Herbivory; D007313:Insecta; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D014908:Triticum / Q000235:genetics*
chemical_list: D005819:Genetic Markers