title: Identification of Pm58 from Aegilops tauschii.
abstract: A novel powdery mildew-resistance gene, designated Pm58, was introgressed directly from Aegilops tauschii to hexaploid wheat, mapped to chromosome 2DS, and confirmed to be effective under field conditions. Selectable KASP™ markers were developed for MAS. Powdery mildew caused by Blumeria graminis (DC.) f. sp. tritici (Bgt) remains a significant threat to wheat (Triticum aestivum L.) production. The rapid breakdown of race-specific resistance to Bgt reinforces the need to identify novel sources of resistance. The D-genome species, Aegilops tauschii, is an excellent source of disease resistance that is transferrable to T. aestivum. The powdery mildew-resistant Ae. tauschii accession TA1662 (2n = 2x = DD) was crossed directly with the susceptible hard white wheat line KS05HW14 (2n = 6x = AABBDD) followed by backcrossing to develop a population of 96 BC2F4introgression lines (ILs). Genotyping-by-sequencing was used to develop a genome-wide genetic map that was anchored to the Ae. tauschii reference genome. A detached-leaf Bgt assay was used to screen BC2F4:6ILs, and resistance was found to segregate as a single locus (χ = 2.0, P value = 0.157). The resistance gene, referred to as Pm58, mapped to chromosome 2DS. Pm58 was evaluated under field conditions in replicated trials in 2015 and 2016. In both years, a single QTL spanning the Pm58 locus was identified that reduced powdery mildew severity and explained 21% of field variation (P value < 0.01). KASP™ assays were developed from closely linked GBS-SNP markers, a refined genetic map was developed, and four markers that cosegregate with Pm58 were identified. This novel source of powdery mildew-resistance and closely linked genetic markers will support efforts to develop wheat varieties with powdery mildew resistance.
authors.affiliation: Department of Plant, Soil and Microbial Sciences, Michigan State University, 1066 Bogue Street, Room A286, East Lansing, MI, 48824, USA.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Wiersma
authors.affiliation: Department of Plant Biology and Center for Genomics-Enabled Plant Science, Michigan State University, 612 Wilson Rd, Room 166, East Lansing, MI, 48824, USA.
authors.forename: Jane A
authors.initials: JA
authors.lastname: Pulman
authors.affiliation: Department of Plant, Soil and Microbial Sciences, Michigan State University, 1066 Bogue Street, Room A286, East Lansing, MI, 48824, USA.
authors.forename: Linda K
authors.initials: LK
authors.lastname: Brown
authors.affiliation: Department of Plant Pathology, North Carolina State University, USDA-ARS Plant Science Research, 2510 Thomas Hall, Campus Box 7616, Raleigh, NC, 27695, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Cowger
authors.affiliation: Department of Plant, Soil and Microbial Sciences, Michigan State University, 1066 Bogue Street, Room A286, East Lansing, MI, 48824, USA. eolson@msu.edu.
authors.forename: Eric L
authors.identifier: http://orcid.org/0000-0002-4527-1723
authors.initials: EL
authors.lastname: Olson
mesh_terms: D001203:Ascomycota; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D005838:Genotype; D059014:High-Throughput Nucleotide Sequencing; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D006109:Poaceae / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers