Targeted Discovery of Single‐Nucleotide Polymorphisms in an Unmarked Wheat Chromosomal Region Containing the Hessian Fly Resistance Gene H33

Abstract

The durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] Hessian fly [Mayetiola destructor (Say)] resistance gene H33 was previously introgressed into common wheat (T. aestivum L.) and mapped to chromosome 3AS. However, H33 located to a region that is known to be devoid of molecular markers, with the closest flanking simple‐sequence repeat (SSR) markers 7.4 and 25.1 cM from the gene. This lack of markers flanking economically important genes is a common problem in self‐pollinating crops because of low polymorphism and, in the case of wheat, a large genome size. H33 is currently effective against all virulent Hessian fly populations tested from the southeastern United States, a region where deployed resistance genes are beginning to fail; thus, effort was needed to identify tightly linked flanking markers to use this valuable gene in marker‐assisted selection (MAS). To target the 25.1‐cM segment adjacent to H33 for marker discovery, eight resistant and four susceptible plants were selected for genotyping‐by‐sequencing (GBS). Four single‐nucleotide polymorphisms (SNPs) were identified, with the closest marker being only 6.7 cM away and converted into high‐throughput polymerase chain reaction (PCR)‐based markers for the Kompetitive Allele Specific PCR (KASP) assay. In addition, endonucleases were identified that cut at the SNPs for restriction profiling as an alternate to the KASP assay. Development of these cost‐effective markers provided both low‐ and high‐throughput alternatives for introgressing H33 into wheat cultivars while minimizing linkage drag associated with durum regions of chromosome 3AS.

Multiple molecular defense strategies in Brachypodium distachyon surmount Hessian fly (Mayetiola destructor) larvae-induced susceptibility for plant survival

“…Deployment of Hessian fly resistance ( H ) genes is the most effective way to manage this insect pest. To date 35 H (H1 to H34 plus Hdic ) genes have been identified 13–15 . However, the use of H gene resistance results in the selection of Hessian fly biotypes that can overcome deployed resistance posing a great challenge to the long-term protection of wheat.…”

Phenotypic and molecular characterization of Hessian fly resistance in diploid wheat, Aegilops tauschii

“…The wheat-Hessian fly interaction fits the gene-for-gene model with the recognition of the larval avirulence gene product by the host-resistance product [5]. The most effective, and economical way to manage this insect pest is by deploying resistant wheat cultivars harboring Hessian fly resistance ( H ) genes [2, 6], with 35 genes ( H1 to H34 plus Hdic ) being documented so far [7–9]. However, deployment of resistant cultivars with high level of antibiosis to the larvae exerts strong selection pressure on Hessian fly populations, favoring the selection of virulent biotypes [10] that can overcome deployed resistance, posing a threat to long-term production of wheat.…”

Registration of durum wheat (Triticum turgidum ssp. durum) sources of resistance to Hessian fly

“…‘Len’ (CItr 17790), a known susceptible hexaploid accession (Kong, Cambron, & Ohm, 2008), was included as a susceptible check. Similarly, one known resistant tetraploid accession (PI 134942), which is the donor of H33 (McDonald et al., 2014; Subramanyam, Nemacheck, Xiao, McDonald, & Williams, 2016), was included as a resistant check. Besides, four durum wheat lines (CItr 15329, CItr 15330, CItr 15331, and CItr 15332) from North Dakota State University were added to the test.…”