Location: Hard Winter Wheat Genetics ResearchTitle: Reassigning Hessian fly resistance genes H7 and H8 to chromosomes 6A and 2B of the wheat cultivar ‘Seneca’ using genotyping-by-sequencing
|LIU, GUOXIA - Kansas State University|
|XU, YUNFENG - Kansas State University|
|LI, YAOGUANG - Kansas State University|
|FUAN, NIU - Kansas State University|
|ZHAO, LANFEI - Kansas State University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2020
Publication Date: N/A
Interpretive Summary: Hessian fly (HF) is a destructive insect pest of wheat that causes stunting and lodging. Wheat cultivar ‘Seneca’ was reported to carry Hessian fly resistance genes H7 on chromosome 5D and H8, which had an unknown chromosome location. This study used a genetic map of 1,911 DNA markers to locate the genes for HF resistance in a population from the cross of cultivar 'Bobwhite' x Seneca. We reassigned H7 to chromosome 6A, thus correcting an old error in the literature. H8 was mapped to chromosome 2B. H7 showed a major effect, but H8 had only a minor effect on resistance. DNA markers linked to H7 were developed for marker-assisted selection of H7 by wheat breeders.
Technical Abstract: Hessian fly (HF), Mayetiola destructor, is a destructive insect pest in most wheat (Triticum aestivum L.) growing areas worldwide. Growing resistant cultivars can effectively reduce the HF damage. Wheat cultivar ‘Seneca’ was reported to carry resistance genes H7 on chromosome 5D and H8 with unknown location. To further validate the resistance gene locations in Seneca, a recombinant inbred line (RIL) population from Bobwhite x Seneca was genotyped using 3,330 single nucleotide polymorphism (SNP) markers generated from genotyping-by-sequencing (GBS), and phenotyped for HF resistance in the greenhouse experiments. Phenotypic analyses showed at least two genes conditioning HF resistance in Seneca, but none of them was mapped on chromosome 5D as previously reported. Instead, one major gene, designated as H7, was mapped to chromosome 6A and explained 60.7 - 78.3% of the phenotypic variation. The other gene with a minor effect, designated as H8, was found on chromosome 2B and explained 3.2-4.7% of the phenotypic variation. Based on the physical locations of flanking markers for H7 in Chinese Spring reference genome, H7 was located in a 6 Mb interval on 6AL. This study reassigned the major gene H7 to chromosome 6A and the minor gene H8 to 2B in Seneca using a high-density SNP map. Seventeen GBS-SNPs mapped in H7 region were converted into Kompetitive Allele Specific Polymerase Chain Reaction (KASP) markers for selecting this gene in breeding.