Wheat genetic loci conferring resistance to stripe rust in the face of genetically diverse races of the fungus Puccinia striiformis f. sp. tritici

• Published in: Theoretical and applied genetics Vol. 135; no. 1; pp. 301 - 319
• Main Authors: Bouvet, Laura, Percival-Alwyn, Lawrence, Berry, Simon, Fenwick, Paul, Mantello, Camila Campos, Sharma, Rajiv, Holdgate, Sarah, Mackay, Ian J., Cockram, James
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-01-2022; Springer; Springer Nature B.V
• Subjects: Agricultural research; Agriculture; Alleles; Biochemistry; Biomedical and Life Sciences; Biotechnology; Development and progression; Disease resistance; Disease Resistance - genetics; Gene loci; Gene polymorphism; Genetic analysis; Genetic aspects; Genetic markers; Genotype; Haplotypes; Life Sciences; Original; Original Article; Phenotypic variations; Physiological aspects; Plant Biochemistry; Plant breeding; Plant Breeding/Biotechnology; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Genetics and Genomics; Plant immunology; Plant-pathogen relationships; Polymorphism, Single Nucleotide; Puccinia - immunology; Puccinia - physiology; Puccinia striiformis; Quantitative Trait Loci; Races; Risk factors; Rust diseases; Single-nucleotide polymorphism; Stripe rust; Triticum - genetics; Triticum - immunology; Triticum - microbiology; Triticum aestivum; Wheat; United Kingdom
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-021-03967-z

Key message
Analysis of a wheat multi-founder population identified 14 yellow rust resistance QTL. For three of the four most significant QTL, haplotype analysis indicated resistance alleles were rare in European wheat.
Stripe rust, or yellow rust (YR), is a major fungal disease of wheat (
Triticum aestivum
) caused by
Puccinia striiformis
Westend f. sp.
tritici
(
Pst
). Since 2011, the historically clonal European
Pst
races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties previously showing durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map YR resistance to such new
Pst
races. Genetic analysis of five field trials at three UK sites identified 14 quantitative trait loci (QTL) conferring resistance. Of these, four highly significant loci were consistently identified across all test environments, located on chromosomes 1A (
QYr.niab-1A.1
), 2A (
QYr.niab-2A.1
), 2B (
QYr.niab-2B.1
) and 2D (
QYr.niab-2D.1
), together explaining ~ 50% of the phenotypic variation. Analysis of these four QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL, and genetic markers were developed that distinguished resistant and susceptible alleles. Haplotype analysis in a collection of wheat varieties found that the haplotypes associated with YR resistance at three of these four major loci were rare (≤ 7%) in European wheat, highlighting their potential utility for future targeted improvement of disease resistance. Notably, the physical interval for QTL
QYr.niab-2B.1
contained five nucleotide-binding leucine-rich repeat candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes
Yr7
and
Yr5/YrSp
.
Graphical abstract