Dissecting multi-rust resistance in wheat through genome-wide association study, haplotype analysis, and marker...

Area of Science:

• Plant genetics
• Agricultural science
• Crop pathology

Background:

• Wheat is a staple food crop susceptible to significant yield losses from leaf rust (LR), stem rust (SR), and stripe rust (YR).
• Developing wheat genotypes with broad-spectrum resistance to multiple rust pathotypes is a critical challenge for global food security.

Purpose of the Study:

• To investigate the genomic underpinnings of resistance to LR, SR, and YR in a diverse panel of bread wheat (Triticum aestivum).
• To identify genetic markers and candidate genes associated with multiple rust resistance (MRR) for accelerated breeding programs.

Main Methods:

• Phenotypic evaluation of 346 wheat accessions over two years against prevalent rust pathotypes.
• Genotyping using the 35K Axiom Wheat Breeders Array to obtain 11,910 high-quality single nucleotide polymorphisms (SNPs).
• Genome-wide association studies (GWAS) and haplotype analysis to identify significant SNPs and superior haplotypes for MRR.

Main Results:

• Eleven significant SNPs associated with 47 disease resistance genes were identified on chromosomes 3A, 3B, 3D, and 7B.
• Two haplotypes (H006 and H007) demonstrated superior performance for multiple rust resistance.
• Seventeen elite accessions with high MRR potential were selected, and three validated Kompetitive allele specific polymerase chain reaction (KASP) markers were developed.

Conclusions:

• An integrated genomic approach effectively identified genetic factors conferring resistance to major wheat rust diseases.
• The identified SNPs, genes, and markers can accelerate the breeding of wheat cultivars with durable, broad-spectrum resistance to rusts.