GWAS for Stripe Rust Resistance in Wild Emmer Wheat (Triticum dicoccoides) Population: Obstacles and Solutions

Authors: TENE, MAY - Tel Aviv University; ADHIKARI, ELINA - Kansas State University; COBO, NICOLAS - University Of California, Davis; Jordan, Katherine; MATNY, OADI - University Of Minnesota; DEL BLANCO, ISABEL - University Of California, Davis; ROTER, JONATHAN - Tel Aviv University; EZRATI, SMADAR - Tel Aviv University; GOVTA, LIUBOV - University Of Haifa; MANISTERSKI, JACOB - Tel Aviv University; YEHUDA, PNINA - Tel Aviv University; Chen, Xianming; STEFFENSON, BRIAN - University Of Minnesota; AKHUNOV, EDUARD - Kansas State University; SELA, HANAN - University Of Haifa

Submitted to: Crops
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2022
Publication Date: 3/2/2022
Citation: Tene, M., Adhikari, E., Cobo, N., Jordan, K., Matny, O., Del Blanco, I.A., Roter, J., Ezrati, S., Govta, L., Manisterski, J., Yehuda, P.B., Chen, X., Steffenson, B., Akhunov, E., Sela, H. 2022. GWAS for Stripe Rust Resistance in Wild Emmer Wheat (Triticum dicoccoides) Population: Obstacles and Solutions. Crops. 2(1):42-61. https://doi.org/10.3390/crops2010005.
DOI: https://doi.org/10.3390/crops2010005

Interpretive Summary: Stripe rust is a wheat disease that causes substantial annual global yield loss. To lessen this loss, we need to develop more resistant cultivars by identifying resistance genes from wild relatives and incorporating them into elite wheat varieties. This study identified and associated naturally occurring variants in wheat’s ancestor, wild emmer, from a population in Israel that exhibit resistance to stripe rust at various stages of plant development. The strongest associations point to previously identified stripe rust resistance genes, however a potentially novel association on chromosome 3A was detected affecting seedling resistance, and additional associations were detected that enhanced resistance when coupled with resistance gene Yr36. These potential resistance genes from wild emmer provide targets that can be incorporated in wheat breeding programs to develop more resistant cultivars against stripe rust.

Technical Abstract: Stripe rust is a devastating disease in wheat that causes substantial yield loss around the world. The most effective strategy for mitigating yield loss is to develop resistant cultivars. The wild relatives of wheat are good sources of resistance to fungal pathogens. Here, we used a genome-wide association study (GWAS) to identify loci associated with stripe rust (causal agent: Puccinia striiformis f. sp. tritici) resistance in wild emmer (Triticum dicoccoides) at the seedling stage, in the greenhouse, and at the adult plant stage, in the field. We found that the two major loci contributing to resistance in our wild emmer panel were the previously cloned seedling-stage resistance gene, Yr15, and the adult-plant-stage resistance gene, Yr36. Nevertheless, we detected 12 additional minor QTLs that additionally contribute to adult plant resistance and mapped a locus on chromosome 3AS that tentatively harbors a novel seedling resistance gene. The genotype and phenotype data generated for the wild emmer panel, together with the detected SNPs associated with resistance to stripe rust, provide a valuable resource for disease-resistance breeding in durum and bread wheat.