Oral Presentation Australasian Plant Pathology Society Conference 2025

The CIMMYT Australia ICARDA Evaluation Contribution to Identify Adapted High-Yielding Wheat Lines with Genetic Resistance to Multiple Pathogens of Economic Importance to the Australian Grain Growing Regions (123538)

Laura Ruiz Espinosa 1 , Julie Nicol 1 , Amit Kumar Singh 1 , Mark Dieters 2 , Robert Park 1 , Davinder Singh 1 , Laura Ziems 1 , Manisha Shankar 3 , Andrew Milgate 4 , Grant Hollaway 5 , Melissa Cook 5 , Hari Dadu 5 , Jason Sheedy 6 , Tara Garrard 7 , Hugh Wallwork 7 , Lisle Snyman 8 , Susanne Dreisigacker 9 , Velu Govindan 9 , Ravi P. Singh 9 , Abdelfattah A. Dababat 9 10 , Wuletaw Tadesse 11 , Sally Norton 12 , Nick Fradgley 13 , Vivi Arief 14 , Robin Wilson 15
  1. The University of Sydney, Cobbitty, NSW, Australia
  2. The University of Queensland, Brisbane, Queensland, Australia
  3. Department of Primary Industries and Regional Development, South Perth, WA, Australia
  4. NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, Australia
  5. Agriculture Victoria, Horsham, Victoria, Australia
  6. University of Southern Queensland, Toowoomba, NSW, Australia
  7. South Australin Research and Development Institute, Waite Campus, Urrbrae, SA, Australia
  8. Department of Primary Industries, Warwick, Queensland, Australia
  9. International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Mexico
  10. International Maize and Wheat Improvement Center (CIMMYT), Ankara, Turkey
  11. International Center for Agricultural Research in the Dry Areas (ICARDA), Rabat, Morocco
  12. Australian Grains Genebank, Agriculture Victoria, Horsham, Victoria, Australia
  13. CSIRO Agriculture and Food, Canberra, ACT, Australia
  14. School of Agriculture and Food Sustainability, University of Queensland, St. Lucia, Queensland, Australia
  15. Integrated Breeding Platform, Perth, WA, Australia

Genetic diversity is key to breeding new varieties with pathogen resistance (ability of the plant to reduce multiplication in the presence of the pathogen) and tolerance (ability of the plant to maintain its yield despite attack of the pathogen), along with agronomic traits for grain yield and quality. Meanwhile, the development and severity of crop diseases also depend on environmental conditions and management.

 

The CIMMYT, Australia and ICARDA Germplasm Evaluation (CAIGE) project has been instrumental in providing genetic diversity for both, yield and disease resistance/tolerance for bread wheat (Triticum aestivum), durum wheat (T. durum) and barley (Hordeum vulgare) in collaboration with Australian and international partners from the Consultative Group on International Agricultural Research (CGIAR) since 2006.  CAIGE is funded by the Grains Research Development Corporation (GRDC) and has made a significant economic contribution to the Australian grain industry, with a recent proven 20:1 cost benefit analysis (Trethowan et al., 2024).  In collaboration with public and private research and breeding organizations, selected lines are imported, quarantined, multiplied, genotyped using the Infinium Wheat Barley 40K SNP array (Keeble-Gagnère et al., 2021), distributed and tested for yield and disease resistance in multiple-environment trials across the three main Australian cereal growing regions (North, South and West).

 

Between 2022-2024, 863 bread wheat lines were screened by pathologists for stripe/yellow rust (caused by Puccinia striiformis f. sp. tritici), leaf rust (P. triticina) and stem rust (P. graminis f. sp. tritici), septoria blotch (both Zymoseptoria tritici and Parastagonospora nodorum) and yellow spot/tan spot/yellow leaf spot (Pyrenophora tritici-repentis). A portion of these lines was also assessed for the root diseases crown rot (Fusarium pseudograminearum) and root-lesion nematode (RLN; Pratylenchus thornei), with resistance and tolerance evaluated for RLN only.  Rolling 3-year multi-environment trial analyses were conducted using both genotypic data and pedigree information (coefficient of parentage) to partition additive and non-additive genetic effects for yield adaptation. The Breeding Management System (BMS) platform enables the processing and delivery of results and insights from these analyses to collaborating breeding industry partners, ensuring impact.

 

Most of the CAIGE material showed some level of resistance to all three rusts. Resistance for either crown rot or septoria was less common, but still present and useful. Several CAIGE lines with multiple disease resistance have also been identified against foliar diseases (rust, septoria nodorum blotch, tan spot and powdery mildew), as well as root diseases (RLN and crown rot). Providing these resistances in well-adapted wheat backgrounds has enabled several CAIGE lines to be released directly as varieties or used as elite parents by plant breeders.

  1. KEEBLE-GAGNÈRE, G., PASAM, R., FORREST, K. L., WONG, D., ROBINSON, H., GODOY, J., RATTEY, A., MOODY, D., MULLAN, D., WALMSLEY, T., DAETWYLER, H. D., TIBBITS, J. & HAYDEN, M. J. 2021. Novel Design of Imputation-Enabled SNP Arrays for Breeding and Research Applications Supporting Multi-Species Hybridization. Frontiers in Plant Science, Volume 12 - 2021.
  2. TRETHOWAN, R. M., NICOL, J. M., SINGH, A., SINGH, R. P., TADESSE, W., GOVIDAN, V., CRESPO-HERRERA, L., CULLIS, B., MAZUR, L., DIETERS, M., MICALLEF, S., FARRELL, T., WILSON, R. & MATHEWS, K. 2024. The CIMMYT Australia ICARDA Germplasm Evaluation concept: a model for international cooperation and impact. Frontiers in Plant Science, 15.