An international wheat diversity panel reveals novel sources of genetic resistance to tan spot in Australia

Authors

Julian Taylor, University of Adelaide
Dorthe Jorgensen, Department of Primary Industries and Regional Development, Western AustraliaFollow
Caroline S. Moffat, Curtin University of Technology
Ken J. Chalmers, University of Adelaide
Rebecca Fox, University of Adelaide
Grant J. Hollaway, Agriculture Victoria
Melissa J. Cook, Agriculture Victoria
Stephen M. Neate, University of Southern Queensland
Pao Theen See, Curtin University of Technology
Manisha Shankar, Department of Primary Industries and Regional Development, Western AustraliaFollow

Document Type

Article

Publication Date

3-13-2023

Journal Title

Theoretical and Applied Genetics

ISSN

Print: 0040-5752 Electronic: 1432-2242

Disciplines

Agronomy and Crop Sciences | Biosecurity | Plant Breeding and Genetics

Abstract

Tan spot is a foliar disease in wheat caused by the fungal pathogen Pyrenophora tritici-repentis (Ptr) and has been reported to generate up to 50% yield losses under favourable disease conditions. Although farming management practices are available to reduce disease, the most economically sustainable approach is establishing genetic resistance through plant breeding. To further understand the genetic basis for disease resistance, we conducted a phenotypic and genetic analysis study using an international diversity panel of 192 wheat lines from the Maize and Wheat Improvement Centre (CIMMYT), the International Centre for Agriculture in the Dry Areas (ICARDA) and Australian (AUS) wheat research programmes. The panel was evaluated using Australian Ptr isolates in 12 experiments conducted in three Australian locations over two years, with assessment for tan spot symptoms at various plant development stages. Phenotypic modelling indicated high heritability for nearly all tan spot traits with ICARDA lines displaying the greatest average resistance. We then conducted a one-step whole-genome analysis of each trait using a high-density SNP array, revealing a large number of highly significant QTL exhibiting a distinct lack of repeatability across the traits. To better summarise the genetic resistance of the lines, a one-step genomic prediction of each tan spot trait was conducted by combining the additive and non-additive predicted genetic effects of the lines. This revealed multiple CIMMYT lines with broad genetic resistance across the developmental stages of the plant which can be utilised in Australian wheat breeding programmes to improve tan spot disease resistance.

Recommended Citation

Taylor, J., Jorgensen, D., Moffat, C.S. et al. An international wheat diversity panel reveals novel sources of genetic resistance to tan spot in Australia. Theor Appl Genet 136, 61 (2023). https://doi.org/10.1007/s00122-023-04332-y