Key points

• With growing consumer demand, oats have potential to become a more important and profitable crop for Australian growers
• New sources of oat disease resistance will contribute to reducing the crop’s in-season risk

While there are dedicated oat growers in Australia, the crop typically plays a minor role as a break option. Total plantings are about five per cent of the annual grain crop.

However, increasing demand from consumers recognising the health benefits associated with consumption of wholegrain oats and oat-derived products is leading to improved economic returns to growers and an increase in the area sown to the crop.

Oats can be more tolerant of adverse growing conditions, potentially providing a low-risk opportunity to reduce weed and disease pressure. Investment in oat disease resistance has given oat breeders the tools and resources to support ongoing improvements in yield stability and physical grain quality, and drive more inclusion of oats in mixed rotations.

Disease traits

This GRDC investment has identified and selected disease resistance traits of priority in oat germplasm through the National Oat Breeding Program led by the South Australian Research and Development Institute (SARDI).

The disease traits identified as the highest priority for the three-year project were cereal cyst nematodes (CCN), Septoria, crown rust, stem rust and red leather leaf.

Each year, the National Oat Breeding Program has screened advanced breeding material and diverse germplasm, including resources from international collections such as the Quaker International Oat Nursery, for disease resistance. Partner agencies have included the Western Australian Department of Primary Industries and Regional Development (Septoria), the University of Sydney (oat crown rust and stem rust) and SARDI (CCN).

Building on these facilities and established genetic resources has enabled researchers to screen a wider range of germplasm and develop molecular screening tools to accelerate genetic gain for disease resistance in oat breeding.

Completed in 2020, the project has an impressive list of achievements including:

• genetic mapping of two loci for CCN resistance from Kangaroo oats, and development of markers to improve selection in oat breeding;
• development of oat mapping populations to assess the heritability of moderate resistance to Septoria in the line LA03022S-L3 and two new lines from the 2019 Quaker International Oat Nursery;
• development of germplasm resistant to oat crown rust and oat stem rust through backcrossing to lines 03198-18BG, Mitika, Bannister, Kowari, Williams and Wintaroo;
• preliminary identification of molecular markers to select for durable oat crown rust resistance loci; and
• establishment of a protocol for the production of red leather leaf inoculum and screening of breeding material and diverse germplasm.

Tackling Septoria

SARDI pre-breeding research for Septoria resistance in oats is continuing under a new three-year GRDC investment. Septoria is the most significant and costly disease in oats, particularly in the high-rainfall regions of WA and in dwarf varieties. Increased oat crop production and the retention of oat stubble is leading to an increased incidence of Septoria disease, which not only causes significant yield loss but also reduces grain quality through increased screenings and dark spots on groats.

This will see the development of an international set of differential oat lines for detecting virulence specificity in the Australian pathogen population, identification of disease pathotypes suitable for evaluating resistance, and genetic analysis with molecular markers to improve variety selection.

This work will complement other GRDC-invested research investigating fungicide strategies by targeting the delivery of stable genetic resistance and tolerance, which will ultimately provide a better economic outcome for growers.

More information: Dr Tim Sutton, 08 8429 0787, tim.sutton@sa.gov.au