GRDC Western Panel deputy chairman Professor Richard Oliver said growers could also use a range of decision support information around disease resistance and agronomic performance to add rigour to their on-farm observations.

Prof Oliver, who also heads up the Australian Centre for Necrotrophic Fungal Pathogens at Murdoch University, has discovered a protein associated with leaf diseases commonly known as Stagonospora (or Septoria) nodorum blotch and Tan (or Yellow Leaf) Spot.

The protein, known as ToxA, is produced by both the fungi that cause these diseases – Stagonospora nodorum and Pyrenophora tritici-repentis – and interacts with wheat lines with the Tsn1 Gene, making them more susceptible to the two diseases.

Using the ToxA protein as a sensitivity marker, Professor Oliver’s team has identified wheat varieties which are sensitive to ToxA and therefore more susceptible to Stagonospora nodorum blotch and Tan Spot.

“It’s another method of more accurately zeroing in on the causes of susceptibility,” Professor Oliver said.

“The identification of the gene that is associated with susceptibility gives breeders an easy way to eliminate susceptible wheat lines early in the breeding process.”

“This can be used in conjunction with existing Department of Agriculture and Food Western Australia disease ratings to make decisions about the suitability of varieties from a disease perspective.

“Growers with crops affected by Stagonospora nodorum blotch and Tan Spot can now choose from a list of cultivars that are insensitive to ToxA and therefore have less severe disease symptoms.

“More such cultivars are expected as wheat breeders begin to consciously select for lines which have lost the Tsn1 gene,” Professor Oliver said.

Details of the research results, including the list of ToxA insensitive cultivars, can be found here.