Wheat study to help limit fungal disease

The path has been cleared by WA researchers to develop new and improved wheat varieties with triple resistance to some of the most significant fungal diseases.

Yellow spot, nodorum blotch, and powdery mildew cost the State’s wheat industry more than $200 million each season in lost production and control costs.

Spin-off research by the Department of Primary Industries and Regional Development, from a long-running yellow spot project co-funded by the Grains Research and Development Corporation, has identified the source of genes with the triple resistance.

Disease screening of 2445 wheat lines from around the world found seven lines with moderate to high levels of resistance to the three fungal diseases.

Five of the seven lines came from Mexico and Turkey, via the International Maize and Wheat Improvement Centre, while two lines originated in Syria, from the International Centre for Agricultural Research in Dry Areas.

DPIRD senior research scientist Manisha Shankar said it was rare to discover good levels of resistance to all three diseases in the same line.

“Two of the seven lines have high levels of resistance for all three diseases, while three lines have high levels of resistance for two diseases and moderate levels of resistance for one disease,” she said.

“The remaining two lines have high levels of resistance for one disease and moderate levels of resistance for two diseases.

“As a comparison with the 40-odd current commercial wheat varieties, only DS Bennet and Magenta have high levels of resistance for one disease and moderate levels of resistance for two diseases.”

DPIRD has begun integrating these lines into its doubled haploid program to develop new wheats by crossing with seven existing parent varieties: Magenta, King Rock, Hydra, Ninja, LRPB Havoc, Kinsei and Rockstar.

As part of the on-going yellow spot resistance research, new yellow spot-resistant genes were identified from analysis of 17 doubled haploid populations and an association mapping panel.

The project team used these resistance genes to develop 51 new wheat lines with yellow spot resistance, which have a combination of three, four and six genes “stacked” into fixed lines that are adapted to western and southern production regions of Australia.