February 3, 2013
Genome sequencing of the wheat disease tan (yellow) spot pathogen is expected to help researchers boost the productivity of the Australian wheat industry by tens of millions of dollars in coming years. The genome sequence for Pyrenophora tritici-repentis (PTR) was published recently by United States and Australian researchers, following collaborative research between the countries. According to the Australian Centre for Necrotrophic Pathogens (ACNFP), which is supported by the Grains Research and Development Corporation (GRDC), it will accelerate the release of more resistant Australian cultivars and improve resistance ratings for existing varieties. ACNFP director Richard Oliver said tan spot was the most costly disease affecting Australian and Western Australian cropping, and was estimated to cause national annual losses of more than $200 million. “Research carried out by Kalyx and the ACNFP in 2009 and 2010 suggested that wherever the disease is present, it causes yield losses of 0.3 to 0.6 tonnes per hectare, so $200 million may well be an underestimate,” Professor Oliver said. He said having access to the full genome sequence for PTR, the cause of tan spot, revolutionised Australian researchers’ knowledge of the fungal disease by giving them access to previously unknown tan spot virulence factors. “In recent years we’ve had access to some sequence data, which has already allowed us to help Australian plant breeders to breed improved varieties, but the pathogen has multiple weapons and the genome sequence is the key to Australian researchers finding and countering their effects,” Professor Oliver said. “Data relating to the tan spot gene ToxA – generated independently by an ACNFP-led consortium in 2006 – has also already pinpointed the cause of much of the yield losses caused by tan spot. “The area planted to ToxA insensitive varieties in WA has increased by about 25 per cent since the discovery of the gene.