RESEARCHERS have developed wheat lines that are resistant to crown rot, writes PETER HEMPHILL
Queensland scientists believe they have made a breakthrough in breeding against crown rot in wheat.
In what is considered to have been the Holy Grail for Australian plant breeders, a research team from the Department of Economic Development, Employment and Innovation has bred a number of wheat lines showing resistance to the complex fungal disease.
But the first commercial disease-resistant wheat variety is not expected to be released for about another seven to 10 years.
It is estimated crown rot costs the Australian wheat industry about $79 million a year in yield losses.
The Grains Research and Development Corporation has invested heavily over the years in solving the crown rot problem.
DEEDI scientist Damian Herde said the research team had finally developed a variety of genetically resistant wheat that would help breeders to produce disease-free, superior varieties for the future.
About 30 lines of wheat showing crown rot resistance have been sent to breeding groups across Australia.
"This outcome represents years spent identifying breeding material with a desirable gene, plus several more years purifying and crossing it many times to lines with many other sets of genes," Dr Herde said.
"These parent lines with the new gene are now being crossed by commercial plant breeders.
"It will be another seven to 10 years of this crossing and selecting process before we finally see the release of a commercial crown rot resistant wheat variety, but we believe this is now a certainty."
Dr Herde and his researchers have used genetic research to gain a greater understanding of why some wheat plants were resistant to crown rot and others were not.
"While the idea of genetic resistance to crown rot has been known in the scientific community for decades, the ability to capture this resistance and produce a successful disease-free variety has remained elusive," he said.
"Our research has involved using old-fashioned techniques combined with modern understanding to identify how genes are passed on by the parent plants resulting in disease-resistant plants.
"This has helped us to properly screen, cross-breed and continue to develop new wheat lines, which we believe will have even greater disease resistance."
Crown rot is more of a problem in northern NSW and Queensland than in southern Australia. But Victorian Department of Primary Industries plant pathologist Grant Hollaway said it was a problem in southern regions, depending on whether a dry spring eventuated.
Dr Hollaway said crown rot caused losses of 2-3 per cent a year, but individual crops could suffer as much as 10 per cent in lost grain yield in dry seasons.
He said plant pathologists in Victoria were watching to see if the disease developed this season.
Victoria has so far had a dry spring, although there was plenty of subsoil moisture to keep crops developing.
