PLANT BREEDERS are claiming major advances in tbeir quest to provide barley growers with varieties tolerant to three yield inhibitors - frost, drought and boron toxicity.
The acting leader of the SA Barley Improvement Program, Jason Eglinton, says the prospect of having varieties tolerant to these stresses is no longer just wishful thinking. "Yes, they have been in the too-hard basket, but now we are actually making real progress on all three fronts," he said.
"We have identified two Japanese malting varieties and the high-rainfall malting variety Franklin as having frost tolerance.
"They are being used as parents in a crossing program and, as well, we are going through lines bred over the years using these varieties to see if any have picked up the genes for frost tolerance. If any are found, it could shorten the release timeframe considerably.
"Molecular markers for frost tolerance have been developed to assist with the identification and selection of lines and there will be validation field trials at Loxton and Nuriootpa this year."
On drought tolerance, Mr Eglinton said the recent feed barley release, Keel, had performed very well in dry
2002 conditions - Keel's genetic background includes genes from a North African variety with known drought tolerance.
He said the aim was now to produce varieties even better performing than Keel in tough conditions and, to do this, drought-tolerant barley lines from Syria had been compared with local varieties.
"We have been surprised and delighted with the performance of the Syrian lines," Mr Eglinton said.
"This year we will have low-rainfall sites from Queensland to WA where the introduced lines will be benchmarked against our best current lines and, within SA, we will examine the performance of the first crosses between Keel, Barque and the overseas material."
Referring to boron tolerance, Mr Eglin ton said boron tolerance from the North African variety Sahara had been introduced to Sloop lines some years ago. However, under field conditions these lines did not produce the yield benefits expected.
Now SA Grain Industry Trust-supported work by Glenn McDonald of the University of Adelaide and Mr Eglinton has shown that instead of just getting boron tolerance from Sahara in the crossing program, other genes, including those that inhibit yield, have been carried over into the Sloop lines.
"We have had to refine the crossing strategy so that we do get the genes for boron tolerance but not the genesthat inhibit yield," Mr Eglinton said.
"Advanced boron-tolerant lines will be evaluated at up to 28 sites this year."
Frost and drought projects under the Barley Improvement Program are supported by growers and the Federal Government through the GRDC.
Program 1 Contact: Mr Jason Eglinton 08 8303 6553
National, North, South, West