Biotechnology: aiming for consistent goals by Alec Nicol
NEW MALTING barley varieties that should take much of the hit-and-miss out of meeting malting specifications are about six years down the track, according to Victorian breeders.
A team at the Victorian Institute for Dryland Agriculture has identified chromosomal regions associated with low protein grain and has lines producing protein levels between I and 3 per cent lower than Schooner across nine test sites.
David Moody, who heads the barley improvement program, says that the new varieties will free up rotations and should mean bigger average yields.
"Where growers have been plagued by the consistent production of grain exceeding protein specifications for malting, these varieties will reduce the need to manipulate protein levels by sowing into a low fertility paddock. They also promise to open up our drier country to malting barley production."
Mr Moody said protein heritability is low compared to other quality characteristics, which makes it difficult to breed for low protein. "We know that varieties with greater numbers of kernels per head often have low protein and that other varieties differ in the amount of nitrogen they move from the leaves into the grain during filling and that also has an impact on protein levels.
"Breeding for high numbers of kernels rather than plumper kernels runs the risk of high screenings, and so we want to incorporate the genes that influence the movement of nitrogen from the leaves during filling."
Arapiles and the American variety Karl have the genes associated with low protein and grain size. "The problem with the Arapiles material is that it's very variable in the way it is expressed, showing up with a reduction in protein in someenvironments and not in others. The genes from Karl seem to be more reliably expressed and one of these genes is associated with the movement of nitrogen from the leaves to the grain. We've also identified other sources oflow protein genes in European varieties.
"We've identified the molecular markers associated with these genes and are incorporating them into our advanced breeding lines. With our new marker technologies, transferring the appropriate genes is no longer the problem but the quality requirements of the malting barley industry change.
"The difficult trick is to predict the agronomic and quality characteristics that the industry will demand in about six to eight years, the time we think it will take to produce the new varieties.
"Producing good malting barley is about getting the protein level right, neither too high nor too low. We don't want to release low protein varieties into areas already prone to producing low protein grain without having the management practices in place to ensure that average protein levels are increased."
Program 1 Contact: Mr David Moody 03 5362 2111