Wild relatives to the rescue again
Wild overseas barleys are being used to overcome yield losses caused by major barley diseases in Australia.
The CSIRO Plant Industry’s Tony Brown told a recent international barley symposium that researchers have identified useful wild sources of resistance to leaf scald and leaf rust in barley, and a promising one for crown rot.
Dr Brown collected the wild barleys from Iran, Turkey, Israel and Morocco some years ago.
These were crossed with the then very popular Clipper malting variety. “I was originally looking to the wild barleys to provide more general agronomic adaptation for traits such as drought tolerance,” Dr Brown said. “However, plant breeders including Barbara Read of NSW Agriculture noticed that some of these crosses in the field were resistant to barley leaf scald.”
He said this led Dr Read to develop Tantangara some years ago, the first Australian commercial barley to contain the wild barley genes. Scald is such a variable pathogen that some ‘spots’ of scald are now being noticed on Tantangara. The researchers are returning to the wild relatives for more scald resistant genes.
Crown rot and leaf rust resistance also look promising
Crown rot resistance has been the focus of the Clipper/wild barley crosses for Graham Wildermuth of the Queensland Department of Primary Industries. Back crossing is still in progress but results look encouraging and the search for a molecular marker is also under way.
“Resistance to leaf rust has been achieved and markers have been found through a collaboration with David Poulsen of Queensland DPI,” Dr Brown said.
“Greg Platz, also of Queensland DPI, is working with the wild barley crosses hoping to find resistance to the net form of net blotch. I have seen some hopeful reactions in this program.”
Dr Brown said researchers have so far found no useful resistance genes to Rhizoctonia or barley yellow dwarf virus in the wild barley/Clipper crosses.
Contact: Dr Tony Brown 02 6246 5081