Australian 'water-miser' sunflower hybrids that stand up to moisture stress and yield better under dry conditions are being developed in research now under way in Queensland.
CSIRO Tropical Agriculture scientists started the task by surveying the extent of dry conditions that sunflowers have to battle in key production areas. The research team computer-simulated the growth of a sunflower crop, using 105 years of weather data from Biloela, Dalby Emerald, Moree and Gunnedah. The simulations showed that the frequency of moisture stress was high in all rain-fed sunflower-growing areas.
The model also showed that hybrids with high transpiration efficiency — a measure of how efficiently they use water — had significantly better grain yield in dry conditions. The researchers are therefore selecting germplasm with high transpiration efficiency using techniques developed by ANU scientists and used by CSIRO Plant Industry colleagues in Canberra in the successful development of water-use-efficient wheat varieties (see story pl3).
The researchers hope to identify useful breeding lines to cross and select new material. "As the genetic control of the water-use efficiency trait is likely to be complex, we will be developing DNA markers to help track this trait through sunflower breeding programs," said research geneticist Chris Lambrides.
He said the project had a close alliance with many public and private sector sunflower breeding programs and had now sampled more than 250 accessions, lines and hybrids.
"Invariably, the lines with high transpiration efficiency trace back to wild species that are adapted to dry or saline conditions."
"These lines are being crossed to elite Australian sunflower lines to ensure that high transpiration efficiency is transferred to varieties in private-sector programs as soon as possible. The first experimental hybrids selected for high transpiration efficiency are being tested in summer-autumn plantings this year in the Queensland Central Highlands."
Program 2.5.1 Contact: Dr Chris Lambrides 07 3214 2213