Researcher Brenton Leske has been keenly monitoring the impact of cold temperatures on wheat plants at the Department of Primary Industries and Regional Development’s (DPIRD) frost nursery at Dale, west of Beverley.
Mr Leske is one of the inaugural recipients of the department’s Grains Research Scholarships, intended to boost the productivity and competitiveness of the Western Australian grains industry.
His thesis seeks to better understand how different wheat varieties respond to frost to help the development of more robust, higher yielding varieties, less susceptible to frost in the future.
The research builds on his involvement in research projects undertaken by the department and supported by the Grains Research and Development Corporation (GRDC), which examined the impact of frost on the yield components of different varieties.
Mr Leske said while previous studies had established relationships between frost and yield responses, from which varietal frost rankings have been developed, relatively little was known about which physiological responses to frost influence grain yield.
“The underlying reasons for why one variety is more sensitive to grain loss under frost than another is not well understood,” he said.
“I aim to identify mechanisms that contribute to wheat plants being more susceptible or tolerant to frost damage.”
Fifteen wheat varieties have been sown at the frost prone Dale nursery, selected out of a group of 70 from a previous department trial Mr Leske was involved in.
The trial had eight sowing dates from 15 April to 22 June, to ensure the varieties, with a range of maturities, flower across the window from July to September when frost events are likely.
An additional population of 173 lines developed from a cross between Calingiri and Wyalkatchem is also being evaluated, due to the differences in frost sensitivity of the parents.
This population will help validate past research which identified genetic regions affecting frost susceptibility, particularly loss of grain numbers.
Plants are being monitored to examine the correlation between frost and a range of yield traits, including biomass, grain size, grain number and plot yield.
Mr Leske said a particular focus of his research would be on the interrelationship between plant sugar levels and frost susceptibility.
“I’m interested in how frost damage affects the wheat’s photosynthetic capacity to convert light and water into sugar, biomass and finally yield,” he said.
“There has been an assumption amongst growers that higher sugar concentrations lower the freezing point of sap. Preliminary results from a colleague’s trial last year showed this to have a negligible effect.
“Part of the project is to assess the sugar content in different varieties and to examine the correlation between tissue sugar contents and frost induced sterility.”
Another key area of the project is an evaluation of the presence or absence of selected hormones, particularly the hormone abscisic acid (ABA), which relates to plant stress.
“ABA regulates the closure of leaf pores, or stomates, used for transpiration, which could have implications for how wheat responds to frost. I expect ABA regulation to be different amongst varieties and there might be implications for frost damage and recovery processes.”
Mr Leske’s four year PhD, supported by DPIRD and the GRDC, is being undertaken at the University of Western Australia in collaboration with the department.
Department grains research and development executive director Jason Moynihan said the Grains Research Scholarships were an investment in the long term scientific research capacity of the State.
“Brenton’s work will make a strong contribution to future wheat pre-breeding and breeding programs, which will contribute to the development of improved, more profitable varieties for Western Australian growers,” Mr Moynihan said.
“It is essential to encourage and support the next generation of scientists, to ensure WA remains at the forefront of international grains research and production.”
2016 Grains Research Scholarship recipient Xin (Bob) Du is examining the opportunity to use a non-chemical dust to protect stored grain from insects, while Leon Hodgson is working on reducing yield losses in barley caused by fungicide resistance to the disease, net blotch.
The Grains Research Scholarships are supported by Royalties for Regions, as part of the department’s Boosting Grains Research and Development project. Applications for the next round of scholarships close on Tuesday, 31 October 2017.
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