RESEARCHER Brenton Leske has been keenly monitoring the affect 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 DPIRD’s grains research scholarships, intended to boost the productivity and competitiveness of the WA 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 which are less susceptible to frost.
The research builds on his involvement in research projects undertaken by DPIRD and supported by the Grains Research and Development Corporation (GRDC), which examined the affect 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,” Mr Leske 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 DPIRD trial Mr Leske was involved in.
The trial had eight sowing dates from April 15 to June 22, 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 relationship 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,” Mr Leske said.
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,” Mr Leske said.
“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 WA in collaboration with the department.
DPIRD 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 WA 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.”
A grains research scholarship 2016 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 scholarships are supported by Royalties for Regions, as part of the DPIRD’s Boosting Grains Research and Development project.
Applications for the next round of scholarships close on Tuesday, October 31.
For more information or to apply for a scholarship visit agric.wa.gov.au and search for grains R&D postgraduate scholarships and development program or contact Alex Douglas on alex.douglas@agric.wa.gov.au or 9821 3246.
