New on-farm frost test to ‘turbo drive’ research into impact on grain crops in WA

A new on-farm frost test is set to “turbo drive” research into the weather phenomena’s devastating impact on grain crops, producing results within just 40 minutes. Dubbed the INB qPCR test, it was developed by Department of Primary Industries and Regional Development staff as part of a one-year research initiative to identify and quantify INB from samples collected from WA cropping systems, associated with a three year Council of Grain Growers Organisations project. It followed their discovery of a molecular marker to identify and quantify ice nucleating bacteria, which elevate the risk of frost damage, which costs WA growers $360-700 million in crop losses a year. The INB produce a protein that mimics an ice nucleus — where ice is formed — acting as a template that attracts water molecules and builds the size of the ice crystal. The test involves using the molecular marker while undertaking a quantitative polymerase chain reaction (qPCR) test, to detect INB on and within the leaf surface. DPIRD research scientist Esther Walker said the quick turnaround time for results would shave a week off the conventional process. “Combining this marker with a portable qPCR device means we can determine bacterial numbers accurately and rapidly in the paddock, without the need to transport samples back to Perth,” she said. “This innovation will provide researchers with valuable information on the presence and distribution of INB over the growing season in a matter of hours, opening the door to get a better understanding on the interplay between the plant, INB and environment.” The findings are hoped to assist plant breeders to develop new grain cultivars that are resistant to INB and help scientists devise effective crop management strategies and applications to reduce frost risk. The research is now being advanced as part of a three year DPIRD project to examine the use of chemical and biological products that inhibit INB, with co-investment from the Grains Research and Development Corporation. DPIRD research scientist Amanuel Bekuma said preparations were underway to test up to eight products at the department’s Dale research site and in a controlled environment facility at South Perth. “The wheat and barley used in the trial will first be treated with two strains of the INB to ensure they are suitably infected to assess the bacteria’s response to the various treatments,” she said. “The treatments will then be applied at the recommended rate at different growth stages, mostly during frost susceptible stages and/or prior to a frost event, and plant responses recorded.” The initiatives build on previous DPIRD research which identified older leaves of wheat and stubble where INB infection could trigger freezing at temperatures as warm as -4.7 and -5.7C respectively, while uninfected plants could remain supercooled up to -8C. DPIRD will also continue research assessing how wheat genotypes vary in their ability to host INB, building on previous findings that suggest variation occurs with seedborne INB populations. Online tools and advice are available at agric.wa.gov.au/frost/frost-tools-and-support.