Mr Brendan Kupke1,2, Dr Haoyu Lou2, Dr Chris Brien2, Ms Melissa McCallum1, Associate Professor Bettina Berger2, Dr Nathaniel Jewell2, Dr Rhiannon Schilling1,2,3
1South Australian Research and Development Institute, Urrbrae, Australia, 2The University of Adelaide, Urrbrae, Australia, 3Flinders University, Bedford Park, Australia
Biography:
Brendan works as a cereal research agronomist for SARDI and is an affiliate associate lecturer at The University of Adelaide based at the Waite Institute in Adelaide. Specialising in wheat and barley, he has worked across a range of projects including phenology, time of sowing, frost, plant hormones, remote sensing and drones, across the low to medium rainfall zones of South Australia.
Abstract:
Environmental stresses (i.e. frost, heat and water stress) cause significant grain yield losses by reducing both grain size and number. Manual measurement of individual grains in a spike has been time-consuming, limiting the capacity and ability for accurate assessment. Moreover, parameters like seed volume and density, crucial for grain quality, are challenging to measure manually and can be influenced by abiotic factors resulting in grain pinching. A novel high throughput X-ray CT phenotyping facility at The Plant Accelerator now provides an opportunity to comprehensively analyse cereal spike and grain characteristics. Wheat spikes collected from a field trial with six varieties and four times of sowing were analysed using an X-ray CT to determine the effect of abiotic stress on grain size and number. The accuracy of the X-ray CT results was validated against traditional manual sterility assessments. Numerous frost events (<0°C) occurred at the field trial during early flowering, significantly influencing grain sterility in the early times of sowing for Vixen (85%) and Scepter (25%). Comparing early sowing time to late ones, X-ray CT results identified significant reductions in grain count, weight and volume, especially in Vixen. The X-ray CT facility provides a new method for analysing grain characteristics in a rapid, high-throughput, and quantitative manner reducing human bias in comparison to current manual measurements. This unbiased analysis of quantitative features of cereal spikes could lead to new insights and improved management systems for abiotic stresses in broadacre agronomic research.