Congratulations to Pieter Hendriks, winner of the APPF’s 2021 Postgraduate Internship Award (PIA). Pieter will work with the APPF’s ANU Node to look at the impact of above-ground vigour in wheat on the root architecture.

The Award will allow Pieter to run experiments to look at the early development of wheat cultivars in growth conditions mimicking field growth conditions on both the light quantity and quality as well as temperature and humidity. His study will investigate the root systems of winter wheat plants that vary in above-ground vigour, and the impact of increased above-ground vigour on root traits that influence the competitive ability of the wheat. 

His PhD thesis: The role of root architecture and associated rhizosphere interactions in breeding for weed competitive wheat cultivars, concentrates on below ground competitiveness. Until now, Pieter says few studies have attempted to understand the mechanisms that link above and below-ground vigour, or how below-ground vigour traits underpin the processes associated with weed competitiveness. “I hope to identify below-ground traits and link these to key above-ground traits, known to impact the competitive ability of winter wheat. I observe the below-ground competitiveness both in the field and in controlled environments. I study the root system architecture but also root exudates and rhizosphere interactions modulated by wheat roots and the soil microbiome.” This  PhD project follows in the footsteps of studies by wheat breeders and weed scientists in recent years at Charles Sturt University and CSIRO to develop wheat genotypes highly competitive against agronomically important weeds.

The study made possible with this Award will contribute to his PhD project, “the possibility provided by the growth capsules at the APPF ANU node will allow me to build a bridge between my controlled environment results and the data collected in the field this year,” Pieter said. Using APPF’s controlled growth environment, he will be able to collect and analyse entire root systems produced in soil conditions resembling that encountered in the field site. “There was a missing link in my study. It was impossible to sample early plants this year due to the climate and the Covid restrictions. Thanks to these facilities I will be able to grow plants in near field conditions while having the luxury of controlled environment measurements, this is more than I hoped for to fill the gap in my research”, Pieter added.

His study will investigate the root systems of spring wheat plants that vary in above-ground vigour and the impact of increased above-ground vigour on root traits that influence the wheat’s competitive ability. “I will use field soil on top of the field climate conditions, but at the same time, I will be able to individually size my seeds for my experiments and recover full root systems. These are near impossible tasks in the field”, Pieter added.

Pieter will assess leaf size (width and length) and leaf area, capturing plant images at harvest and studying entire root systems using root scans and a root image analysis program. Data collected will include root length, diameter, branching patterns and root and shoot dry weight for each genotype evaluated.

The Postgraduate Internship Award supports the successful applicant’s costs for the use of phenotyping facilities, and travel and accommodation if needed. You will find Pieter on our contact us page. Pieter acknowledges the support of the APPF, Charles Sturt University, the Graham Centre, CSIRO, GRDC and the Tim Healey Memorial Scholarship for making his work possible.