QAAFI Science Seminar: Future Science Leaders

The Future Science Leaders is a series of seminars that will run as a part of the QAAFI Science Seminar Series through out the year. These seminars are dedicated to showcasing early-career and student researchers. Each seminar will feature two students, from two different areas of research to encourage inter-disciplinary discussion across industries. 

Topical application of dsRNA for endogenous gene control
William Nak, Centre for Horticultural Science

RNA interference (RNAi) is a genetic method used to silence target gene expression, a process that is reliant on double stranded RNA (dsRNA) identical to the mRNA of the target gene. RNAi through genetic modification is a robust method, but comes with the downside that the resulting plants are transgenic/GMO. Topical application of dsRNA has shown promise as a plant protectant against viruses, yet research into application of dsRNA for target endogenous gene knockdown is limited. This talk will focus on experiments, gene targets and preliminary results from my PhD in applying dsRNA to plants.

Identifying Sorghum Plant Types Adapted to Moisture Stress Areas of Ethiopia​
Alemu Tirfessa, Centre for Crop Science

Sorghum is an important food and feed crop in the dry lowland areas of Ethiopia, where farmers grow both early sown long-duration landraces and late sown short-duration improved varieties. Because timing and intensity of drought stress can vary in both space and time, an understanding of major physiological traits (G), environmental attributes (E), management practices (M) and their interactions (G×E×M) is a key to optimise grain and forage yield in a given the limited available resources. Crop simulation modelling can provide insights into these complex G×E×M interactions. The aim of this study was to identify plant attributes that would confer adaptation to prevalent drought patterns in Ethiopia and facilitate their incorporation in the breeding programs. This was achieved by (1) developing predictive phenology models of a range of Ethiopian germplasm, (2) parameterising and validating the APSIM-sorghum model for the development and growth of Ethiopian germplasm, and (3) quantify the productivity risk and trade-off associated with early vs late sowing in the dry lowlands of Ethiopia. Parameterisation of Ethiopian germplasm with contrasting phenology reflected experimental results that this germplasm can vary significantly in (1) the ability to progress crop development under low temperatures, (2) biomass partitioning between leaves and stems, and (3) grain number produced per unit of biomass accumulated. Combining these crop parameters with soil characterisation and weather records at Melkassa and Miesso provided good validation of growth and development of the APSIM-sorghum model for experiments conducted at these locations. Risk analyses showed trade-offs between biomass and grain yield for early and late sowing. Early sowing tended to produce greater biomass except in poor seasons, whereas late sowing tended to produce greater grain yield except in very good seasons. This study can inform identification of traits and management options to maximise crop adaptation and grain yield in Ethiopian dry lowlands

About the speakers

William Nak 

Alemu Tirfessa 

Alemu is a PhD candidate working on Sorghum Physiology under the supervision of Dr.Erik van Oosterom, Prof Graeme Hammer and Prof David Jordan. Alemu has obtained a Bachelor in Plant Science and a Masters in Plant Breeding. His research focus has been around a sorghum improvement program in Ethiopia since 2003, to develop and deliver improved sorghum technologies to farmers.