In a new study by the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), researchers evaluated oil sorghum lines in Nebraska and Illinois over two years to quantify genotype-by-environment effects on agronomic performance and triacylglycerol accumulation. The research is published in the Plant Biotechnology Journal.
The current domestic supply of plant-based oils is not adequate to meet the projected increase in domestic biofuel demand, including sustainable aviation fuel (SAF). In this context, engineered oil sorghum (OS) is being developed as a novel bioenergy crop that accumulates triacylglycerol (TAG) in its vegetative tissues. Field testing of new engineered OS lines is a key step in developing an ideal OS hybrid for SAF production.
The researchers assessed the physiological and agronomic performance of four OS lines across a range of environmental conditions in the potential growing region for OS.
Field trials across two states
Four engineered OS lines derived from TX430 grain (TxHO-2, TxHO-3) and Ramada sweet (RmHO-1, RmHO-2) sorghum genetic backgrounds were grown alongside wild-type (WT) lines in Nebraska and Illinois over two years (2023–2024) to quantify genotype-by-environment effects on agronomic performance and TAG accumulation.
TX430 OS lines averaged 15.0 g kg⁻¹ TAG in leaves and 12.3 g kg⁻¹ in stems, representing 25- and 13-fold increases over WT, respectively. Ramada OS lines averaged 26.1 g kg⁻¹ TAG in leaves and 12.3 g kg⁻¹ in stems, 25- and 13-fold increases over WT, respectively.
Biomass shaped oil yield
TX430 lines exhibited an average 18% reduction in biomass overall relative to WT. However, the line with the highest cumulative TAG (TxHO-2) did not differ significantly from WT. Ramada OS biomass yield was similar to WT. TAG yield was greatest in TxHO-2 (190 kg ha⁻¹) and RmHO-1 (335 kg ha⁻¹), with biomass yield differences, rather than TAG concentration, driving the difference between the two lines.
Nutrient removal (N, P and K) increased in TX430 OS lines but not in Ramada lines, while structural carbohydrates and ash concentrations were unaffected.
This work confirms vegetative lipid accumulation as a viable strategy for high-biomass sorghum, supporting its potential as a SAF feedstock. Future work is needed to optimize agronomic practices.