Andrew Fletcher, Jack Christopher, Karine Chenu
The University of Queensland, Queensland Alliance for Agriculture and Food Innovation (QAAFI), 203 Tor Street, Toowoomba, Queensland 4350, Australia. Email: firstname.lastname@example.org
Wheat productivity is frequently limited by soil-water deficit in rain-fed environments. Increasing the amount of plant biomass produced per unit of water transpired (transpiration efficiency, TE) can lead to gains in crop yields, particularly when water availability is limit. Currently, the ability to select for TE is limited by typically low-throughput and labour-intensive screening techniques. To investigate the effects of crop stage and environment on TE, 11 wheat varieties were sown at three dates, and grown for different durations in continuously watered pots in a glasshouse experiment. TE was calculated as the ratio of plant biomass over cumulated water use for plants grown to different stages. Significant genotypic variations in TE were observed when measurements were taken over a sufficient duration, i.e. for later growth stage. Genotype ranking for TE slightly varied across treatments, but overall it tended to retain a general consistency irrespectively of the sowing and harvest dates. This result indicates that multiple short trials can be carried out within a season to allow increased throughput of genotypes for TE screening. Increasing throughput to effectively screen for TE at the plant level is essential to make the process of selecting for TE viable at a commercial crop breeding level.