Non-Destructive High-Throughput Image-Based Phenotyping for Drought Tolerance in Barley

Plants are phenotyped on a daily basis over the whole experimental phase using a fully automated system consisting of conveyer belts, a weighing & watering station and three imaging systems. Top and side cameras are used to capture images of individual plants at different wavelengths - visible light, fluorescence and near infrared. To set-up a drought stress protocol, a core set of 16 diverse spring barley cultivars has been analyzed in several replications for drought tolerance in the vegetative stage. Stress is applied four weeks after sowing by withholding water. Control plants remain well-watered. After a stress period of 18 days plants are re-watered and kept well-watered again for another two weeks. At the end of this recovery period, fresh and dry weights of green biomass are compared with estimated digital biomass. Correlations of fresh weight and digital biomass were high (0.95). After stress treatment biomass was reduced by 55 % and plant height by 16 %. Cultivars showed phenotypic differences both under well watered and under drought conditions.

Next, a population comprising more than 200 spring barley genotypes will be analyzed using the automated imaging system. This collection is already genotyped using 7864 SNP markers. We will then combine all data in an GWA to detect drought tolerance related QTL.