Is canopy temperature suitable for high throughput field phenotyping of drought resistance of winter rye in temperate climate

Abstract The present study investigated genotypic differences in canopy temperature of 218 testcross progenies of a recombinant inbred lines mapping population of winter rye. For this purpose, we repeatedly measured canopy temperature (Tc) and air temperature (Ta) differences (Tc − Ta) in field trials on two locations with sandy soils in northern Germany, two water treatments (rainfed and irrigated) in two experimental years. The experimental conditions therefore covered a wide range of drought stress conditions between stem elongation and ripening under a high variation of environmental boundary conditions. Genotype effects on (Tc − Ta) were significant in both water treatments and were correlated to grain yield reduction under drought stress. With the chosen statistical model, we were able to account for moderate time-series effects and short-term fluctuations caused by changing boundary condition during single screens of (Tc − Ta). We could show that under certain weather conditions (Tc − Ta) can detect differences in drought stress tolerance more accurate than grain yield determination of rye.