Are high throughput root phenotyping platforms suitable to inform root system architecture models with genotype specific parameters ? An evaluation based on the root model ArchiSimple and a small panel of wheat cultivars.

In line with the growing demand for characterizing root system architecture (RSA) for genetic analyses and the difficulty to access plant roots in situ, high throughput root phenotyping (HTRP) platforms under controlled conditions are developed. However, an evaluation of their capacity to provide the same estimates of strictly identical root traits across platforms has never been achieved. We performed such an evaluation based on six major parameters of a RSA model, ArchiSimple using a diversity panel of 14 bread wheat cultivars in two HTRP platforms that use different growth media and non-destructive imaging systems and a conventional setup that use solid medium and destructive sampling. Significant effect of the experimental setup was found for all parameters while no significant correlation across the diversity panel between the three setups could be detected. Differences in temperature, irradiance or media in which plants are growing may partly explain both the differences in parameter values across the experiments as well as the genotype x setup interactions. Moreover, the value and the ranking across genotypes of only a subset of parameters were conserved between contrasted growth stages. As the parameters chosen for our analysis are root traits having strong impact on RSA and are close to parameters of a majority of RSA models, our results highlight the need to carefully consider both developmental and environmental drivers in root phenomics studies.