Exploring wheat genetic resources with shoot and root high-throughput phenotyping to improve adaptation to drought

Water availability is a major environmental stress threatening crops production worldwide, which impedes crop performance at all growth stages. Among a wide range of traits linked to drought resistance the root system plays an essential role in ensuring plant productivity. Roots are of fundamental importance to soil exploration and below-ground resource acquisition, and hence are strongly related to plant adaptation to drought. In this study, high-throughput phenotyping was used to characterize the root system architecture of 40 durum wheat landraces. Root phenotyping was carried out using the GrowScreen-PaGe phenotyping platform at the Institute IBG-2: Plant Sciences (Forschungszentrum Jülich GmbH). Most traits showed large variations within genotypes. In general, root length traits contributed more than shape and branching related traits to the overall variability of the root system architecture among genotypes. On the basis of these results, 15 genotypes were further selected for above-ground traits under well-watered and drought conditions, using the Scanalyzer-3D LemnaTec. Images in different spectral ranges were used to examine the dynamic phenotypic response to drought. We extracted and quantified a list of representative phenotypic traits from the digital imaging data. Phenotypic RGB image analysis allowed to select some interesting genotypes (susceptible and resilience) considering the morphometric (biovolume, growth dynamic and compactness) and colorimetric (yellow and green index) parameters. The data obtained with high-throughput phenotyping could be used to advance our understanding of plant performance and resilience to drought, and to identify new varieties with higher adaptability to harsher drought spells under current and future climate change.