Résumé
With the genomics revolution in full swing, relevant phenotyping is now a main bottleneck. New imaging technologies provide opportunities for easier, faster and more informative phenotyping of many plant parameters. However, it is critical that the development of automated phenotyping be driven by a clear framing of target phenotypes rather than by a technological push, especially for complex constraints. Previous studies on drought adaptation shows the importance of water availability during the grain filling period, which depends on traits controlling the plant water budget at earlier stages. We will then discuss “cause” and “consequence” in phenotypes. Drawing on this, a phenotyping platform (LeasyScan) was developed to target canopy development and conductance traits. Based on a novel 3D scanning technique to capture leaf area development continuously and a scanner-to-plant concept to increase imaging throughput, LeasyScan is also equipped with 1488 analytical scales to measure transpiration seamlessly. Examples of the first applications are presented: (i) to compare the leaf area development pattern of pearl millet breeding material targeted to different agro-ecological zones, (ii) for the mapping of QTLs for vigour traits in chickpea, shown to co-map with an earlier reported “drought tolerance” QTL; (iii) for the mapping of leaf area development in pearl millet; (iv) for assessing the transpiration response to high vapour pressure deficit in different crops. This new platform has the potential to phenotype traits controlling plant water use at a high rate and precision, opening the opportunity to harness their genetics towards breeding improved varieties.