Ideotype‐Based Approach for Improving Root Traits in Crop Plants for Climate Resilience: How Far Have We Zeroed In on the Best Fit?

Abstract The unprecedented challenges to crop production driven by climate change drivers warrant the development of resilient crop varieties to sustain crop yield. In the present and future, climate, drought, salinity and temperature stress will be the major yield‐limiting factors. Roots are the primary responders to drought, flooding and salinity and assume a key position in developing plant resilience. Root architecture has emerged as a promising focal point in breeding efforts aimed at developing resource‐efficient crops. However, crop selection frequently prioritises shoot performance exclusively because evaluating root traits is a more intricate process. Improving root traits will be a pivotal factor in increasing the efficiency of water and nutrient capture, reducing yield gaps and providing the necessary foundation for the ‘Evergreen Revolution’, which is essential for aligning crop production with the needs of the growing human population. However, building an ideotype for root system architecture (RSA) has been precluded by obvious difficulties in reliable phenotyping and greater growth plasticity and abiotic stress response of root, as in some cases, the plasticity can be maladaptive due to greater metabolic costs. Nevertheless, a large body of experimental data has been generated to build an optimum root ideotype for diverse stressful environments. In this article, we provide an overview of the typical RSA ideotypes under various stresses that have been suggested in previous research and indicate functional evidence on the role of root phenes that could help breeders in their efforts to include root traits in their selection pipelines for abiotic stress tolerance, aimed to improve the resilience of crops. Such an approach can deliver quicker improvements compared to selection solely based on yield, particularly in stressful environments, using a more precisely tailored approach to increase long‐term sustainability and mitigate the impacts of stresses. Also, the probabilities for aligning future abiotic stress breeding strategies based on RSA and other traits are discussed. Prioritising these ideotype‐related traits in breeding programs could significantly boost crop production and enhance the long‐term sustainability of agriculture.