Phenotyping for waterlogging tolerance in crops: current trends and future prospects

Review of waterlogging as a yield limiting stress and the benefits and challenges of applying a modern phenotyping approach to improving waterlogging tolerance of major crops. Yield losses to waterlogging are expected to become an increasingly costly and frequent issue in some regions of the world. Despite the extensive work that has been carried out examining the molecular and physiological responses to waterlogging, phenotyping for waterlogging tolerance has proven difficult. This difficulty is largely due to the high variability of waterlogging conditions such as duration, temperature, soil type, and growth stage of the crop. In this review, we highlight use of phenotyping to assess and improve waterlogging tolerance in temperate crop species. We start by outlining the experimental methods that have been utilized to impose waterlogging stress, ranging from highly controlled conditions of hydroponic systems to large-scale screenings in the field. We also describe the phenotyping traits used to assess tolerance ranging from survival rates and visual scoring to precise photosynthetic measurements. Finally, we present an overview of the challenges faced in attempting to improve waterlogging tolerance, the trade-offs associated with phenotyping in controlled conditions, limitations of classic phenotyping methods, and future trends using plant-imaging methods. If effectively utilized to increase crop resilience to changing climates, crop phenotyping has a major role to play in global food security.

Automated summary

This review discusses the application of a modern phenotyping approach in improving waterlogging tolerance of temperate crop species. Waterlogging is a yield limiting stress that is expected to become a more frequent and costly issue in some regions of the world. The review highlights the difficulties of phenotyping for waterlogging tolerance due to the variability of waterlogging conditions and outlines the methods and traits used in assessing tolerance. The review also discusses the challenges and future trends in improving waterlogging tolerance.