Concepts and Strategies in Plant Sciences | 2021
Phenotyping Root System Architecture, Anatomy, and Physiology to Understand Soil Foraging
Abstract
Increasing plant resilience in the face of climate change is a major challenge for the next century. At the same time, combatting environmental pollution from fertilizer use in agriculture is necessary. Optimized root systems would allow crops to withstand drought and to more efficiently use fertilizer, which in turn would drive plant growth and yield performance. Because roots are difficult to access in the soil, they are difficult to measure, or phenotype. This “phenotyping gap” is a major impediment to research seeking to understand how roots forage and influence crop performance. At the same time, even known important root traits, or phenes, are difficult to incorporate into crop breeding programs that rely on selection pressure towards beneficial phene states. However, progress in root phenotyping has been made with accessible tools available now for root system architecture. Root anatomy and physiology are the new frontiers for high-throughput phenotyping of crop roots. This chapter highlights the most practical methods to use for field root phenotyping, with a focus on how these methods could be combined to phenotype multiple root phenes sequentially. Dense root phene datasets would allow statistical insights to be made for understanding how root phene integration is important for crop performance. These methods are ready to use today, so the way forward to address the “phenotyping gap” to understand and breed for root phenes is clear. We have to get in the field, get our hands dirty, dig harder, and dig deeper.