Root System Architecture in Wheat: Implications for the Breeding Program

Abstract

The current climate change is expected to affect crop geography and particularly alter the Brazilian agricultural landscape. In this scenario, in addition to crop management alternatives, it is imperative to introduce morphological traits for adaptation to these abiotic stresses into genetic breeding programs. Wheat root system architecture (RSA) describes the spatial organization of roots and is a fundamental factor in plant development. Improving this architecture can lead to plants that are more efficient in taking up water and nutrients, resulting in greater productivity and tolerance to adverse environmental conditions, such as drought and nutrient deficiencies. One of the breeding challenges is performing adequate, rapid, and affordable phenotyping and selecting the desired root trait, given the difficulty of evaluating roots underground. This work addresses theoretical aspects of the genetic components, environmental factors, and phenotyping methodologies associated with RSA, which are considered important and could play a relevant role in the selection of wheat genotypes adapted to Brazilian conditions. It is a contribution to researchers and students committed to promoting wheat production. We discuss a small subset of recent discoveries impacting RSA, believing that manipulating RSA will help develop better-performing crops. Different types of RSA offer growth advantages under different environmental conditions. In wheat, the seminal root angle is representative of the root architecture of the adult plant, thus providing a useful tool for phenotyping at early stages of plant development. RSA with a narrower, vertically oriented seminal root angle is typically more drought-tolerant. Therefore, RSA is a promising field that can be incorporated into existing breeding programs and has great potential to influence future wheat production.