Dynamics of Root Systems in Crop and Pasture Genotypes over the Last 100 Years: Lessons Learned

Plant root system architecture (RSA) performs several key adaptive functions, including nutrient and water uptake, biotic interactions in the rhizosphere, and soil anchorage. It is crucial for crop productivity and plant fitness and can be targeted to improve crop performance under diverse edaphic and climatic conditions. This chapter highlights advances in the root morphology research in crop and pasture plants over the last 100 years. The chapter covers (i) the role of key morphological features (rooting depth, root hairs, and root branching) in resource acquisition, and RSA plasticity and dynamics; (ii) the genes/phytohormones and transcription factors controlling the genetics of RSA; (iii) the role of roots in improving crop production on low fertility and marginal soils; and (iv) root ideotypes for resource acquisition (water and nutrients) under sub-optimal conditions.