Enhancing sorghum yield and grain quality through efficient nitrogen utilization - Challenges and opportunities

Authors: OSTMEYER, TROY - KANSAS STATE UNIVERSITY; BAHUGUNA, RAJEEV - RAJENDRA INSTITUTE; KIRKHAM, MARY - KANSAS STATE UNIVERSITY; Bean, Scott; JAGADISH, S.V. - KANSAS STATE UNIVERSITY

Submitted to: Frontiers in Plant Science
Publication Type: Review Article
Publication Acceptance Date: 2/8/2022
Publication Date: 2/27/2022
Citation: Ostmeyer, T., Bahuguna, R.N., Kirkham, M.B., Bean, S.R., Jagadish, S.K. 2022. Enhancing sorghum yield and grain quality through efficient nitrogen utilization - Challenges and opportunities. Frontiers in Plant Science. 13. Article 845443. https://doi.org/10.3389/fpls.2022.845443.
DOI: https://doi.org/10.3389/fpls.2022.845443

Interpretive Summary: Sorghum is an important crop, which is widely used as food, forage, fodder and biofuel. Despite its natural adaption to resource-poor and stressful environments, increasing yield potential of sorghum under more favorable conditions holds promise. Nitrogen is the most important nutrient for cereal crops, having a dynamic impact on growth, yield and grain quality. Thus, increasing nitrogen use efficiency (NUE) in sorghum would provide opportunities to achieve higher yield and better-quality grain. This review discusses factors related to NUE and provides a better understanding of the genetics and molecular pathways involving NUE and identifies research areas such as targeted high throughput sensor-based phenotyping and monitoring as critical for identifying lines or developing management practices to enhance NUE in sorghum.

Technical Abstract: Sorghum is an important crop, which is widely used as food, forage, fodder and biofuel. Despite its natural adaption to resource-poor and stressful environments, increasing yield potential of sorghum under more favorable conditions holds promise. Nitrogen is the most important nutrient, having a dynamic impact on all growth, yield and grain quality determining processes. Thus, increasing nitrogen use efficiency (NUE) in sorghum would provide opportunities to achieve higher yield and better-quality grain. NUE is a complex trait and regulated by several genes. Hence, exploring large genetic diversity for NUE can help understand key physiological processes and develop molecular markers associated with NUE, which can be utilized to develop high NUE sorghum genotypes with greater yield potential. Research on improving NUE in sorghum suggest traits such as stay green, and altered canopy architecture (water-deficit conditions); and an optimized stay green and senescence ratio and efficient N translocation to grain (favorable conditions) as potential breeding targets to develop high NUE sorghum genotypes. Hence, sorghum breeding programs will need to reconsider strategies and develop environment specific trait(s)-based breeding programs for better adaptation and improving productivity and grain quality under wide range of environments. Unprecedented progress in sensor-based technology and artificial intelligence in high throughput phenotyping platforms has provided new horizons to explore complex traits such as NUE, in situ. A better understanding of the genetics and molecular pathways involving NUE accompanied by targeted high throughput sensor-based indices is critical for identifying lines or developing management practices to enhance NUE in sorghum.