Opportunities to improve genetic wheat yield potential

Wheat yield potential could be increased by 50% or more –theoretically– through the genetic improvement of radiati on use efficiency (RUE). However, to achieve agronomic impacts, structural and reproductive aspects of the crop must also be improved. Attempts to increase RUE will focus on increasing the efficiency of Rubisco, introduction of C4-like traits such as CO2 concentrating mechanisms, and improvement of light interception and photosynthesis at the spike and whole canopy levels. For extra photo-assimilates to translate into increased grain yield, reproductive aspects of growth must be fitted to a range of agro-ecosystems to ensure that stable expression of a high harvest index (HI) is achieved. Adequate partitioning among plant organs will be necessary to achieve favorable expression of HI, and to ensure that plants with heavier grain have strong enough stems and roots to avoid lodging. Trait-based crossing strategies will aim to achieve their simultaneous expression in elite agronomic backgrounds and wide crossing will be employed to augment genetic diversity where needed. Genomic selection approaches will be employed, especially for difficult-to-phenotype traits. Products will be delivered to national wheat programs worldwide via CIMMYT’s international nursery systems and are expected to make a significant contribution to global food security.