SummarySignificant variation in photosynthesis and growth in 64 wheat cultivars was explained by differences in photosynthetic capacity, operation and CO2 diffusion. Natural variation in photosynthesis is an underutilized resource for potential crop improvement.

To meet the growing demand for food, substantial improvements in yields are needed. This is particularly the case for wheat, where global yield has stagnated in recent years. Increasing photosynthesis has been identified as a primary target to achieve yield improvements. To increase leaf photosynthesis in wheat, the level of the Calvin–Benson cycle enzyme sedoheptulose-1,7-biphosphatase (SBPase) has been increased through transformation and expression of a Brachypodium distachyon SBPase gene construct. Transgenic lines with increased SBPase protein levels and activity were grown under greenhouse conditions and showed enhanced leaf photosynthesis and increased total biomass and dry seed yield. This showed the potential of improving yield potential by increasing leaf photosynthesis in a crop species such as wheat. The results are discussed with regard to future strategies for further improvement of photosynthesis in wheat.This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

Flag leaf longevity and operating photosynthetic rates at ambient CO2 and a range of light levels correlated with grain yield of UK field-grown wheat, revealing new targets to enhance crop productivity.