Can exploiting natural genetic variation in leaf photosynthesis contribute to increasing rice productivity? A simulation analysis

Abstract

Rice productivity can be limited by available photosynthetic assimilates from leaves. However, the lack of significant correlation between crop yield and leaf photosynthetic rate (A) is noted frequently. Engineering for improved leaf photosynthesis has been argued to yield little increase in crop productivity because of complicated constraints and feedback mechanisms when moving up from leaf to crop level. Here we examined the extent to which natural genetic variation in A can contribute to increasing rice productivity. Using the mechanistic model GECROS, we analysed the impact of genetic variation in A on crop biomass production, based on the quantitative trait loci for various photosynthetic components within a rice introgression line population. We showed that genetic variation in A of 25% can be scaled up equally to crop level, resulting in an increase in biomass of 22-29% across different locations and years. This was probably because the genetic variation in A resulted not only from Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase)-limited photosynthesis but also from electron transport-limited photosynthesis; as a result, photosynthetic rates could be improved for both light-saturated and light-limited leaves in the canopy. Rice productivity could be significantly improved by mining the natural variation in existing germ-plasm, especially the variation in parameters determining light-limited photosynthesis.

Nitrogen Uptake and Response to Radiation Distribution in the Canopy of High‐Yield Maize

“…Shaded leaves in the maize canopy account for >70% of the total leaf area, absorb ?30% of the total solar energy absorbed by the canopy, and contribute ?47% of total canopy photosynthesis (Song et al, 2013). Canopy photosynthesis is an important determinant for crop production (Gu et al, 2014;Kromdijk and Long, 2016). Canopy photosynthesis is an important determinant for crop production (Gu et al, 2014;Kromdijk and Long, 2016).…”

Photosynthetic Properties and Potentials for Improvement of Photosynthesis in Pale Green Leaf Rice under High Light Conditions

“…Accordingly, photosynthesis, which has shown few improvements in crop breeding, remains the key to increased genetic yield potential (Long et al, 2015). Reducing the energy losses during photosynthesis could help improve solar energy conversion efficiency, thereby boosting crop yields (Gu et al, 2014; Furbank et al, 2015; Yin and Struik, 2015). …”

Impaired Stomatal Control Is Associated with Reduced Photosynthetic Physiology in Crop Species Grown at Elevated [CO2]

“…The development of crop species has involved the selection of more productive and faster growing varieties over multiple generations (Evans, 1980; Roche, 2015). These selected varieties often possess greater leaf area rates of P N than their less productive counterparts (Zelitch, 1982; Fischer et al, 1998; Gu et al, 2014). As a result, the vast majority of crops currently cultivated possess active stomatal physiological behavior that permits the levels of G s required to sustain high P N , but also the capacity to respond rapidly to a change in environmental conditions (Kalaji and Nalborczyk, 1991; Haworth et al, 2015; Roche, 2015).…”