Carbon dioxide responsiveness mitigates rice yield loss under high night temperature

Area of Science:

• Agricultural Science
• Plant Physiology
• Climate Change Biology

Background:

• Rising night-time temperatures pose a significant threat to global rice production.
• Elevated atmospheric carbon dioxide ([CO2]) levels interact with high night temperatures (HNT), impacting crop yields.

Purpose of the Study:

• To identify [CO2] responsiveness in a diverse indica rice panel under varying conditions.
• To assess the impact of elevated [CO2] (e[CO2]) and HNT on rice yield and physiological traits.

Main Methods:

• Field experiments with 194 indica rice genotypes in 2016, varying planting densities.
• Free-air [CO2] enrichment (FACE) facility used in 2017 with 23 genotypes.
• Testing promising genotypes under HNT and e[CO2] + HNT conditions in 2018.

Main Results:

• Low planting density showed a strong relationship with e[CO2] responsiveness (R2 = 0.71).
• High [CO2] responsive (HCR) genotypes exhibited significantly less negative impact from HNT compared to low responsive genotypes.
• [CO2] responsiveness was a key factor in maintaining grain yield and components in HCR genotypes, with minimal yield loss under HNT.

Conclusions:

• Active selection and breeding for [CO2] responsiveness can compensate for HNT-induced yield losses in rice.
• This strategy is crucial for sustaining rice production under current and future warmer climates.
• Findings may also apply to other C3 crops facing similar climate challenges.