Abstract
Rice (Oryza sativa L.) is the second largest cereal crop produced globally, with a worldwide production of about 720 million metric tons in recent years and contributing toward for 20% of the global calorie intake. The growing condition of rice is extreme such as high vs. low temperature and high vs. low level of CO2 concentration [CO2]. Given CO2 is a key substrate for photosynthesis, the atmospheric concentration of CO2 dominantly influences the growth and yield of rice crop. The main component of rice is the kernel (~90%) which is starch, and the composition and behavior of starch are greatly impacted by environmental drivers including temperature, CO2, and water. Therefore, it is important to understand the variation in production and yield of rice under the elevated [CO2]. Here, we discussed the impacts of elevated [CO2] on the quality and quantity of rice production under current and future climatic conditions. We have discussed the response of rice crops under elevated [CO2] and its interaction with several other biophysical drivers including air temperature, ozone concentration, soil water content, and genotype in various experimental approaches, viz., free-air CO2 enrichment (FACE), open top chambers (OTC), growth chambers, and temperature gradient tunnels. Overall, elevated [CO2] stimulated photosynthesis and production of rice on a short-term, but the long-term effects of elevated [CO2] on the quality and quantity of rice production is yet to be resolved and need some attention with respect to various environmental constraints.
