Effect of multigenerational exposure to elevated atmospheric CO2 concentration on grain quality in wheat

Abstract

Many studies have focused on the effect of elevated atmospheric CO2 concentration (e[CO2]) on grain yield and quality in wheat intrageneration; however, the long-term effect of e[CO2] over multiple generations, which will be the case for crops grown in future climate, has received little attention. The grain yield and quality were investigated in wheat after one generation (F1 harvested in 2014) and four generations (F4 harvested in 2017) successively grown in ambient CO2 concentration (a[CO2], 400 μmol L−1) and e[CO2] (800 μmol L−1), respectively. It was found that the shoot biomass and grain yield were enhanced by e[CO2], whereas the increases of grain number and shoot biomass were more pronounced in F4 compared with that in F1, indicating intergenerational additive effect of e[CO2] on these variables. In relation to F1 plants, the exposure to e[CO2] over four generations caused larger reduction in grain N, K, Ca, protein, GMP and total amino acid concentrations, though the starch yield were not significantly affected. The results indicate that multigenerational exposure to e[CO2] could further enhance grain yield but exacerbate grain quality reduction in wheat, and the short-term plant response to e[CO2] would not be capable of predicting long-term response of wheat crops to a future CO2-enriched environment.