Leaf photosynthesis and yield components of mung bean under fully open-air elevated [CO2]

Abstract

Mung bean (Vigna radiata L.) has the potential to establish symbiosis with rhizobia, and symbiotic association of soil micro flora may facilitate the photosynthesis and plant growth response to elevated [CO2]. Mung bean was grown at either ambient CO2 400 μmol mol-1 or [CO2] ((550±17) μmol mol-1) under free air carbon dioxide enrichment (FACE) experimental facility in North China. Elevated [CO2] increased net photosynthetic rate (Pn), water use efficiency (WUE) and the non-photochemical quenching (NPQ) of upper most fully-expanded leaves, but decreased stomatal conductance (Gs), intrinsic efficiency of PSII (Fv'/Fm'), quantum yield of PSII (ϕPSII) and proportion of open PSII reaction centers..