Photosynthesis and growth responses of peanut (Arachis hypogaea L.) to salinity at elevated CO2

Abstract

Four peanut (Arachis hypogaea L.) cultivars (cvs. TPT-1, TPT-4, JL-24 and TMV-2) were grown in open-top chambers at 350 and 600 µmol CO2/mol in soil amended with 0 (control), 50, 100 and 200 mmol solutions of NaCl. The net photosynthetic rate (Pn), stomatal conductance (gs), transpiration (E) and dry biomass of leaf, stem and root were measured on 60 days after sowing. The plant growth and photosynthesis increased in both NaCl treated and control plants with elevated CO2. The gs and E decreased under elevated CO2 and the CO2 effect was highly significant under salt stress mitigating the adverse effect on these components in all the four cultivars tested. A positive correlation was observed between Pn and dry biomass under elevated CO2 and salt stress. Enhanced CO2 helps to increase growth and photosynthesis in peanut cultivars and it ameliorates the adverse effects induced by salt stress.

Keywords

• elevated carbon dioxide
• net assimilation
• stomatal conductance
• nacl
• legume