*2.3. Gas Exchange Parameters*

Different physiological traits including photosynthetic rate (*A*), transpiration rate (*E*), stomatal conductance (*gs*), and internal CO2 concentration (*Ci*) were measured by using an open system, portable infrared gas analyzer (IRGA) (LCA-4 ADC (USA)). The fully expanded young leaves of three plants selected randomly from each pot were used to measure these attributes. Measurements were made between 9:00 a.m. and 10:00 a.m. to opt-out of the effect of high temperature. The following adjustments were made for these measurements; leaf surface area 6.25 cm2, ambient CO2 concentration (326 μmolmol−1), the temperature of the leaf chamber ranged from 31.5 to 37.8 ◦C, ambient pressure (P) 98.2 k Pa, chamber gas flow rate (V) 408 mL min<sup>−</sup>1, the molar flow of air per unit leaf area (Us) 409.5 molm<sup>−</sup>2s−1, the water vapor pressure in the chamber (ref.) ranged 21.2–24 mbar, and PAR at leaf surface was maximum up to 1181 μ mol m<sup>−</sup>2s−1.
