The Effect of Salinity on Gas Exchange on Different Developmental Stages of Mung Bean (Vigna radiata L. Wilczek)

In this study, we have put in a experimental pot, a plant of Mung bean (Vigna radiata L. Wilczek), this latest is subjected to salinity stress (NaCl + CaCl2) during four stages of its growth (juvenile stage (5 leaves), flowering stage, after flowering stage and pod setting). Three concentrations of salt solution 100, 200 and 300 meq L-1 and the control (Hoagland solution) were used in irrigation. Exchangeable oxygen was determined in leaf discs and isolated chloroplasts of the stressed plants during respiration and photosynthesis processes. Results indicated that the quantity of the exchangeable oxygen during respiration increases with the increase of salinity concentration. Contrarily, the exchangeable oxygen during photosynthesis decreased with increasing salinity concentration.