环境地球化学国家重点实验室知识库

Stressful environment such as drought and salinity affects the plant growth and development. This research was conducted to find out growth and photosynthetic threshold values in Orychophragmus violaceus (L.) O. E. Schulz for an appropriate regime to dilute the salted water. O. violaceus was subjected to different treatments of NaCl (NC2.5 : 2.5, NC5 : 5, NC10 : 10) g L-1, Na2SO4 (NS2.5 : 2.5, NS5 : 5, NS10 : 10) g L-1, and mixture of salts (MS1 : 2.5 NaCl + 10 Na2SO4; MS2 : 10 NaCl + 2.5 Na2SO4; MS3 : 5 NaCl + 5 Na2SO4) g L-1 and 0 as control followed by re-watering. Relative performance of stomatal conductivity and photosynthetic activity was found to have significantly affected plant growth under highconcentration salts levels at NC10, NS10, MS1, and MS2, respectively. Growth parameters were stable under slight (NC2.5 and NS2.5) to moderate stress (NC5, NS5, and MS3) conditions due to fact that photosynthetic activities were partially maintained under stimulated carbonic anhydrase activity. Consequently, the increase in net photosynthetic rate was noted under moderate stress condition which was 44.13, 37.07, and 43.01%, respectively. However, O. violaceus was found as salt tolerant up to moderate stress level, and all growth and physiological parameters were recovered during re-watering phases. Relatively, better recovery noticed in net photosynthetic rate under moderate stress levels, and values were 55.62, 65.46, and 50.82%, respectively. Hence, it is suggested that salinity effect in plants could be reduced by re-watering, based on plant physiological characteristics.