Response of Physiological and Photosynthetic Indexes of Tropaeolum majus Seedlings under Drought-Salt Stress
Tropaeolum majus was used as a test plant to explore changes in the physiological and photosyn-thetic indexes of Tropaeolum majus seedlings under drought and salt stress.The results showed that with the deepening of NaCl stress,the activity of peroxidase initially increased and then decreased,the content of malon-dialdehyde decreased initially and then increased,and the relative injury rate continued to increase,showing sig-nificant variations at an NaCl concentration of 1.2%.The soluble protein content ranged from 4.93 mg/g to 3.37 mg/g,showing a downward trend.When the concentration of NaCl rose from0.4%to2.0%,the chloro-phyll content,net photosynthetic rate,stomatal conductance,and transpiration rate all continued to decrease,while the intercellular carbon dioxide concentration ranged from 131.67 μmol/mol to 1 227.67 μmol/mol,showing an upward trend.With the increase of drought stress,the activity of peroxidase decreased,whereas the content of malondialdehyde and the relative injury rate increased.The content of soluble protein ranged from 5.09 mg/g to 3.99 mg/g,exhibiting a downward trend.When the drought level increased from mild to severe,chlorophyll content,net photosynthetic rate,stomatal conductance,and transpiration rate all continued to de-cline,and the intercellular carbon dioxide concentration ranged from 487.33 μmol/mol to 761.00 μmol/mol,showing an increasing trend.In conclusion,Tropaeolum majus seedlings have certain resistance to an NaCl con-centration less than 1.2%,and mild drought tolerance.
Tropaeolum majusSalt stressDrought stressPhysiological indexPhotosynthetic index
NETL
NSTL
万方数据
