[Effects of salt stress on the contents of chlorophyll and organic solutes in Aeluropus littoralis var. sinensis Debeaux].

Abstract

After seedlings of Aeluropus sinensis var. sinensis Debeaux were treated with different NaCl concentrations (0-200 mmol/L) for 14 days, some physiological indexes were measured. The higher the NaCl concentration, the more the growth of A. sinensis was inhibited. The increase in root/shoot ratio suggests that the shoots are more sensitive to salinity than the roots. The diminished leaf area may reduce the transpiration rate, and the root mainly grew longitudinally, which may help the root to reach the water source under the high salinity conditions. Chl a contents increased, so did Chl b, but the Chl a/Chl b ratio declined, which implies the stimulation of Chl a accepted from NaCl is smaller than that of Chl b. After salt treatment, the organic solute contents increased (P<0.05), the proline, amino acids and soluble sugar contents increased more than organic acids, the increase in soluble carbohydrate may inhibit photosynthesis in feedback. The percentage of sucrose in soluble carbohydrates increased too. Although the organic dry weight of whole plant declined, the proportion of organic dry weight in total dry weight increased, and the osmotic potential of plant cell juice declined, which implies that the contribution of organic matter to osmotic adjustment increased with salinity. That is, A. sinensis had ability to tolerate salinity to a certain degree.