Effects of Abscisic Acid on Photosynthetic Characteristics of Radish under Aluminum Stress

A pot experiment was conducted to study the effects of exogenous abscisic acid (ABA) on photosynthetic characteristics of radish under aluminum (Al) stress. Five treatments were used in the experiment: seeds were soaked with 0 (CK), 1, 5, 10 and 20 mu mol.L-1 concentrations of abscisic acid solution. The results showed that abscisic acid enhanced net photosynthetic rate (Pn) of radish significantly. With the increasing of abscisic acid concentration, Pn of radish was enhanced significantly, and when the concentration was 10 mu mol.L-1, Pn of radish reached the highest. The result of transpiration rate (Tr), light use efficiency (LUE) and water use efficiency (WUE) were the same as Pn. However when concentration of abscisic acid is too high, Gs of radish decreased. Soaking different concentrations of abscisic acid on radish under aluminum stress has not significant effect on CO2 concentration of intercellular (Ci). Therefore, abscisic acid could use to enhance the photosynthetic ability of radish, which would help to improve the adaptability of radish, and the best concentration of melatonin was 10 mu mol.L-1.