Effects Of Exogenous Salicylic Acid On Photosynthetic Characteristics And Drought Resistance Of Zanthoxylum Bungeanum

In this paper, ten-year-old plants of DaHongPao were used as experiment materials. By the 1.0mmol·L-1 SA solution was sprayed on the leaves of DaHongPao under natural condition. We measure the photosynthetic characteristics, physiological and Bio-chemical indicators, like MDA, proline content, soluble sugar content, soluble protein content, the activity of peroxidase, catalase activity, superoxide dismutase, superoxide anion production rate. The influences of the physiological and biochemical mechanism on DaHongPao by exogenous SA were discussed. All results are provided the base theory of photosynthetic characteristics and antioxidant ability on DaHongPao. The results are showed that:1. By sprayed the 1.0mmol·L-1SA on the leaves of DaHongPao can improve and the protect photosynthesis structure. Results are showed that salicylic acid could significantly increase transpiration rate and the stomatal conductance of CO2, enlarge the propagation rate of Sub-stomatal CO2, and they are higher than relative CK by 20.5% during the fruit setting stage and 21.8% during expanding growth stage. The average rate of net photosynthetic rate is 9.22μmol·m- 2·s– 1 at the fruit setting stage and is 10.15μmol·m- 2·s– 1 at the expanding growth stage.2. Application of salicylic acid, the DaHongPao single output to achieve 12.6kg, increased production 1.98 kg compared to the comparison, the increased range is 18.64%.3. Application of salicylic acid can increase the contents of proline, soluble sugar and soluble protein have been larger than relative value, and they are higher than relative CK by13.97% and 37.55%,7.46% and16.63%,18.09% and12.71%,indicating that SA improves DaHongPao ability of penetration and mediation, and protecting structure of enzymes and membrane.4.Application of salicylic acid can increase the SOD, POD and APX activity of other antioxidant enzymes, can be removed the reactive oxygen and MDA in time as environmental change in the body of DaHongPao caused by maintain active oxygen production and elimination of dynamic equilibrium, reduce the degree of the peroxidation caused by the environmental change and the damage. However, salicylic acid has little effect on activity of CAT in DaHongPao.In the present work, by sprayed the 1.0mmol·L-1SA on the leaves of DaHongPao, could significantly increase net photosynthetic rate, thus increased the fruit output. And improve osomoregulation ability, activities of antioxidant enzymes. Consequently, SA enforces adaption ability of DaHongPao to environmental changes.