The Effects Of Spermidine And Salicylic Acid On Drought Resistance Of Phyllostachys Edulis Seedlings

With annual Phyllostachys edulis seedlings as test material, under moderate drought stress, different concentrations of spermidine(Spd) and salicylic acid(SA) were watered in phyllostachys edulis seedlings’ root to study the effects of them on drought resistance of phyllostachys edulis seedlings’ physiological and biochemical characteristics. This research can provide theoretical reference to the cultivation management and resistance screening. Main results and conclusions are as follows:Under drought stress, growth of phyllostachys edulis seedlings were limited. Compared with drought control, treatments with Spd and SA increased phyllostachys edulis Seedlings’ biomass and transfered biomass to undergroud. 2.0mmol·L-1 SA had most significant improvements to biomass and root-shoot ratio of seedlings under water stress.Under drought stress, REC and MDA significant increased, and leaf water content of phyllostachys edulis seedlings decreased. Treatments with 1.0mmol·L-1 Spd and 2.0mmol·L-1 SA significantly increase leaf water content, and decrease REC and MDA under water stress.Under drought stress, osmotic adjustment ability of phyllostachys edulis seedlings was strengthened and then weakened. Proline, soluble protein and soluble sugar content increased significantly treated with Spd and SA. These two exogenous substances strengthened osmotic adjustment ability of phyllostachys edulis. After 21 d under drought stress, 1.0mmol·L-1 Spd had more significant improvement on proline than other treatments, which were increased by 175.7% and 83.0% compared with drought and 2.0mmol·L-1 SA.Under drought stress, POD activity of bamboo declined before it was stable, and CAT activity and SOD activity increased significantly in the 7d and 21 d. Under drought stress, antioxidant enzymes are changed and activated. Treatments with Spd and SA had no significant impact on antioxidant enzymes.Under drought stress, photosynthesis of bamboo decreased. Under drought stress, a certain concentration of exogenous Spd and SA could increase chlorophyll contents of bamboo. 1.0mmol·L-1 Spd was most significant in elevating photosynthetic capacity under water stress, which showed up in increasing Pn, WUE, Fv’/Fm’, ΦPSII and ETR.Under drought stress, treatments with 1.0mmol·L-1 Spd and 2.0mmol·L-1 SA could effectively improved drought adaptability of Phyllostachys edulis seedlings by increasing their root system, reducing water loss, and improving the osmotic regulation ability and photosynthetic capacity, etc. Treatment 1.0mmol·L-1 Spd had the most comprehensive effect on phyllostachys edulis seedlings under water stress.