Effects Of Drought Stress On Physiological And Characteristics Of Jinsha Pomelo

Pot experiments were carried out to study the effects of drought stress on photosynthetic characteristics, chlorophyll fluorescence parameters and physiological and physiochemical changes of Jinshapomelo leaves. The main conclusions were as follows:(1)drought stress treatment for 50 days, using Li-6400 X portable photosynthetic apparatus measure contrast(CK), light water stress(LS), severe water stress(SS), 3 drought stress treatment s’ photosynthesis. Results show that: compared with CK, chlorophyll content of LS and SS treatment of Jinshapomelo leaf were decreased significantly, while the ratio of chlorophyll a and chlorophyll b was significantly increased; LS treatment of net photosynthetic rate(Pn), stomatal conductance(GS), and intercellular CO2 concentration(Ci), transpiration rate(Tr) and photosynthetic electron transport rate(ETR) compared with the control, there was no significant difference in the overall. However, Pn, Gs, Ci and Tr of SS treatment is decreased significantly, ETR increased significantly, which indicatd that when the water condition is not conducive to the growth of Jinshapomelo,timely need irrigation.Using fluorescence modulation system IMAGING-PAM fluorescence measure the chlorophyll fluorescence parameter under 50 days drought stress, the study results show that compared with CK, the effect of LS stress of Jinshapomelo’s Fv / FM, qN, qP, ETR is not obvious, but SS stress’ s is significantly decreased.The influence of physiological and physiochemical and malondialdehyde(MDA)content of Jinshapomelo leaf after 20 and 50 days drought stress treatments were studied.The results showed that the physiological indexes of all treatments were changed to some extent with the test time. Under SS stress, the actitvity of superoxide dismutase(SOD) was increased with the increase of drought stress, the activity of catalase(CAT) decreased, the water content of leaves decreased, and the synthesis of MDA, proline, soluble protein and soluble sugar was promoted. LS treatment had no significant effect on physiological and physiochemical.