The Research On The Effect Of Water Stress On The Physiology Of Four Kinds Of Legume Under The Water Saving Mode

In order to reasonable use of Robinia pseudoacacia L.,Cercis chinensis Bunge, Cassia bicapsularis L., Sophora japonica'Golden stem'and propose the most economical and reasonable irrigation methods in the garden, the effect of soil water stress, the different concentrations of CO2in environment, different light intensity, different season on the physiology of four plants was studied.The growths of Cercis chinensis were suppressed after treated with flooding for5days, and the growths of Robinia pseudoacacia were suppressed after treated with flooding forll days which were embodied in the decreasing of qP, ETR. C. chinensis almost died after treated with flooding for7days and R.pseudoacacia almost died after treated with flooding for19days. The growths of Sophora japonica'Golden stem'were suppressed after treated with flooding for17days, which was embodied in the decreasing of Vcmax, Jmax, TPU,and died after treated with flooding for23days.After treated with flooding for60days, Cassia bicapsularis L. grew well and grew a lot of aerial roots.The slight drought (the water content of soil was between15percent and25percent) was adapt for R. pseudoacacia L., C. chinensis Bunge, C. bicapsularis L.,which was embodied in having the high and stable ETR, net photosynthetic rate and so on in three determination.The water content of soil was between18percent and30percent that was adapt for S. japonica'Golden stem',which was embodied in having the high qP, ETR, Fv/Fm and so on.The mid drought stress (the water content of soil was between8percent and15percent) decreased the growth of R.pseudoacacia L., which was embodied in the decreasing of net photosynthetic rate, the increasing of qN and so on.The long time mid drought stress (the water content of soil was between8percent and15percent) decreased the growth of C. chinensis Bunge, which had the lower qP,ENR, net photosynthetic rate, Trmmol and so on after treated with mid drought stress for11days.The mid drought stress (the water content of soil was between10percent and15percent) decreased the growth of C.bicapsularis L., which was embodied in the decreasing of light saturation point,the maximum photosynthetic, Vcmax, Jmax, TPU after treated for19days and it will suppresse the growth of C. bicapsularis L.when Soil moisture long time below15percent.The mid drought stress (the water content of soil was between8percent and18percent) decreased the growth of S. japonica'Golden stem', which was embodied in the increasing of malondialdehyde (MAD) and soluble sugar, the decreasing of Fv'/Fm' and few leaves turning yellow after treated for19days.The drought stress (the water content of soil remained below10percent) suppressed the growth of R. pseudoacacia L., which was embodied in the decreasing of the maximum photosynthetic and the R. pseudoacacia L.almost died after treated for19days. The drought stress (the water content of soil remained below11.2percent) suppressed the growth of C. chinensis Bunge, which light saturation poin,Vcmax, Jmax,TPU were lower than the Control and so on, died after treated with drought stress for23days. The drought stress (the water content of soil remained below12.8percent) suppressed the growth of C. bicapsularis L.,which was embodied in the maximum photosynthetic only3.964μmol·m-2.s-1and so on after treated for13days died after treated for23days. The drought stress (the water content of soil remained below11.3%percent) suppressed the growth of S. japonica'Golden stem',which was embodied in the light saturation point,a apparently elevated quantum efficiency(a), Vcmax,Jmax,TPU lower than Control group and the maximum photosynthetic only4.484μmol·m-2.s-1.According to the three times determination of the control group, the water content in the soil content above40percent would limit the growth of R. pseudoacacia L.and the water content in the soil content above35percent would limit the growth of C. chinensis Bunge, which was embodied in the decreasing of Fv'/Fm',net photosynthetic rat and so on; The water content in the soil content above36percent would limit the growth of S. japonica'Golden stem', which had the lower light saturation point,the maximum photosynthetic and so on.Effects of the different concentrations of CO2on the light curve of four plants is as follows. The maximum photosynthetic of Robinia pseudoacacia L.and Sophora japonica'Golden stem'were21.559μmol·m-2.s-1,22.312μmol·m-2.s-1respectively, when the CO2concentrations reached1200μmol·mol-1.The maximum photosynthetic of Cercis chinensis Bunge and Cassia bicapsularis L.were26.031μmol·m-2.s-1, 26.688μ.mol-m-2.s-1respectively, when the CO2concentrations reached1600μmol·mol-1.Effects of the different light intensity on the A-Ci curve of four plants is as follows.When the light intensity is800μmol·m-2·s-1, the carboxylation rate,RuBP regeneration rate,the maximum photosynthetic of R.pseudoacacia have the highest value and the maximum photosynthetic up to27.480μmol·m-2·s-1.When the light intensity is2000μmol·m-2·s-1, the carboxylation rate,RuBP regeneration rate,the maximum photosynthetic of C. chinensis Bunge and S.japonica'Golden stem'have the highest value and the maximum photosynthetic were32.407μmol·m-2·s-',30.099μmol·m-2·s-1respectively. When the light intensity is1600μmol·m-2·s-1, the carboxylation rate,RuBP regeneration rate,the maximum photosynthetic of C.bicapsularis have the highest value and the maximum photosynthetic up to28.909μmol·m-2·S-1.Effects of the different season on the The fluorescence parameters,Photosynthetic parameters of four plants are as follows.When daily temperature changes at12℃to21℃,the growths of R. pseudoacacia L. were suppressed, which was embodied in the Fv/Fm lower than the normal range (0.80-0.83).When daily temperature changes at12℃to16℃, the growths of C.chinensis Bunge and S.japonica'Golden stem'were suppressed, which was embodied in the Fv/Fm lower than the normal range.When daily temperature changes at12℃to16℃, the Fv/Fm of C. bicapsularis was in the normal range.We have come to the conclusion:The best irrigation for R. pseudoacacia C.chinensis Bunge were the water content of soil between15percent and25percent in the garden. The best irrigation for C.bicapsularis L.was the water content of soil between18percent and25percent in the garden. The best irrigation for S. japonica Golden stem'.was the water content of soil between18percent and30percent in the garden. It would limit the growth of R.Pseuudoacacia L., C. chinensis Bunge, S.japonica'Golden stem'that the water content in the soil is above40percent a long time. The size of the order of the water logging tolerance of four bush species is C.bicapsularis L.,S.japonica'Golden stem', R.pseudoacacia L., C. chinensis Bunge. the drought-resistent ability of four bush species is R. pseudoacacia L.and C. chinensis Bunge better than S. japonica'Golden stem'and C. bicapsularis L. The size of the order of the high light tolerance of four bush species is C. chinensis Bunge and S. japonica 'Golden stem', C.bicapsularis L., R. pseudoacacia L. The potential photosynthetic capacity of four bush species is C. chinensis Bunge and C. bicapsularis L.better than R. pseudoacacia L. and S.japonica'Golden stem'under the high concentration of CO2condition. The potential photosynthetic capacity of four bush species is C. chinensis Bunge and S.japonica'Golden stem'better than R. pseudoacacia L. and C. bicapsularis L.under the high light condition. It is suitable for four plants growth that the daytime temperature maintain at24℃to33℃during seedling stage. When the intensity of light is above than2000μmol·m-2·s-1,the seedling growth of R. pseudoacacia L.and C.bicapsularis L. were suppressed and it must take some shady measures.