Effect Of Soil Natural Water Stress On Physiological And Biochemical Indexes In Parthenocissus Tricuspidata Seedling

Based on ivy(Parthenocissus Tricuspidata) as test materials, take annual seedlings whose plant height, leaf quantity and root morphology is basically the same for potted drought test. Study on soil natural water stress P. Tricuspidata seedling circumstance, the changes of physiological and biochemical indexes. Research results show:1.Under water stress, the relative water content of leaves, leaf water potential and soil moisture content in P. Tricuspidata is gradually declining trend, water saturation deficit is gradually increasing. Among the relative water content of leaves and potential in the prophase of water stress were higher level, but in the soil moisture content, then fell rapidly stress remained relatively stable.2.Under water stress, P. Tricuspidata seedling conductivity and MDA content overall rising.In the medium-term stress, electric conductivity and MDA in change is not significant, water stress 21 days, electric conductivity and MDA content is rising rapidly.Analysis shows that P. Tricuspidata has strong drought resistance, and the water stress 21 days for P. Tricuspidata seedling damage of membrane.3.under water stress, the content of proline, soluble sugar, soluble protein in P. Tricuspidata seedling all present gradually increasing.In the 21 days prior to the stress, soluble sugar content increases larger, after change tends to gently, difference was not significant.Free proline content is not significant changes in the stress, after 21 days, free proline content increases rapidly, the more serious the more rapidly increasing.Variance analysis showed that when 21 d stress the level is 0.05 significant difference.P. Tricuspidata seedlings leaf osmoregulation substance increased, explain that P. Tricuspidata has a strong drought resistance.4.Under water stress, SOD activity first increased, then decreased;After the first reduce POD activity increased;The CAT activity is gradually increasing and downturn in the late stress.And SOD activity in 21 days with POD by peak, then the protective enzyme activity began to drop.21d stress is that protect enzymes of P. Tricuspidata changing threshold, over the threshold, the drought of plant itself will reduce, thus affect plant growth.Therefore want to normal growth, P. Tricuspidata seedlings under water stress were 21 days for critical value.5.Correlation analysis showed that in the middle of water stress, the leaf of soluble protein in P. Tricuspidata is active, It and the relative water content of leaves, leaf water potential, MDA and proline are showed significant correlation.In the late stress, the indexes in the correlation between obvious strengthening.SOD, POD and CAT significant correlation, three enzymes mutual interaction enhanced plant body first bud enzyme system of drought.The process of water stress each index complement each other, synergy effect so as to reduce the damage to plant drought.The-refore, can explain P. Tricuspidata is strong resistance of plants. Principal component analysis, In this study of 11 physiochemical index, the first principal component of the relative water content, water potential, leaf electrionic conductivity and the second principal components of POD activity, are mainly ability index of close relationship with ivy.