The Effect Of Drought Stress On Growth And Physiological Characteristics Of Sassafras Tsumu Seedlings

To explore the influence of drought stress on the growth and physiological characteristics of Sassafras tsumu, taking one-year-old seedlings of Sassafras tsumu as test materials. The test is simulated natural conditions of drought stress measurement and analysis of the main physiological and biochemical indicators in order to preliminary identification the drought stress resistance of Sassafras tsumu. The main results were as follows:(1)Drought stress all parts of Sassafras tsumu biomass growth have certain inhibition, Sassafras tsumu seedlings root-shoot ratio with drought stress intensifies shows ascendant trend, as water stress intensifies, Sassafras tsumu seedlings’ the relative electrical conductivity of leaf increased and the relative water content decreased.(2) Under drought stress, the content of photosynthetic pigment, POD and SOD activity,proline content,soluble protein content, soluble sugar content kept rising-decline. The plant normal growth was affected by the stress.Drought stress the cytoplasmic caused Sassafras tsumu blade increases membrane permeability,the structure of cell was destroyed in the later,the MDA content of Sassafras tsumu seedlings kept decline-rise-decline.(3)Along with increasing drought stress,Sassafras tsumu leaf photosynthetic rate gradually reduced,at the same time Ci,GS,Tr and all appear to reduce trend,but Ci rised a little in the later.Under drought stress,Sassafras tsumu blade Fm,Fv/Fm,Fv/Fo and qP are tending to reduce the trend,qN are relatively stable.Under drought stress Sassafras tsumu chlorophyll fluorescence properties photosynthetic characteristic and is highly part index linear correlation between qN and other indicators,except for the present negative correlation,other indicators have higher linear positive correlation.The result indicated that under drought stress,Sassafras tsumu were sensitive to the dry soil condition.The dry-resistance of Sassafras tsumu seedlings was weak,and it could only adapt to a slight drought stress within a short term.