The Influence Of Water Stress On Physiological And Biochemical Characteristics Of Camellia Fluviatilis

Camellia fluviatilis is a shrub or small tree of Theaceae,Camellia,Sect.Paracamellia Sealy Rev.In this study,Camellia fluviatilis as experimental material,through artificial simulation of submergence stress,three levels of soil water content named CK,S1and S2 were set up in this study,while CK as control level,S1 means the soil moisture was under saturation state and S2 means the soil moisture was under super-saturation state,two levels of drought stress content named CK and G were set up in this study,while CK as control level,G means natural drought,and rehydration of plants after drought for different periods of time.Determination of plant physiology,photosynthetic and fluorescence index,the measured data were analysis through the comparison of multiple comparisons,correlation analysis and principal component analysis,in order to provide reference for cultivation and landscape application of Camellia fluviatilis.The results were as follows:?1?Under waterlogging stress,appreciation of Camellia fluviatilis was not affected.In the whole water flooded stage,the leaf type and leaf color changed slowly,and only a small amount of yellowing and abscission occurred in the middle and late stage of water flooding.The physiological indexes could be changed to resist the stress environment.The physiological indexes could be changed to resist the stress environment.The chlorophyll content of S1 and S2 showed volatility;SOD activity,soluble protein content and MDA content showed an upward trend,Then a slight decline;The soluble sugar content decreased first and then increased gradually.This shows that Camellia fluviatilis has a good ability to adapt to the flooded environment.?2?Under drought stress,the leaf type and leaf color of Camellia fluviatilis had obvious change,the damage degree increases gradually with the stress time.At the end of the drought,plant damage was more serious.It can be concluded that there are significant influences of drought stress on the appearance of Camellia fluviatilis.Soil water content and relative water content showed a downward trend,and water saturation deficit increased.It showed that the degree of stress increased,the water absorbed by plants from the soil was less and less,and the relative water content of leaves decreased,but from a slow decline trend,it can be seen that the plants adapt to adversity gradually.In physiological aspect,with the extension of drought damage time,the degree of injury deepened,and there were different changes in physiological indexes.In the leaves of Camellia fluviatilis,chlorophyll content,soluble sugar content showed a trend of increased first and then decreased;SOD activity decreased first and then increased;the content of soluble protein decreased;the content of MDA and proline increased.In the aspect of the photosynthetic indexes,Pn,Gs,Tr of Camellia fluviatilis were decreased;C i showed a trend of first increase and then decrease.However,the four photosynthetic indexes were reduced to negative value in the middle and later stage of drought,and the water use efficiency was in an upward trend.This shows that the photosynthetic index can promptly reflect the state of Camellia fluviatilis under drought stress condition,and the photosynthesis of plants under drought stress was seriously affected.In the later stage of drought,Pn,Gs,Tr,C i reduced to negative value,and Camellia fluviatilis can not have normal photosynthesis.In the aspect of the fluorescence index,In the leaves of Camellia fluviatilis,F₀increased;Fm,Fv/Fm showed a downward trend;?PSII?qP increased first and then decreased,NPQ increased first and then declined.The changes of these 6 indicators reflect that the indicators of plants respond to adverse environment through direct and indirect interaction and influence under drought stress.?3?For different days of Camellia fluviatilis of rewatering,the index of recovery varies.At the same time,from the change of the indexes after rewatering,the less the number of days of drought,the plants can return better to normal growth and physiological state in a short time.On the contrary,the longer the drought.The higher the degree of injury,the ability to restore the decline in varying degrees.