Responses Of Photosynthetic Physiology And Sap Flow To The Introduction Of External Dye In Populus×euramericana Cv.‘74/76’

The exogenous liquid introduction technology is based on the flow of sap and the transpiration of leaves as the driving force or external force to deliver liquids such as pesticides,fungicides,liquid fertilizers and plant growth regulators to the tree.It is a more effective way to promote the value-added poplar wood by changing the wood color by using exogenous liquid introduction technology to introduce dyeing solution into the tree.It is of great significance to enrich the wood color and increase the value of poplar wood by using the technology of introducing dyeing solution to the tree.In this study,The six-year-old 107 poplar(Populus×euramericana cv.’74/76’)was the raw material.The external dye solution introduction technology was used to introduce active red dyeing solutions with the various concentrations and different penetrants into the target trees to study the effects of different concentrations of dyeing solution and the addition of different penetrants on the photosynthetic physiological indexes,sap flow and dyeing effects of Populus×euramericana cv.‘74/76’.I analyzed the relationship between dye absorption and physiological indicators,and screened out the appropriate concentration of dyeing solution and the type of penetrant,providing theoretical basis for the living wood dyeing technology.The results are as follows:1.The dye absorption of each treatment showed an upward trend with the extension of the introduced time,but decreased with the increase of the dye solution concentration.the dyeing rate and the height of 0.2%were higher than 0.6%.The introduced exogenous dyeing solution significantly inhibited the flow rate of the poplar trunks.The 0.2%concentrated liquid was significantly lower than other concentrated liquids(0.4%and 0.6%).The net photosynthetic rate(Pn)and stomatal conductance(Gs)and transpiration rate(Tr)of poplars treated with different concentrations of dye solution treatment were significantly lower than those of the control,and the intercellular CO2 concentration(Ci)decreased first and then increased,and the suppressive effect of 0.4%and 0.2%dye solution on each photosynthetic parameter were higher than 0.6%dye solution.The contents of chlorophyll(a+b),chlorophyll a,and chlorophyll b with three concentrations were significantly lower than those of the original poplar at the later stage of the process.The content of free proline treated with each dyeing solution showed an upward trend and then a downward trend.2.Except for the intercellular carbon dioxide concentration,there was a significant correlation between the physiological indexes and the dye absorption of poplars treated with each concentration of dye solution.The maximum sap flow rate,Pn,Gs,Tr and the content of chlorophyll(a+b)were extremely significantly negatively correlated with the dye absorption.The order of the correlation was Pn,Tr and Gs,the content of chlorophyll(a+b),the maximum sap flow rate.The free proline content had a significant positive correlation with the dye content.3.The dye content of each penetrant treatment was significantly different from each other,which shown that the dye content of peregal O treatment was more than that of penetrating agent JFC treatment and that of rapid penetrating agent T treatment.There was no significant difference in the height of the dyeing liquid treated by each penetrant.The dyeing rates of the mixed dyeing solutions treated with different penetrants were significantly different.The dyeing rates of peregal O,the penetrating agent JFC and rapid penetrating agent T decreased in turn.The introduction of mixed liquids of different penetrants and dyes could inhibit the photosynthesis and transpiration of poplars.The maximum sap flow rate,Pn,Gs,Tr,chlorophyll a,chlorophyll b,and chlorophyll(a+b)content of each treatment showed a downward trend with the introduction of the dye mixture,while Ci showed an increase trend after a decrease.The inhibitory effects of peregal O on sap flow rate and photosynthetic characteristics were greater than those of the penetrating agent JFC.the content of free proline in leaves treated by peregal O showed an upward trend and then a downward trend with the introduction of dye mixture,and the content of free proline treated with the penetrating agent JFC and rapid penetrating agent T showed an upward trend.The dye content also showed an upward trend with time.4.The maximum sap flow rate,Pn,Gs,Tr,and the content of chlorophyll(a+b)of the poplars treated with different penetrants showed a very significantly negative correlation with the dye absorption,and the order of correlation was the content of chlorophyll(a+b),Pn,Tr,Gs,the maximum sap flow rate.Ci,free proline content and the dye absorption were extremely significant and significantly correlated,respectively.5.Comprehensive analysis showed that 0.2%and 0.4%dye solution had better dyeing effect than 0.6%dye solution,but 0.2%dye solution had stronger inhibitory effect on tree physiological activities than 0.4%and 0.6%dye solution,so the dye concentration of 0.4%was suitable as exogenous dye solution to be introduced into the tree for dyeing.Adding peregal O,the penetrating agent JFC and rapid penetrating agent T in 0.4%dyeing solution,the dyeing effect was weakened in sequence,but peregal O treatment had the strongest inhibitory effect on tree physiological activities,so the penetrating agent JFC was the best penetrant added to the dyeing solution.