Effects Of Exogenous Sucrose And DA-6 On The Discoloration Of Autumn Leaves Of Three Autumn Tree Species In Liaoning

Autumn foliage plants are an important part of the garden landscape,and they play an irreplaceable role in building a natural landscape environment in urban gardens.Due to the different climatic conditions and other factors in different regions of Liaoning Province,the leaf color expression of autumn leaf plants is also very different.Some leaves have a delayed discoloration time,some have a shorter time of discoloration,and some have a lower degree of discoloration.Greatly reduce the value of autumn foliage tree species in autumn.In this experiment,three autumn leaf tree species,Acer truncatum,Acer rubrum and Ginkgo biloba,which are widely used in various regions of Liaoning Province and are highly liked by people,were used as test materials.The effects of exogenous sucrose solution and plant growth regulator DA-6?diethyl aminoethyl hexanoate?solution on the change of leaf color of three autumn leaf tree species were studied,and the exogenous chemical substances suitable for improving the leaf color of three autumn leaf plants were found.It is used to improve the ornamental value of autumn color-leaf plants in Liaoning area and extend the viewing time of autumn-leaf tree species.In this study,after spraying exogenous sucrose solution and DA-6solution on the leaves of three autumn leaf tree species:A.truncatum,A.rubrum and G.biloba,Obtain the temporal changes of autumn leaf color,temperature and humidity of the test plot,the leaf color model of the sample tree,and the changes in photosynthetic pigment content and flavonoid pigment content during the color change period of autumn leaves with naked eyes,field monitoring and physiological index measurement,Changes in the content of osmotic adjustment substances?soluble sugar,soluble protein?and changes in the activity of antioxidant enzymes?SOD,POD,CAT?,In order to analyze and discuss the changes in leaf color of autumn plants,various physiological indicators of plants,and the influence of the concentration of artificially applied chemical substance solutions on autumn leaf trees,it provides a scientific basis for improving the actual ornamental value of autumn leaf trees in Liaoning.The results of the test are as follows:1.When the leaf discoloration rate of the three autumn leaf tree species in Liaoning is above 60%,they enter the best viewing period.During the experimental observation period,the color model color parameters of A.truncatum L*value?representing light and dark?,b*value?representing yellow and blue?The values of the three color parameters of A.truncatum and A.rubrum all show low-high-low changes,and the a*value of A.truncatum?representing red and green?and the value of the three color parameters of G.biloba are all increased.On October 15th,when the temperature difference between day and night t₃reached 26?,the three plants began to change color,indicating that they have entered a period of leaf color change.After October 20th,the daily minimum temperature t₁in the test site did not exceed8.9?.At this time,the sample tree Change the color completely.From the field monitoring of this experiment,we have reached a conclusion:that a certain lower temperature and temperature difference is beneficial to the discoloration of autumn leaves of the three trees,and suitable moisture can also promote the discoloration of autumn leaves to a certain extent.It is found through field monitoring During the experiment,the average daily humidity h₄in the early stage of the color change of the plants was mostly above 58%.It can be seen that the appropriate air humidity is beneficial to the autumn leaves to form beautiful and beautiful leaves.2.The photosynthetic pigment content of A.truncatum,A.rubrum and G.biloba showed a downward trend during the leaf color change in autumn.The spraying of exogenous sucrose has little effect on the photosynthetic pigment content of the three autumn leaf tree species.The DA-6 solution has no obvious effect on the chlorophyll a and chlorophyll b of the three autumn leaf plants,but it improves the content of the three tree leaves.The carotenoid content is the highest in leaves treated with 30mg/L DA-6 solution.3.The anthocyanin content of A.truncatum,A.rubrum and G.biloba increases during the leaf discoloration period in autumn.Exogenous sucrose has a significant effect on the anthocyanin synthesis of the leaves of the three autumn leaf tree species.Among them,the40mg/L sucrose solution has the most obvious effect,especially the A.rubrum.The anthocyanin content is less than that in the late stage of discoloration.Before discoloration,the control group and the test group increased by 82.21%,155.58%,and 140.4%respectively.DA-6 solution can also increase the anthocyanin content of A.truncatum,A.rubrum and G.biloba,but the effect is not as obvious as exogenous sucrose.4.The soluble sugar content of A.rubrum and G.biloba leaves in autumn showed a single peak curve that first increased and then decreased,while the leaf content of G.biloba increased.40mg/L and 60mg/L exogenous sucrose solutions can increase the soluble sugar content of the leaves of the three tree species,but the spraying of 40mg/L exogenous sucrose solution can make the color expression of the leaves the best and soluble The sugar content value is also the highest.DA-6 has a small effect on the soluble sugar content of A.truncatum and A.rubrum.The 30mg/L DA-6 solution has a good effect on the soluble sugar content of G.biloba leaves.The content of soluble protein in the leaves of A.truncatum and A.rubrum showed a decrease,the leaf content of G.biloba showed a low-high-low change.The spraying of exogenous sucrose solution can inhibit the degradation of the soluble protein content of A.truncatum,A.rubrum and G.biloba.DA-6 solution has inhibitory effect on the degradation of soluble proteins of A.truncatum and G.biloba,and can improve the resistance of plants and make their discoloration period last longer.5.The changes in the activities of superoxide dismutase?SOD?,peroxidase?POD?and catalase?CAT?of A.truncatum and the POD and CAT enzymes of A.rubrum and G.biloba showed an insignificant increase first and then With a declining single-peak curve,the SOD enzymes of A.rubrum and G.biloba both showed a downward trend.Exogenous sucrose can improve the activities of the three antioxidant enzymes of A.truncatum and the POD enzyme and CAT enzyme activities of A.rubrum and G.biloba.The effect of 40mg/L sucrose solution is more obvious.DA-6 solution reduced the SOD enzyme activity of three autumn leaf plants,but 30mg/L DA-6 solution can increase POD enzyme and CAT enzyme activity of A.truncatum,A.rubrum and G.biloba.