The Effect Of S3307, DA-6and Extraneous Soucres On Leaf Color Of Acer×freemanii And Acer Palmatum Thunb

With the review of the mechanism of change in leaf color and the summary of influence of environmental factors and plant growth substances to Aceraceae’ leaf color, this dissertation studies the effects of exogenous sucrose solution and two kinds of plant growth substances on Acer xfreemanii and Acer palmatum Thunb’s leaf color change. The aim of this dissertation is improving condition of colorful leaf in autumn, increasing the aesthetic value of maple and extending appreciating period. After the use of uniconazole and spraying different concentrations of DA-6and sucrose solution, the chronological order of the leaf color change, leaf color model, chlorophyll content, carotenoid and anthocyanin content, soluble sugar content, POD and PAL enzyme activity have been analysised. The results are as followsed.1. The maples enter the best viewing period when its leaf discoloration rate reached60%. Uniconazole and DA-6postponed the best viewing period, but exogenous sucrose can make the best viewing period of Acer xfreemanii and Acer palmatum Thunb in advance.2. Uniconazole, DA-6and exogenous sucrose influence the leaf color parameters of Acer xfreemanii and Acer palmatum Thunb. Uniconazole make parameter L of these maples increased first and then decreased. The color parameter a is always lower than which of CK, while the color parameter b in EG is always higher than the parameter b in CK. The parameter L increased by DA-6which reduce the value of parameter a.Exogenous sucrose reduce the parameter L of these maple,it also enhance the value of parameter a and parameter b.3. Chlorophyll content of Acer xfreemanii and Acer palmatum Thunb decreased in autumn. The uniconazole uniconazole and DA-6significantly improves the photo synthetic pigment content of two kinds of maple. Use of300mg uniconzole has the most significant influence of chlorophyll degradation, and the maple which treated by30mg-L"1DA-6have the highest chlorophyll content. Uniconazole and DA-6also increased the carotenoid content.200mg,300mg uniconazole,20mg-L-1DA-6increase the carotenoid content in different time periods. No effect of exogenous sucrose on the photosynthetic pigments.4. Anthocyanin and soluble sugar content of Acer xfreemanii and Acer palmatum Thunb increased in autumn. The uniconazole can change anthocyanin content and soluble sugar content which first decreased and then increased.DA-6had no effect on the anthocyanin content of Acerxfreemanii, but reduced the anthocyanin content of Acer palmatum Thunb, the30mg-L-1DA-6has the most obvious effect.DA-6also increased the content of soluble sugar. the40mg-L"1and70mg-L-1exogenous sucrose has the most obvious effect.5. The POD activity of Acer×freemanii changes as a single peak curve, however, the POD activity of Acer palmatum Thunb change as a bimodal curve. Uniconazole and DA-6can increase the POD activity, but exogenous sucrose has nonsignificant effect on POD activity.6. PAL activity of Acer xfreemanii showing the trend of increasing and then decreasing, and this trend is positively correlated with anthocyanin content.Uniconazole and exogenous sucrose can’t change the PAL activity of Acerxfreemanii, however, DA-6can reduce the PAL activity.Inhibition of PAL activity by10mg-L-1and30mg-L-1DA-6is most obvious, and the maple which treated by30mg-L-1DA-6have the lowest PAL enzyme activity.