Study On The Physiolocal Characters Of Leaf Color Expression Of Colored-Leaf Trees Introducted In Shanghai

Photosynthesis directly influences the growth speed and leaf pigment content, and further affects the color expression of leaves of the colored-leaf trees. So it has important theoretical value and realistic significance to study on the photosynthesis and color expression of colored-leaf trees. In this paper, used one of nursing variety of Acer L. -Acer palmatum'Bloodgood' as material, we measured the light response curve, CO₂ response curve, temperature response curve, Diurnal variation of photosynthetic characters, pigment content, and so on, and discussed the physiological characters of color expression of leaves in tree. The results showed that:1. Light response curveThe light compensate and saturated points were 32.66μmol·m^-2·s^-1 and 1260μmol·m^-2·s^-1 respectively, the apparent quantum efficiency was 0.0197, it likes light very much and must be planted in light-enough place.2. CO₂ and temperature response curves(l)The CO₂ compensate and saturated points were 49.34μmol·m^-2·s^-1 and 991.67μmol·m^-2·s^-1 respectively, the carboxylating efficiency is 0.0116, it was fit to the large-scale CO₂ strength changing, but it was have the lower CO₂ strength utilization;(2)The adaptive temperature 5⁴0℃ and the proper temperature for photosynthesis was 25²7℃.3. The diurnal variation of photosynthesis(l)The diurnal variation of Pn was "two-peak-type", Pn was reduced remarkably in summer noontime and appeared remarkable "noon-drop" phenomenon;(2)Shading was reduced the diurnal Pn;(3)Diurnal variation of Pn was: blue light was highest and then green light, red light lowest in three kinds of lights, it was have higher utility in blue light;(4)Diurnal variation of Pn was: natural water soil was hightest and then light drought, heavy drought lowest in three kinds of soil water.4. Variation of leaves pigment content under different environment(l)The weaker the light became, the more the anthocyanin-content of leaves was, meanwhile the contents of sugar and the starch were decreasing;variance analysis showed that the light level was effected remarkably on the chlorophyll, anthocyanin and carbohydrate and unremarkably on the carotenoid;Correlate analysis also showed that there were positive correlation between plastid pigments and sugar, but negative correlation with plastid pigments;(2)Under the red and blue light, the chlorophy II and carbohydrate content were higher;the contents of anthocyanin, sugar and starch were higher in the blue light;showed that visible light affected anthocyanin, same with blue light, and blue light was in favor of the accumulation of the anthocyanin and carbohydrate;variance analysis and multiple comparisonshowed that light quality affected remarkably to the content of the anthocyanin and starch;(3)In the three water soil, contents of plastid pigment of leaves was: natural water soil was hightest and then light drought, heavy drought was lowest and contents of anthocyanin, sugar, and starch were: light drought was hightest and then natural water soil, heavy droughtwas the lowest, light drought was in favor of the accumulation of the anthocyanin.