%0 Journal Article
%T Physiological responses of 2-year-old Acer davidii seedlings to short-term enhanced UV-B radiation<br>短期增强UV-B辐射对青榨槭幼苗生理特性的影响
%A ZUO Yuanyuan
%A LIU Qing
%A LIN Bo
%A HE Hai
%A <br>左园园
%A 刘庆
%A 林波
%A 何海
%J 应用生态学报
%D 2005
%I 
%X At the Maoxian Ecological Experimental Station of Chinese Academy of Sciences in northwest Sichuan Province, 2-year-old native maple(Acer davidii) seedlings were potted outdoors with enhanced UV-B radiation(280 - 320 nm) of 0.27 W x m(-2) (7.7 kJ x m(-2) x d(-1)), which was approximated to the predicted enhanced UV-B reaching the earth surface when stratosphere ozone was depleted by 15% in the local area, with the control plant received ambient UV-B. The gas exchange index and chlorophyll fluorescence, and the contents of chlorophyll and UV-absorbing compounds were examined after 50 days of the radiation. The results showed that enhanced UV-B radiation significantly lowered the maximal net photosynthetic rate (CK = 6.214, TR = 4.452), raised the dark respiration rate(CK = 0.413, TR = 1.295) and light compensation point (CK = 21.629, TR = 59.861), but had little effect on quantum yield (CK = 0.021, TR = 0.032). Under enhanced UV-B radiation, the diurnal changes in net photosynthetic rate, water use efficiency, quantum efficiency of photosystem II centers (Fv/Fm), and quantum yield of photosystem II photochemistry (phi(pspi)) were reduced, chlorophyll a, total chlorophylls, and chlorophyll a/b (CK= 16.23, 5.39, TR = 13.17, 4.93) were also markedly reduced, but chlorophyll b remained nearly unchanged. Contrary to the previous studies, enhanced UV-B radiation decreased the content of UV-absorbing compounds (CK = 0.87, TR = 0.79) in 2-year-old Acer davidii seedling leaves, indicating that the measurement of leaf UV-B absorbing compounds didn't necessarily provide a good indicator of plant tolerance to UV-B. It could be concluded that enhanced UV-B radiation had some inhibitory effects on the photosynthesis of Acer davidii seedlings. Long-term researches are necessary to confirm this conclusion.
%K UV-B radiation
%K Acer davidii
%K Physiological response<br>UV-B辐射
%K 青榨槭
%K 生理生态
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=42FEDDFE54F8BCD9D5FD1926ABDD7722&aid=308FE1F73798CEC3&yid=2DD7160C83D0ACED&vid=7801E6FC5AE9020C&iid=9CF7A0430CBB2DFD&sid=BFDA25D5ECAB4246&eid=0D56350A4FA1FCC9&journal_id=1001-9332&journal_name=应用生态学报&referenced_num=3&reference_num=29