【摘要】 以林窗、林缘、林阴生境多花黄精（Polygonatum cyrtonema Hua）为研究对象,通过研究其光合和叶绿素荧光特征,揭示其在林下环境的适应机制。选择长势基本一致的3年生多花黄精,测定其光合参数净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）、表观量子效率（AQY）、暗呼吸速率（R_d）、最大光合速率(P_nmax)、光补偿点（LCP）、光饱和点（LSP）和叶绿素荧光动力学参数初始荧光（F_o）、最大荧光（F_m）、可变荧光（F_v）、光化学淬灭系数（qP）、实际光化学量子效率（φPSⅡ）、非光化学淬灭系数（NPQ）、电子传递速率（ETR）、最大光化学效率（F_v/Fm）、PSⅡ潜在活性（F_v/F_o）、pSⅡ有效光化学效率（F’/F_m’）。结果表明,不同生境多花黄精确P_n、T_r、G_s、F_o、Fm、F_v、F_v/F_m、F_v/F_o、F’_v/F’_m差异显著,以林窗最大;LSP、LCP、P_nmax均表现为林窗>林缘>林阴,林窗多花黄精的LSP、LCP、P_nmax分别为1 256、17、6.10μmol/（m²·s）;qP与φPSⅡ变化趋势一致,随着PAR的增大均呈下降趋势;NRQ随着PAR的增大呈增大趋势;ETR随着PAR的增大呈先增大后减小的趋势。多花黄精在林下生境生长均未受到抑制,但其光合和叶绿素荧光特征存在显著差异,表现为林窗更有利于多花黄精有机物质的积累。更多还原

【Abstract】 The photosynthetic and chlorophyll fluorescence characteristics of Polygonatum cyrtonema Hua in forest gap（FG）,forest edge（FE） and forest canopy（FC） were studied to reveal its adaptation mechanism.The 3-year-old Polygonatum cyrtonema Hua with basically the same growth was selected.The photosynthetic parameters including the net photosynthetic rate（P_n）,transpiration rate（T_r） and stomatal conductance（G_s）,apparent quantum efficiency（AQY）,dark respiration rate（R_d）,maximum photosynthetic rate(P_nmax),light compensation point（LCP） and light saturation point（LSP）,as well as chlorophyll fluorescence kinetic parameters including the initial fluorescence（F_o）,the maximum fluorescence（Fm）,the variable fluorescence（F_v）,the photochemical quenching coefficient（qP）,photochemical quantum efficiency（φPSⅡ）,non-photochemical quenching coefficient（NPQ）,electron transfer rate（ETR）,the maximal photochemical efficiency（F_v/F_m）,the potential activity of PS Ⅱ（F_v/F_o）,and the effective quantum efficiency of PS Ⅱ（F’_v/F"_m）,were measured by LI-6800.The results showed there were significant differences in P_n,Tr,G_s,F_o,F_m,F_v,F_v/Fm,F_v/F_o,F’_v/F’_m of Polygonatum cyrtonema Hua in different habitats,their values of Polygonatum cyrtonema Hua in FG were the largest.The P_nmax,LCP and LSP of Polygonatum cyrtonema Hua in different habitats were different too,the order of values was FG>FE>FC.The LSP,LCP,P_nmax of Polygonatum cyrtonema Hua in FG were 1 256,17,6.10 πmol/（m²·s）,respectively.The trend of qP and cpPSⅡ was consistent,which decreased with the increase of PAR;NPQ increased with the increase of PAR.ETR increased first and then decreased with the increase of PAR.The growth of Polygonatum cyrtonema Hua in understory habitats light condition was not inhibited.However,there were significant differences in photosynthesis and chlorophyll fluorescence characteristics,which showed that Polygonatum cyrtonema Hua in FG was more conducive to the accumulation of organic matter.更多还原