天全岩白菜光合特性初探

Photosynthetic Characteristics of B.tianquaninsis J.T.Pan

以天全岩白菜(Bergenia tianquaninsis J.T.Pan)为实验材料,利用Li-6400便携式光合测定系统测定其的光合-光响应数据,并同步测定分析了蒸腾速率(Tr),气孔导度(Cond),胞间CO2浓度(Ci)等光合参数.结果表明:(1)天全岩白菜光饱和点(LSP)为1 267.633μmol·m-2·s-1,补偿点(LCP)为14.293μmol·m-2·s-1,最大净光合速率(Amax)为9.866μmolCO2·m-2·s-1,暗呼吸速率(Rd)为1.134μmolCO2·m-2·s-1,表观量子效率(α)为0.079 mol·mol-1.这些值显示出天全岩白菜是阳性耐荫植物.(2)气孔导度和蒸腾速率随光合有效辐射强度增加而增加;胞间CO2浓度在光合有效辐射强度为0-400μmol·m-2·s-1时随光合有效辐射强度增加而下降,大于400μmol·m-2·s-1时呈缓慢上升趋势;而水分利用效率在光合有效辐射强度为0-400μmol·m-2·s-1时随光合有效辐射强度增加而增加,大于400μmol·m-1·s-1时呈现下降趋势.综上所述,可知在人工栽培天全岩白菜的过程中应选择适当的海拔和荫蔽度均较高的环境.

The light-response of photosynthetic rate of B. tianquaninsis J. T. ble Photosynthesis. The results showed that the light saturation point（LSP）, Pan was measured light compensation by Li -6400 Portapoint（LCP） , max-imum photosynthetic rate （ Am.x） , the apparent quantum yield （or） and the rate of dark respiration （Rd） were 1 267.633μmol·m-2·s-1 14. 293μmol·m-2·s-1, 9.8661a, molCO2· m-2 ·s-1 , 0,079mol ·mol-1 and 1. 134μmol·m-2·s-1 , respectivelyy The net photosynthetic rate, stomatal conductance and transpiration rate increased rapidly with the light intensity inereasing, while cell interval concentration of CO2 decreased. The water use efficiency （WUE） of B. tianquaninsis J. T. Pan varied with the parabola model while the PAR increased. When the PAR reach 400μmol·m-2·s-1, the WUE increased linearly, and then decreased gradually. In a word, B. tianquaninsis J. T. Pan can adapt strongly shade-tolerance. So the B. tianquaninsis J. T. Pan to week light capability and it is a heliophilous plant with strong can be cultivated in the higher elevation and shading habitats.