镉对超富集植物滇苦菜(Picris divaricata Vant.)光合及叶绿素荧光特性的影响

Growth, photosynthesis, chlorophyll fluorescence characteristics in leaves of Zn/Cd hyperaccumulator Picris divaricata Vant. were investigated under different cadmium treatments. Low Cd treatments stimulated plants＇ growth and high treatments inhibited it. And Net photosynthetic rate reached maximum at 5μM Cd and stomatal conductance, intercellular CO2 concentration and transpiration rate decreased while stomatal limitation value increased with the increasing Cd. Cd did not affect chlorophyll fluorescence parameters Fv/Fm、ФPSⅡ and ETR significantly, which indicated that PSII and electron transport chain were not greatly damaged by Cd. qP firstly increased and later decreased with increasing Cd, while the trend of qN was opposite to qP. It suggested that with the increasing Cd, the harvested light energy couldn＇t be dissipated efficiently by light reaction and the ratio of excitation energy dissipation as heat increased.?Light reaction of photosynthesis in hyperaccumulator Picris divaricata?showed great torelence to Cd.?And Cd may affect stomatal and thus influence the net photosynthetic rate in Picris divaricata.