| Abstract: | Objective] Study on the photosynthesis and fluorescence characteristics in peony under water stress. Method] The two peony varieties Hu- hong and Luoyanghong were treated by different water stress for determining the photosynthesis and fluorescence characteristics. Result] With the aggra-vation of water stress, the net photosynthetic rate (Pn) and stomatal conductance (Gs) decreased, while the intercellular CO2 concentration (Ci) in-creased. Drought could decrease Pn, constrain gas exchange and change the daily photosynthesis. Fo of peony leaf increased and Fv/Fm decreased under water stress especially water logging, causing the inactivation of the PS II reaction center, and the chlorophyll fluorescence characters gradually recovered until afternoon. Condusion] The 75% soil relative water content (SRWC) is the best condition for growth of peony. Compared with drought, water log- ging is more unfit for the growth of peony. For the two varieties, Huhong assumed more tolerance to drought, accordingly more adaptability. |
