Seasonal Variation of Some Bioactive Compounds and Physiological Characteristics in Peony (Paeonia lactifl ora Pall.)

We determined the phenolic and total flavonoid contents and some physiological characteristics (water potential, chlorophyll fluorescence, chlorophyll index) of Paeonia lactiflora Pall., growing in the Botanical Garden, Mongolian Academy of Sciences. Cultivated plants were harvested at the beginning of vegetation (May), flowering (June), seed formation (July), seed dispersal (August) and end of vegetation season (September). Phenolic content in leaf and stem was increased during the vegetation period and the highest level was reached during the seed formation stage, and it decreased at the end of the vegetation stage. On the contrary, the total flavonoid content in leaf and stem is decreased linearly as the development stages advanced and the highest level was observed at the flowering stage. Variations of water potential, chlorophyll fluorescence and chlorophyll index of cultivated P. lactiflora, increase at the beginning of vegetation and flowering stages, and decrease from seed formation stage to end of the vegetation stage.