Department of Horticulture and Biotechnology, Chinese Culture University, Taipei11114, Taiwan.
*Corresponding author’s E-mail: hmy6@nchu.edu.tw
**Department of Life Sciences, National Chung Hsing University, Taichung40227, Taiwan
***National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei11221, Taiwan
Online published on 19 October, 2020.
The effects of water stress on photosynthetic pigments and secondary metabolites of two varieties of greenand purple-leaf Perilla frutescens plants were studied. Plants were grown in plastic pots for 14 days followedby water stress treatment for 10 days in a greenhouse. The trends and rates of soil water potential (SWP), leafwater content (LWC), and the maximum photochemical quantum yield (Fv/Fm) values in these two varietieswere similar as the period of water stress increased from 1 to 8 days. The responses of SWP, LWC, and Fv/Fmvalues to water stress treatment of both varieties were adapted to a water stress period of 4 days. Purple plantsexhibited significantly higher levels of anthocyanins and flavonoids than green plants under drought conditions.However, chlorophyll (Chl) a + b and carotenoids (Car) in the two varieties showed no significant differences inall water-depletion periods. The adjusted normalized difference vegetation index was significantly correlatedwith leaf Chl a+b, and the photochemical reflectance index was significantly correlated with Car in both species,and these can be used as indicators to characterize the physiology of these plants.
Chlorophyll fluorescence, Drought, Photosynthesis, Spectral reflectance, Water stress tolerance
