Dynamic studies on photosynthetic characteristics and growth development of Perilla frutescens / 中草药

ABSTRACT

Objective: To provide basic theory for rational cultivation and comprehensive utilization of Perilla frutescens. Methods: The photosynthesis and growth characteristics were measured every 25 d from July 10th, 2013. Results: Logistic equation of dry matter weight was firstly established, and the slightly increasing stage was also called seedling stage (0-75 d); The flower budding stage was 76-84 d, the blooming stage was 85-95 d, and the 20 d was called period of accelerating growth stage; The period of decelerating growth was defoliation period (96-125 d). As was observed both specimens "a" and "b", chlorophyll content increased and reached the peak value during flower budding before going on a gradual decline, but not before that of soluble proteins. The Hill reaction, as well as Ca2+-ATPase and Mg2+-ATPase activities all reached the peak values just before blooming began; The photosynthesis rate was at peak twice during seedling stage, which was once more than in any other stage of the growth of Perilla frutescens. Strong positive correlation was observed between stomatal conductance and transpiration rate. Conclusion: For maximum yield of leaf, stem, or seed, harvesting should take place either before flowers bloom or after leaves fall. All growth-spurring measures should be implemented before growth rate reaches a zenith or risk not being effective.