Effects of Different Light Intensities on Chlorophyll Fluorescence and Photosynthetic Physiology of Four Basil Plants
YANG Wen
ZHANG Jing
HE Weikai
ZHOU Xu
Abstract：By using four types of basil plants,including large leaved basil,purple basil,clove basil,and lemon basil,the effects of different light intensities on leaf chlorophyll content,photosynthetic characteristics,chlorophyll fluorescence parameters,and antioxidant systems were studied by setting 100%full light(L100),85%light(L85),70%light(L70),55%light(L55),and 40%light(L40).The results showed that with the decrease of light intensity,the plant height and biomass of the four basil plants showed a trend of first increasing and then decreasing,reaching their maximum under L85 treatment;The content of chlorophyll a+b showed:large leaf basil>lemon basil>clove basil>purple basil,while chlorophyll a/b showed the opposite trend.As the light intensity decreased,the initial fluorescence(Fo)and maximum fluorescence(Fm)of the four basils showed an increasing trend,while the maximum photochemical efficiency(Fv/Fm)and potential activity(Fv/Fo)of PS Ⅱ showed an increasing trend followed by a decreasing trend.The maximum net photosynthetic rate(Pm)of the four types of basil also showed a trend of first increasing and then decreasing,with larger increases in large leaf basil and lemon basil,both reaching their maximum values at L85,with an increase of 31.3%and 54.3%compared to L100.The apparent quantum efficiency(AQY)of four types of basil varied from 0.027 to 0.085 μmol/(m2·s).The light compensation point(LCP)of large leaf basil and lemon basil was maximum at L100,while purple basil and clove basil were maximum at L85.The light saturation point(LSP)of all four types of basil was maximum at L85 and minimum at L40.Compared to L100,the LSP of the four types of basil increased by 41.9%,12.8%,26.1%,and 7.0%at L85,respectively.Four types of basil plants could enhance the activity of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)in the antioxidant system,as well as the content of antioxidants such as total phenols,flavonoids,and vitamin C to adapt to the light environment.However,full light and extreme weak light environments could inhibit the growth and development of the four types of basil plants.In this experiment,85%light was more favorable for the growth of basil plants.
Keywords：OcimumIlluminationChlorophyllPhotosynthesisAntioxidant enzymesChlorophyll fluorescence
Publication Date：2025-05-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：11( 113-123 )