Abstract: Anthocyanins contents,gas exchange,chlorophyll a fluorescence kinetics and reflectance spectroscopy of leaves under different light intensity were investigated in purple basil leaves.The results indicated that the leaves became thick under the high light and became thin under the weak light.Compared with the purple basil grown under the weak light,the chlorophyll and anthocyanins content per leaf area were significant increased under the high light.In addition,the plant grown under the high light,the light compensation point(LCP) and light saturation point(LSP)were significantly raised;the apparent quantum yield(AQY),net photosynthetic rate(Pn),maximal photochemical efficiency(Fv/Fm) and photosystem II capability index(PI)sharply increased;the efficiency of open centers of photosystem II(Fv′/Fm′),photochemical quenching(qP)and actual photosystem II efficiency(ΦPSII) gradually enhanced,while non-photochemical quenching(NPQ) decreased;the photochemical reflectance index(PRI) of leaves were slightly down regulated.On these bases,we concluded that light intensity to regulate photosynthetic capacity by way of influencing leaves thickness,specific leaf area,pigment content,photosystem II activity;The enhanced of photosynthetic capacity and anthocyanins contents is beneficial to relieve strong light stress in purple basil leaves.

Key words: Purple basil, Gas exchange, Chlorophyll fluorescence, Anthocyanins, Xanthophyll cycle

CLC Number: 

• S6