Effects of drought stress on features of chlorophyll fluorescence of Eremochloa ophiuroides

The chlorophyll fluorescence parameters and chlorophyll content of 2 strains(Yaan and Common)of centipedegrass from different origins were studied under 3 irrigation regimes(percentage of field water capacity):full irrigated(80%),moderate drought(50%),heavy drought(35%).The results indicated that carotinoids content of 2 strains and as the chlorophyll a+b content of Common were significantly increased by heavy drought,but the change of chlorophyll a+b content of Yaan was not significant.For both 2 strains,it was observed that maximum fluorescence intensity(Fm),variable fluorescence(Fv),maximum quantum yield of PSII photochemistry(Fv/Fm),PSII potential activity(Fv/Fo)and effective quantum yield of PSII photochemistry(Yield)were significantly decreased by drought while minimum fluorescence intensity(Fo),photochemical quenching(qP)and Non-photochemical quenching(qN)were not significantly affected.Compared with control,Fv/Fm in Common and Yaan were decreased by 15% and 5%,respectively.Based on these observations,it could be concluded that PSII of centipedegrass were harmed by drought.However,different responses were also observed between two strains.Under heavy drought stress,the increased Fo and decreased Fm were observed in Common.However,Fm was not significantly affected in Yaan strain,and n contrast,Fo was decreased.