Effect of fertilization treatment on the photosynthetic light-response characteristics of Salvia miltiorrhiza Bunge

【Objective】 The research studied the relationship between the photosynthetic light-response curves and fertilizing treatments of Salvia miltiorrhiza to provide a basis for optimal fertilization in field cultivation.【Method】 The photosynthetic light-response curves of S.miltiorrhiza under four fertilizing treatments,CK,MX,N10 and N20,were measured using a Li-6400 portable photosynthesis system.A modified nonrectangular hyperbola was adopted to fit the light-response curves.【Result】 Compared with CK treatment,the net photosynthetic rate(Pn) and the maximum net photosynthetic rate(Amax) was increased significantly under N10,N20 and MX treatment;the values of transpiration rate(Tr),intercellular CO2 concentration(Ci),and stomatal conductance(Gs) were increased significantly under N20 treatment.The values of light saturation point(LSP) and light compensation point(LCP) were decreased in N10 treatment,increased in N20 treatment;but in MX treatment,the former was increased,the later decreased.【Conclusion】 These results indicated that the nitrogen fertilization can increase the net photosynthetic rate and the photosynthetic ability of S.miltiorrhiza was enhanced under mixture fertilization treatment.