Photosynthetic characteristics of Primula denticulata and Primula pseudodenticulata.

The LI-6400 portable photosynthetic system was employed to measure the photosynthetic characteristics of Primula denticulata and Primula pseudodenticulata,which transplanted in Kunming,in order to study and compare their photosynthetic characteristics.The results were as follows:(1)the diurnal changes of photosynthetic rate(Pn) and transpiration rate(Tr) of P.denticulata showed "dome" pattern.The peak values of Pn and Tr appeared at 13:00 and 16:00,respectively.P.pseudodenticulata had lower Pn and Tr and remained constant within a certain range.The diurnal changes of Pn and Tr showed significant difference between P.denticulata and P.pseudodenticulata;(2)Leaf mass per unit area(LMA) and leaf nitrogen content(LNCa) had no effect on related photosynthetic parameters.However,nitrogen content partitioning in Rubisco(PR) and biological energy(PB) had significant influences on photosynthetic parameters such as LCP,Vcmax,Jmax and CE;(3)When compared with the P.pseudodenticulata,P.denticulata had wider adaptation to high light intensity,temperature and low relative humidity,it showed stronger adaptation to environment and showed higher photosynthetic capacity.