The Study Of Photosynthetic Characteristics And Variety Of Symplocos Paniculata

Symplocos paniculata is a kind of deciduous shrub or arbors,a species of genus Symplocos from Symplocaceae family.It has white flowers,pleasant fragrance and blue fruits.It is a new flower resource with fruit,fragrance and a nice appearance.As the objectives of this study,the behaviors of Symplocos paniculata have been systematically studied in order to provide theoretical basis for the cultivation of Symplocos paniculata,including daily changes in photosynthetic characteristics,light response curves,CO₂ response of photosynthesis,chlorophyll fluorescence and its diversity in different environment.The results are as follows:1. The daily changes of photosynthetic characteristics of Symplocos paniculata are present by a two-peak curve in this paper.It has the first peak at 10:00 am and the second peak at 14:00 pm.This is an obvious indication of“lunch break”of photosynthetic characteristics.2.According to the light response curves,the three strains of Symplocos paniculata have high values of LCP and LSP.The values of LCP are 1300、1250、1125μmol·m-²·s^-1 and the values of LCP are 101.31、127.69、152.25μmol·m-²·s^-1.Symplocos paniculata also has lower net photosynthetic rate and maximal net photosynthetic rate.Therefore it can be concluded that Symplocos paniculata is heliophyte.3.According to the CO₂ response of photosynthesis,the three strains of Symplocos paniculata have high values of CSP and CCP.The values of CSP are 1250,1150,480μmo1·mo1^-1and the values of CCP are 135.23,157.30,127.54μmo1·mo1^-1,indicating that Symplocos paniculata is a typical C₃ plants.4.By comprehensive comparison between the four new models,such as rectangle hyperbola model,non-rectangle hyperbola model,exponential model and modificational rectangle hyperbola model,Symplocos paniculata is suitable for modificational rectangle hyperbola model and exponential model can be the second choice.5.The trend of the daily changes of chlorophyll fluorescence of Symplocos paniculata brings into correspondence.There is an apparent photoinhibition at 12:00pm.Symplocos paniculata has an excellent capability of using strong light.6.The net photosynthetic rate of Symplocos paniculata under the sun is higher than that in the shade.The photosynthetic characteristics of Symplocos paniculata is also similar.7.It is found that the net photosynthetic rate of the plants with bigger lenticels is clearly higher than those with smaller lenticels.For example,the average of Pn value of the plants with bigger lenticels is 3.27μmo1·m^-2·s^-1,whereas the average of Pn value of the plants with smaller lenticels is 2.30μmo1·m^-2·s^-1,namely,the Pn value of the plants with bigger lenticels is 1.4 times greater than those with smaller lenticels on average.8.There is a large variation in the photosynthetic characteristics of different plants.For example,the Pn value of Symplocos paniculata under the sun changed from 0.50 to 3.80μmo1·m^-2·s^-1.There was a difference of 7.6 times.Meanwhile,the Pn value in the shade was between 0.10μmo1·m^-2·s^-1 and 0.88μmo1·m^-2·s^-1（difference of 8.8 times）.