Studies On Photosynthetic Characteristics And Correlation Character Of Fresh Jujuba

Jujube,Zizyphus jujuba Mill belong to Generus Zizyphus jujuba Mill of Rhamnaceae.Fresh jujube,which is thin pericarp,has abundant syrup and particular flavor.It has been hotspot in the development of fruit tree in rencent years. In this study, Zizyphus Jujuba Var.inermis Lubei-Dongzao, Zizyphus Jujuba Var.inermis Beijing-Jidanzao and Zizyphus Jujuba Var.inermis Xianyou-3 are selected as test material,which carried out during May to October in2009. Their photosynthesis,leaf anatomical characteristics and chlorophyll fluorescence by shading conditions are studied,more than leaf weight, chlorophyll and sugar content, etc. parameters.The results are as follows:1. Daily variation of Pn of three varieties of fresh jujube presents "double peak" curve in May,July and September, with the obvious "midday depression" phenomenon; The midday depression of Pn in May are maily due to the stomatal limitation, July and September caused by the non-constraints.2. LCP of three varieties of fresh jujube are within 5.8-49.1μmol·m-2·s-1,and LSP are within 1414.3-1728.6μmol·m-2·s-1.They are heliophyte.CCP are 28.2-55.6μmol·m-2·s-1 and CSP are 955.0-1352.5μmol·m-2·s-1.CE and Pm:Beijing-Jidanzao>Xianyou-3> Lubei-Dongzao.3. There are positively correlations between SLW and daily average value of Pn in three varieties of fresh jujube.Chlorophyll a,b and total chlorophyll content are not mainly reasons that cause difference in Pn of them. The contents of reducing sugar,soluble sugar and starch of Lubei-Dongzao and Beijing-Jidanzao are higher than Xianyou-3, which has a certain correlation with Pm.4. The stomatal density of Lubei-Dongzao was significantly higher than Beijing-Jidanzao and Xianyou-3,while its differences of the stomatal length and width was not significant;There are statistically significant differences of palisade tissue,spongy tissue and leaf thickness,indicating leaf anatomy having a certain extent influence on photosynthesis .5. The light intensity and photosynthetic rate in Cloudy weather is lower than sunny.6. The value of Fv/Fm of Beijing-Jidanzao is higher than Lubei-Dongzao and Xianyou-3, with higher photosynthetic electron transport. The value ofΦPSⅡare lowest at 11:00, which high light intensity led to the rise in ETR and NPQ, but significant decline inΦPSⅡand qP.7. On different shading,the trend of Fv/Fm,Fv/Fo andΦPSⅡof Lubei jujube leaf is consistent.Chlorophyll a,b and total content and total sugar and starch content are significantly higher than the control,but chlorophyll a/b value is lower. 50% shading has the strongest using of low light.Moderate shading can accumulate more organism, and promote growth..