Study On Photosynthetic Characteristics Of Jujubes In Greenhouse

The experiment was carried out in six varieties of jujubes, LI-6400 portable photosynthesis system was used to analyze diurnal variations of leaves of huping jujube. Light response curves of photosynthesis were studied in leaves of huping jujube in the open field and six varieties of jujubes in greenhouse. The chlorophyll content and CCI were also investigated. The main results were as follows.(1) The diurnal variations of photosynthetic rate of huping jujube behaved as double-peak pattern. The first peak of photosynthetic rate appeared at 10 am which was higherer than the second peak at 15:00.(2) The diurnal variations of Tl and T of huping jujube beheaved as one-peak pattern, the peak appeared at 14:00; the diurnal variations of PAR beheaved as one-peak pattern, the peak was at 12:00; the diurnal variations of RH beheaved as "V" pattern, the lowest point was at 14:00; the daily changes of Gs and Tr presented as bimodal curve which was similar as Pn; the diurnal variations of Ci which was opposite to Pn was bimodal curve; the diurnal variations of WUE presented as bimodal curve. The Photosynthesis Characteristics of jujube was determined by the environmental and Physiologic factors, while the effect and extent of each factor were different. PAR, Tr, Gs, Ci,WUEwere important factors for Pn of huping jujube in greenhouse.(3) The LSP of huping jujube in greenhouse was lower than outside, the PAR (842.5 ?mol·m-2·s-1) could not meet the demand of the LSP (1480 ?mol·m-2·s-1) of huping jujube in greenhouse.(4) The range of LSP of six varities of jujubes was 1212.50?1637.5 ?mol·m-2·s-1. The order (from higher to lower) was:meimi jujube> duanzi jujube> huping jujube> zaocuiwang jujube> lengbaiyu jujube> dong jujube; the order (from higher to lower) of Pm was:zaocuiwang jujube> duanzi jujube> meimi jujube> huping jujube> lengbaiyu jujube> dong jujube; the range of LCP was 113.63-148.99 ?mol·m-2·s-1, the order (from higher to lower) was:zaocuiwang jujube> lengbaiyu jujube> duanzi jujube> dong jujube> huping jujube> meimi jujube; the order of AQY was:zaocuiwang jujube> duanzi jujube> lengbaiyu jujube> meimi jujube> dong jujube> huping jujube.(5) The content of Chla, Chlb, ChlT and CCI of huping jujube in greenhouse was higher than in the open field, but Chla/Chlb was lower. The high Chlb content was useful for huping jujube under the condition of weak light in greenhouse.(6) The order (from higher to lower) of CCI index was:dong jujube> huping jujube> meimi jujube> zaocuiwang jujube> duanzi jujube> lengbaiyu jujube; the order (from higher to lower) of Chla was:dong jujube> huping jujube>zaocuiwang jujube> meimi jujube> duanzi jujube>lengbaiyu jujube; the order (from higher to lower) of the Chlb was:dong jujube> zaocuiwang jujube> meimi jujube> duanzi jujube>huping jujube>lengbaiyu jujube; the order of ChlT was:dong jujube> zaocuiwang jujube> huping jujube> meimi jujube> duanzi jujube> lengbaiyu jujube; the order (from higher to lower) of Chla/Chlb was:huping jujube> lengbaiyu jujube> meimi jujube> dong jujube> zaocuiwang jujube> duanzi jujube. The chlorophyll content of dong jujube and zaocuiwang jujube was the highest, while Chla/Chlb was lower. It was fit for growing under the weak light. In the mature period,the LCP?LSP of dong jujube were low,it was fit for growing in the weak light.The LCP of meimi jujube was low while the LSP?Pm was high, it was fit for growing in the weak and intense light.(7) In the mature period of jujubes in greenhouse, correlation coefficients between Pn and chlorophyll content of six virieties of jujubes was not obvious. The degree of chlorophyll content could not show the photosynthesis characteristics of different virieties.