毛叶枣光合特性研究

Studies on Photosynthetic Characteristics of Ziziyphus mauritiana Lam.

用Li-6400光合作用仪对田间条件下2年生毛叶枣光合特性进行了研究。结果表明:(1)毛叶枣外围叶片晴天的净光合速率(Pn)日变化为双峰和一降不起的单峰曲线,内膛叶片Pn日变化不规则。(2)按净光合速率的日均值和日最大值分析,观测期内季节变化呈下降趋势。(3)不同月份内外叶片Pn对光和CO2响应有差别。光补偿点11.12～49.05μmol/m2·s,光饱和点1808～2000μmol/m2·s,表观量子效率0.04351～0.06538;叶片CO2补偿点为56.10～67.24μmol/m2·s,饱和点为663～763μmol/m2·s,羧化效率0.04128～0.09094,毛叶枣具有明显C3植物特征。⑷毛叶枣光合适温为18～34℃。

Under field conditions,the photosynthetic characteristics of2-year-old Ziziyphus mauritiana Lam.were studied by using the Li-6400portable photosynthesis system.The results were as follows:(1)In sunny days,The diurnal variation of net photosynthetic rate(Pn)of peripheral leaves presented bimodal and a once-down-never-up single peak curve,the diur-nal variation of Pn of inner leaves was irregular.(2)During observation,the seasonal variation of average and maximum Pn take on down trend.(3)Among different months,there were differences in the responses of leaf Pn to light intensity and CO 2 concentration.The light compensate(Lcp)and saturated(lsp)point of leaves were11.12～49.05μmol/m 2 ·s and1808～2000μmol/m 2 ·s,respectively;the apparent quantum efficiency was between0.04351and0.06538;the CO 2 compensate(Ccp)and saturated(Csp)point were56.10～67.24μmol/mol and663～763μmol/mol,respectively;the carboxying efficiency was between0.04128and0.09094,which indicated that Ziziyphus mauritiana take on obvious character of C 3 type plant.(4)The proper temperature of photosynthesis were18～34℃.