【摘要】 对6个不结球白菜品种的光合作用特性进行了研究。结果表明,在800μmol·m-2·s-1的光强下,不结球白菜的净光合速率以‘正大抗热青3号’最高,达16.37μmol CO2·m-2·s-1,其光合作用表观量子效率、羧化效率和水分利用效率也最高,分别为0.0442、0.0854mol·m-2·s-1和6.20μmol CO2·mmol-1H2O;暗呼吸速率以‘绿星’最低,为2.24μmol CO2·m-2·s-1;Pn-PFD响应曲线显示,在光强300μmol·m-2·s-1以下,各品种的净光合速率差异较小,在光强为300~1000μmol·m-2·s-1区段时,净光合速率随着光照强度增加而迅速增加。‘正大抗热青3号’光饱和点最高,达1910.3μmol·m-2·s-1,其光饱和点的净光合速率也最高,达20.2μmol CO2·m-2·s-1;不结球白菜不同品种净光合速率日变化进程相似,不论数值高低均呈双峰曲线型,有明显的“午休”现象。更多还原

【Abstract】 The photosynthetic characteristics of six Brassica campestris ssp.chinensis varieties were studied and the results indicated that at the light intensity of 800 μmol·m -2 ·s -1 ,‘Zhengda kangre qing No.3’ had the highest net photosynthetic rate,which amounted to 16.37 μmol CO₂·m -2 ·s -1 ,and its apparent quantum yield,carboxylation efficiency and water use efficiency were the highest amounting to 0.044 2, 0.085 4 mol·m -2 ·s -1 and 6.20 μmol CO₂·mmol -1 H₂O;‘Lüxing’ had the lowest dark respiration rate,which amounted to 2.24 μmol CO₂·m -2 ·s -1 .Pn-PFD curves indicated that where the light intensity was below 300 μmol·m -2 ·s -1 ,the varieties slightly differed in net photosynthetic rate and where the light intensity changed from 300 μmol·m -2 ·s -1 to 1 000 μmol·m -2 ·s -1 they quickly increased their net photosynthetic rates.‘Zhengda kangre qing No.3’ had the highest light saturation point amounting to 1 910.3 μmol·m -2 ·s -1 and its net photosynthetic rate was the highest reaching 20.2 μmol CO₂·m -2 ·s -1 at the light saturation point;The varieties showed similar daily net photosynthetic rate patterns which,no matter the photosynthetic rate was high or low,were a double peak curve that indicated remarkable midday depression.更多还原