以芍药品种大富贵、黄金轮和杨妃出浴为试材，利用LI-6400便携式光合仪测定其光合日变化、光强和CO₂浓度的响应曲线。结果表明，3个品种净光合速率(Pn)日变化均呈“双峰”曲线，最高值出现在8:00时，存在光合“午休”现象；光强与CO₂响应曲线表明，黄金轮较另外两个品种的光合能力更强，而杨妃出浴有更好的弱光响应。CO₂浓度对Pn值的效应高于光强，光合有效辐射(PAR)，Pn值的增加主要受CO₂供应的限制，CO₂加富可提高芍药叶片的净光合速率。

The LI-6400 Portable Photosynthesis System is used to determine diurnal photosynthetic changes， light-response curves and CO₂-response curves of different species in three Paeonia lactiflora varieties， The result indicates that diurnal changes of net photosynthetic rates(Pn) in leaves of the three cultivars presented a typical bimodal curve and had ‘midday depression’ phenomenon； According to the light and CO₂ response curve can be obtained Huangjinlun than the other two species of photosynthetic ability is stronger， Yangfei bathing has a better response. CO₂ concentration on the effect of Pn value is higher than that of PAR， increase Pn value is mainly affected by CO₂ supply constraints， therefore， CO₂ enrichment can improve the net photosynthetic rate of Paeonia lactiflora

S682.1

甘肃省农业科学院科技创新项目(2012GAAS11-2)；甘肃省科技重大专项(1203NKDK019)部分内容