中文摘要：

对青海省民和、西宁和湟源3个地区的药用植物薄荷（Mentha haplocalyx Briq.）的净光合速率和叶绿素荧光参数的变化进行分析比较。结果显示：（1）最大净光合速率（Pn）湟源〉西宁〉民和;（2）PSⅡ反应中心最大光化学效率（Fv/Fm）以及PSⅡ反应中心活性参数（1/Fo-1/Fm）和实际光化学量子效率（ΦPSⅡ）的变化趋势相同,均以西宁最高,而相应的光合功能的相对限制（LPDF）西宁最低;（3）西宁薄荷的光化学猝灭系数（qP）最高（0.875）,而非光化学猝灭（NPQ）则最低（1.114）。研究表明,青海薄荷有光抑制现象发生,但并没有造成PSⅡ反应中心的不可逆破坏;西宁薄荷光化学能力较高而湟源薄荷对于过剩光能的耗散能力较高。

英文摘要：

The officinal herb species of Mentha haplocalyx Briq.were used as a researchful material to study the characteristics of net photosynthetic rate and chlorophyll fluorescence parameters,which collected from Minhe,Xining and Huangyuan in Qinghai Province.The result showed that（1） net photosynthetic rate（Pn）in Huangyuan was the highest in three samples;（2） the PSⅡ maximum photochemical efficiency（Fv/Fm）,actual quantum efficiency（ΦPSⅡ） and active of PSⅡ reaction center（1/Fo-1/Fm） were the highest in Xining sample,corresponding the relative limitation of photosynthetic function（LPDF） was lowest in Xining sample;（3） The photochemical fluorescence quenching（qP） was highest in Xining sample among the three samples（0.875）,but non-photochemical fluorescence quenching（NPQ） was highest in Huangyuan sample（1.114）.Those results indicated that this herb can occur photoinhibition in strong light intensities,but these did not cause irreversible damage in PSⅡ reaction centers.Xining sample had the highest ability to utilize exciting energy and Huangyuan sample could dissipate excessive exciting energy thermally in three samples.