青海省药用植物野薄荷光合特性的研究

Photosynthetic Characteristics of Mentha haplocalyx Briq. of the Medical Plant Growing in Qinghai,China

为了揭示青藏高原药用植物野薄荷的光合生理特性,本文采用常规光合指标测定方法对生长于青海民和、西宁和湟源3个不同海拔地区的药用植物野薄荷叶片的光合特性进行比较研究。结果显示:(1)叶片厚度产地湟源>民和>西宁,且西宁与民和、湟源间差异显著(p<0.01);(2)随着产地海拔升高,叶绿素和类胡萝卜素含量呈现上升趋势,而叶绿素a/b和叶黄素/叶绿素(A 505/A 652)含量则呈下降趋势,并且除类胡萝卜素含量在民和与西宁间有差异(p<0.05)外,其余差异均不显著(p>0.05);(3)净光合速率Pn和表观量子效率AQY均与海拔高度呈正相关,而光补偿点Ic和暗呼吸速率Rd则随着海拔升高呈下降趋势。同时,不同地区野薄荷表观量子效率间差异不显著(p>0.05),暗呼吸速率和净光合速率在民和、湟源间差异显著(p<0.05),而光补偿点则在民和、西宁和湟源3个地区相互间存在差异(p<0.05)。研究表明,野薄荷在光合特性上的变化是对低温、低气压、强太阳辐射等逆境的一种适应。

In order to reveal the photosynthetic characteristics of leaves of Mentha haplocalyx Briq. with officinal herbs growing at the Qing-Tibet Plateau,those at three different altitudes in Huangyuan,Xining and Minhe of Qinghai Province were comparatively studied by adopting conventional determination method of photosynthesis indices. The result showed that. （1）the thickness of leaves was the thickest in Huangyuan district and the thinnest in Xining district. And there were significant differences between Xining and Minhe,Huangyuan district （p〈0. 01）. （2）with altitude increasing,the carotenoid and chlorophyll content tended to rise,while the chlorophyll a/b and lutein/chlorophyll content tended to decline. And there were no significant differences among them （p〉0. 05） except for the carotenoid content there were significant differences between Minhe and Xining （p〈0.05）. （3）it was positive correlation between the photosynthetic rate and apparent quantum yield and elevation height, while the light compensation point and dark respiration rate decreased with increasing of the elevation. Simultaneity, there were no significant differences about the apparent quantum yield among three districts （p〉0.05） and there were significant the obvious differences on the dark respiration rate and photosynthetic rate between Minhe and Huangyuan （p〈0. 05）, but there were significant differences about the light compensation point among three districts （p〈0.05）. The study revealed that the changes of Mentha haplocalyx Briq. in its photosynthetic characteristics was an adaptive response to adverse environments including low temperature ,low air pressure,strong solar radialization,etc.