【摘要】 在岩溶石质山区,研究了不同生境下青檀的光合和荧光生理特性。结果表明:不同生境下,山顶青檀叶片的光饱和点(336μmol.m-2.s-1)、光补偿点(10.93μmol.m-2.s-1)较山脚高;在同一光照强度下,山顶青檀有着较高的净光合速率、蒸腾速率,而水分利用效率和叶水势却低于山脚;山顶青檀的荧光参数Fm、Fv、Fv/Fo、Fv/Fm、Fv’/Fm’均低于山脚。在低光下,山脚青檀的光化学淬灭系数(qP)和PSⅡ电子传递量子产率(ΦPSⅡ)较大;在强光下,山顶青檀的qP较大,而山脚和山顶青檀的ΦPSⅡ几乎没有差别;山顶青檀保持相对较低的暗呼吸速率。更多还原

【Abstract】 Pteroceltis tatarinowii is considered as an endangered species on the brink of extinction endemic to China.In order to reveal ecophysiology characteristics and gecological adaptability of Pteroceltis tatarinowii in different habitats,the photosynthetic characteristics and chlorophyll fluorescence parameter were studied.The results showed that the light saturation point(336 μmol·m-2·s-1),light compensate point(10.93 μmol·m-2·s-1),maximum net photosynthetic rate(Pnmax),and transpiration rate(Tr) of Pteroceltis tatarinowii were higher at the top site than that at foot site,both water utility efficiency(WUE) and water potential were lower at the top site.The fluorescence parameters Fm、Fv、Fv/Fo、Fv/Fm、Fv’/Fm’ at the top site were lower,but photochemistry quench(qP)and PSⅡ electronic transport quantum yield(ΦPSⅡ) of Pteroceltis tatarinowii were higher at foot site under shade condition;under strong light at the top site the qP were lower,ΦPSⅡ were similar as at foot site;and respiration rate of Pteroceltis tatarinowii was lower at the top site.It was obvious that some physiological properties varied with habitat change,Pteroceltis tatarinowii did not seem to be menaced with the strong light and heat drought stress.Consequently,Pteroceltis tatarinowii at the top site adapted the karst condition well by comprehensive ways such as increasing producing more photosynthetic substance and lowering the respiration et al,while had low shade-tolerance at the foot site.更多还原