关键词: 石漠化地区, 乡土草种, 干旱胁迫, 光合生理特性

Abstract: [Objective] The objective of this study was to select the local weeds that were more drought-resistant for ecological recovery in the karst rocky desertification area by studying the photosynthetic and physiological traits of native grasses under drought stresses. [Method] In this study,3common weeds (Eragrostis pilosa,Panicum bisulcatum and Arthraxon hispidus) in the karst rocky desertification area were selected as experimental materials.A pot experiment was conducted to simulate drought environment.The photosynthetic and physiological indexes,such as chlorophyll content,net photosynthetic rate (P_n),transpiration rate (T_r),water use efficiency (WUE),stomatal conductance (G_s) and intercellular CO₂concentration (C_i)were measured. [Results] ① the chlorophyll content of the 3 weeds was reduced by drought stress;② under the severe drought stress,the order of chlorophyll content was A. hispidus > P. bisulcatum > E.pilosa;③ the order of photosynthetic rate of 3 weeds was P. bisulcatum > E.pilosa > A. hispidus under the severe drought stress.The T_r of P. bisulcatum was the lowest but WUE was the high-est.Therefore,the drought-resistance of P. bisulcatum was the most excellent. [Conclusion] According to the photosynthetic performances,P. bisulcatumis more adaptable to drought stress in the rocky desertification area.

Key words: rocky desertification area, native grasses, drought stress, physiological indexes