应用田间根系分区供水方法,研究根系分区交替水分胁迫(APRD)、固定单侧水分胁迫(FPRD)与对照两侧同时供水(BPRI)对2年生草乌光合特性的影响.结果表明:1)各水分条件下,叶片蒸腾速率(n)随着周期的进行逐渐减小,后期随着处理水分亏缺的加重,峰值减小,峰出现时间前移；2)APRD处理下,草乌通过维持相对较低的气孔导度(G6),在Tr降低30％的前提下,Pn比对照BPRI与FPRD处理分别提高4.16％,37.43％,反映出APRD处理对气孔的优化调节；3)各水分条件下,草乌的水分利用效率(WUE)日变化均呈双峰曲线,APRD处理可显著提高草乌的WUE,分别比对照BPRI和FPRD处理提高20.39％和10.53％,对草乌在干旱地区栽培意义重大；4)各水分条件下草乌的光合一光响应曲线变化趋势基本一致,表观量子效率( AQY)差异不显著,光饱和点(LSP)和光补偿点(LCP)协同变化表明APRD处理在一定程度上增强了草乌对光环境的适应能力；最大净光合速率(Pmax)表现为APRD处理下最高,FPRD处理略低于对照BPRI; APRD处理下,草乌叶片暗呼吸速率(Rd)最低,有利于干物质积累.根系分区交替水分胁迫通过供水调控挖掘了草乌本身的生物学节水潜力.%A field experiment was conducted with Aconitum kusnezoffii to investigate effects of alternate partial root zone drying ( APRD ), fixed partial root zone drying ( FPRD ), and whole root zone irrigation ( BPRI) on photosynthesis characteristics of two-year-old A. kusnezoffii, aimed at providing a theoretical basis for cultivating this kind of plant for the arid area. The results showed that, 1 ) The transpiration rate ( Tr) in all three treatments were decreased gradually with experimental time. The peak value decreased and the peak point moved forward with the aggravated water stress. 2) A. kusnezoffii in APRD treatment had lower atomatal conductance than the other treatments, and the net photosynthetic rate ( Pm) was higher than BPRI and FPRD by 4. 16% and 37.43% respectively when the Tr in APRD treatment was decreased than BPRI by 30% , reflecting that the APRD treatment could optimally adjust the stomatal behavior. 3 ) The diurnal change of water use efficiency in three treatments was all double peak curves. The WUE in the APRD treatment was significantly higher than that in BPRI and FPRD by 20. 39% and 10. 53% , respectively. (4)The photosynthetic light response curve in the three treatments was generally similar. The apparent quantum yield(AQY) of photosynthesis in three treatments was similar to each other. The collaborative variation of light saturation point ( LSP) and light compensation point ( LCP) showed that the ability to adapt to light in the treatment of APRD was enhanced to some extent. The maximum net photosynthesis rate (Pmax) in the APRD treatment was the highest. The dark respiration rate ( Rd ) in the APRD treatment was lowest, suggesting that A. kusnezoffii reduced its consumption so as to adapt arid environment. Alternate partial root zone drying ( APRD) developed the biological water-saving potential plants by regulating water supply.
展开▼
