Nixon E H, Markhart A H, Koukkari W L
Prog Clin Biol Res. 1987;227A:67-79.
Temporal fluctuations of stomatal aperture are important to water use efficiency. Techniques that use point measurements widely spaced in time such as diffusive resistance porometry (DRP) or pot weighing (PW) may not provide a complete description of changes in stomatal aperture. Three techniques, DRP, PW, and continuous flow porometry (CFP), were used to examine stomatal aperture changes in Hordeum vulgare L. and Abutilon theophrasti Medic. Plants maintained in controlled environment chambers at 23 degrees C under LD 12:12 were monitored during 2 days of continuous illumination (LL) and a subsequent LD cycle. Oscillations with periods of about 24 hr were observed in both leaf surfaces in the two species. In addition, during LL, high-frequency fluctuations were sometimes superimposed on the 24-hr oscillation. There was better agreement between the results of CFP and DRP in Abutilon than in Hordeum. The reason for this difference is unclear. CFP revealed rapid fluctuations in stomatal aperture that were not observed with the other techniques.
气孔孔径的时间波动对水分利用效率很重要。使用在时间上间隔较大的点测量技术，如扩散阻力气孔计（DRP）或盆栽称重（PW），可能无法完整描述气孔孔径的变化。采用了三种技术，即DRP、PW和连续流气孔计（CFP），来检测大麦和苘麻的气孔孔径变化。在12小时光照/12小时黑暗（LD 12:12）、23摄氏度的可控环境箱中培养的植物，在连续光照（LL）的2天以及随后的LD循环期间进行监测。在这两个物种的叶片表面均观察到了周期约为24小时的振荡。此外，在LL期间，高频波动有时叠加在24小时振荡之上。苘麻中CFP和DRP的结果之间的一致性比大麦中的更好。这种差异的原因尚不清楚。CFP揭示了气孔孔径的快速波动，而其他技术未观察到这种波动。
