以625 nm LED频闪光源，设定闪光频率为0．04 Hz或0．4 Hz、强弱照光时程比为50∶50构成强弱频闪光照射方式，采用光合测试系统（CIRAS‐2）测定了强弱频闪光下番茄叶片的碳吸收速率 Pn动态响应。结果表明：0．04 Hz频闪光下 Pn呈现峰―谷振荡，且随着弱光时程内 PA R的增加，Pn振荡幅度降低；而0．4 Hz下Pn无振荡现象。随着弱光时程内 PA R的增加，各强弱频闪光下的平均光合速率 Pn′均呈现迅速增加至接近连续光 Pn′的趋势，0．04 Hz或0．4 Hz的强弱频闪光的光合光能转化效率 LCE′较连续光显著增加，分别为10．83％～27．82％或39．40％～66．62％。可见，强弱频闪光的闪光频率和强弱照光时程的脉冲光强影响着LCE′的变化，而且二者适宜组合的强弱频闪光照射下会显著提高番茄叶片光合光能转化效率。%With illumination of tomato leaf by different high‐low intensity pulsed light (fre‐quencies 0 .04 Hz and 0 .4 Hz) from LED (peak wavelength 625 nm) ,the dynamic processes of net photosynthetic rate ( Pn) were measured by using portable photosynthesis system (CIRAS‐2) .The results showed that Pn charactered with peak‐valley oscillation ,and oscilla‐tion amplitudes of Pn decreased as the increasing of PA R within low intensity time under 0 .04 Hz .However ,Pn didn’t character with oscillation under 0 .4 Hz .The average values of net photosynthetic rate ( Pn′) under high‐low intensity pulsed light rapidly increased as the in‐creasing of PA R within low intensity time ,and approached the values under continuous light . T he light conversion efficiency (LCE′) each at 0 .04 Hz and 0 .4 Hz significantly increased than that under continuous light .Consequently ,the pulsed light frequency and PA R of pulsed light impacted on LCE′,and the optimum combination can significantly improved LCE′in tomato leaf .
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