光周期对促成栽培芍药生长开花和叶绿素荧光动力学影响

Effects of photoperiod on the growth,flowering and chlorophyll fluorescence kinetics of forced Paeonia lactiflora

为探讨光周期对促成栽培芍药生长开花和光合机制的影响,给予冬季促成栽培芍药‘大富贵’(DFG)和‘桃花飞雪’(THFX)14 h/d和18 h/d光周期处理,以自然光周期9 h/d为对照(CK)。结果表明:与CK相比,14 h/d光周期对芍药2个品种的生长、叶绿素积累和开花均有利,并促进PSⅡ最大量子效率(Fv/Fm)上升和增强PSⅡ向下游供应电子的能力,使PSⅡ-PSⅠ-碳同化快速达到动态平衡;与CK相比,18 h/d光周期不利于芍药DFG茎伸长,并对其开花有显著抑制作用;18 h/d光周期处理,芍药2个品种电子传递链均在PSⅠ处受阻,同时PSⅠ-碳同化间电子传递平衡被打破;芍药不同品种光合电子传递对光周期响应有差异,DFG整体电子传递活性比THFX高,在14h/d光周期下,PSⅡ-PSⅠ-碳同化动态变化可更快达到新的动态平衡并保持稳定,对光周期的适应性也比THFX强,这与其生长开花情况表现一致。

The objective of this study was to investigate the effects of photoperiods on the growth,flowering and photosynthetic mechanisms of forced Paeonia lactiflora. Two forced P. lactiflora cultivars ‘Da Fu Gui＇（ DFG） and ‘Tao Hua Fei Xue＇（ THFX） were treated with 3 different photoperiods： 14 h /d,18 h /d and 9 h / d as control（ CK）. The results showed that： Compared with CK,14 h / d photoperiod promoted the growth,chlorophyll accumulation and flowering of both cultivars,gradually increased maximum quantum efficiency of PSⅡ（ Fv/ Fm） and electron supply of PSⅡ to PSⅠ,and a new equilibrium of electron transport between PSⅡ-PSⅠ-carbon assimilation could be quickly reached. In comparison with CK,18 h / d photoperiod was disadvantageous for the shoot elongation and significantly inhibited the flowering of DFG. In addition,18 h / d photoperiod negatively affected electron transport chain at PSI,and broke the balance between PSI-carbon assimilation for both cultivars. The photosynthetic electron transport chain of two P. lactiflora cultivars responded differently to photoperiods. DFG had higher electron transport activity than THFX,and under 14 h / d photoperiod,dynamic changes of PS Ⅱ-PSI-carbon assimilation of DFG could reach a new dynamic equilibrium faster than THFX and keep the balance,therefore,DFG had a stronger photoperiod adaptability than THFX.