江汉大学学报（自然科学版）

为探究花后弱光胁迫对糯小麦和非糯小麦旗叶叶绿素荧光特性及产量形成的影响。于2023-2025年在大田条件下，以糯小麦‘济糯2号’（JN2）和非糯小麦‘荃麦725’(QM725)为材料，设置4个遮光水平（不遮光、花后遮光10%、花后遮光20%和花后遮光30%），分析花后弱光胁迫对两个品种旗叶叶绿素荧光特性与产量形成的影响。结果表明，与对照相比，两个小麦旗叶SPAD值增加，但旗叶光化学猝灭系数（qP）、最大光化学效率（Fv/Fm）和实际光化学效率（ΦPSⅡ）呈现下降趋势。花后弱光胁迫降低了花后光合产物的积累量及其对籽粒的贡献率。与对照相比，花后弱光胁迫显著降低小麦籽粒平均灌浆速率和最大灌浆速率，进而导致千粒重和产量降低。可见，花后弱光胁迫降低小麦旗叶光化学猝灭系数，即PSⅡ电子传递效率下降，进而降低PSⅡ实际光化学效率，使小麦干物质积累尤其是花后干物质积累显著降低，降低小麦籽粒平均灌浆速率与最大灌浆速率，进而降低籽粒重和产量。遮光30%处理下，糯小麦‘济糯2号’产量较对照降低24.48%，降幅高于非糯小麦品种‘荃麦725’(20.1%)，表明相同弱光条件下弱光胁迫对糯小麦‘济糯2号’的影响更大。

To investigate the effects of post-anthesis weak-light stress on the chlorophyll fluorescence characteristics of flag leaves and yield formation in waxy and non-waxy wheat,field experiments were conducted from 2023 to 2025 using the waxy wheat cultivar 'Jinuo 2'(JN2)and the non-waxy wheat cultivar 'Quanmai 725'(QM725). Four shading treatments were set,including no shading,10% shading after anthesis,20% shading after anthesis,and 30% shading after anthesis,to analyze the effects of post-anthesis weak-light stress on flag leaf chlorophyll fluorescence characteristics and yield formation in the two cultivars.The results showed that,compared with the control,post-anthesis weak-light stress increased the SPAD values of flag leaves in both wheat cultivars,whereas the photochemical quenching coefficient(qP),maximum quantum efficiency of PSⅡ photochemistry(Fv/Fm),and actual photochemical efficiency of PSⅡ (ΦPSⅡ) showed decreasing trends. Postanthesis weak-light stress reduced the accumulation of photosynthetic assimilates after anthesis and their contribution rate to grain yield. Compared with the control,post-anthesis weak-light stress significantly decreased the average and maximum grain-filling rates,thereby reducing the 1000-grain weight and yield. These results indicated that postanthesis weak-light stress reduced the photochemical quenching coefficient of wheat flag leaves,indicating a decline in PSII electron transport efficiency,which in turn reduced the actual photochemical efficiency of PSII. Consequently,dry matter accumulation,especially post-anthesis dry matter accumulation,was significantly reduced,and the average and maximum grain-filling rates were decreased,ultimately leading to lower grain weight and yield. Under 30% shading treatment, the grain yield of waxy wheat cultivar 'Jinuo 2'decreased by 24. 48% compared with the control,which was greater than the decrease observed in the non-waxy wheat cultivar 'Quanmai 725'(20. 1%). This suggests that,under the same weak-light conditions,weak-light stress had a greater effect on the waxy wheat cultivar 'Jinuo 2'.