花前不同时段夜间增温对冬小麦旗叶光合特性及产量的影响

全球变暖表现出夜间增温幅度大于白天的非对称性增温特点，小麦作为温凉型作物，产量和生理特性易受非对称性增温的影响。为探究花前夜间增温对冬小麦光合特性及产最形成的影响，以春性品种扬麦18和半冬性品种烟农19为试验材料，采用大田盆栽方式，利用被动式增温装置分别在分蘖期至拔节期(WT-J)、拔节期至孕穗期(WJ-B)、孕穗期至开花期(WB-A)三个时间段进行夜间增温处理，以不增温为对照(CK),分析经过三个花前不同时段夜间增温后小麦旗叶光合特性及产量特性的变化。结果表明，花前夜间增温使小麦旗叶灌浆期的净光合速率、蒸腾速率、气孔导度和胞间CO₂浓度均有所增加，WT-J、WJ-B处理均提高了冬小麦旗叶面积、最大光化学效率和实际光化学效率，同时使旗叶气孔密度和气孔指数较CK分别增加了12.64%、8.45%和10.21%、7.56%。扬麦18、烟农19的可孕小穗数在WT-J处理下较CK分别提高了9.01%和5.25%。扬麦18开花期干物质积累量在WT-J和WJ-B处理下较CK分别提高了13.18%和10.23%,烟农19在WT-J和WJ-B处理下较CK分别提高了16.21%和1...

Effect of Night Warming at Different Stages before Flowering on Photosynthetic Characteristics of Flag Leaves and Yield Formation of Winter Wheat

Global warming shows that the amplitude of temperature increase at night is greater than that during the day, and the yield and physiological characteristics of wheat, as a cool and warm crop, are easily affected by the asymmetric temperature increase. In order to explore the effect of night warming before anthesis on the photosynthetic characteristics and yield of winter wheat, a spring variety Yangmai 18 and a semi-winter variety Yannong 19 were used as experimental materials, and the pot cultivation method in wheat field was adopted. The passive warming device was used to conduct nighttime warming treatment at three time intervals, namely, tillering stage to jointing stage (WT-J), jointing stage to booting stage (WJ-B), booting stage to flowering stage (WB-A), with no warming as the control (CK), to explore the effects of three different pre-anthesis night warming treatments on the photosynthetic characteristics of flag leaves and yield components of wheat. The results showed that the net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO₂ concentration of wheat flag leaf at filling stage were all increased by night warming before anthesis. WT-J and WJ-B treatments increased the area of winter wheat flag leaf, the maximum photochemical efficiency and the actual photochemical efficiency. The stomatal density and stomatal index of flag leaf were increased by 12.64%, 8.45%, 10.21%, and 7.56%, respectively, compared with those of CK. The number of fertile spikelets of Yangmai 18 and Yannong 19 under WT-J treatment were increased by 9.01% and 5.25%, respectively, compared with that of CK. Under WT-J and WJ-B treatments,the dry matter accumulation of Yangmai 18 at flowering stage was 13.18% and 10.23% higher than that of CK, respectively, and that of Yannong 19 was 16.21% and 12.13% higher than that of CK, respectively. Under WT-J treatment, the dry matter accumulation of Yangmai 18 and Yannong 19 was increased by 8.67% and 9.01% on average compared with that of CK. Under WT-J and WJ-B treatments, the yield of Yangmai 18 was increased by 4.75% and 3.40%, and that of Yannong 19 was increased by 5.67% and 3.36%, respectively. In this experiment, night warming at different periods improved the photosynthetic capacity of flag leaves at the early filling stage, slowed down the senescence of flag leaves after anthesis, promoted the accumulation of dry matter after anthesis, and then achieved high yield.