| 摘要: |
| 【目的】揭示灌水量对春玉米大喇叭口期光合日变化规律，进一步明确玉米干物质积累的差异性。【方法】以春玉米品种广德5为试验材料，在2018年灌水量定位试验基础上，2019年设置了DGT1（315 m3/hm2）、DGT2（645 m3/hm2）、DGT3（945 m3/hm2）、DGT4（1 275 m3/hm2）、DGT5（1 605 m3/hm2）5个灌水量以及在2020年增设不灌水雨养对照（DGT0），分析灌水量对春玉米大喇叭口期最大展开叶叶片光合特性日变化、光响应曲线以及干物质积累的影响。【结果】随着灌水量的增加，各处理光合速率（Pn）日变化、气孔导度（Gs）日变化以及蒸腾速率（Tr）日变化均呈双峰曲线变化趋势，存在午休现象，达到双峰时间相同，峰值大小存在一定差异；而各灌水量处理的胞间CO2摩尔分数（Ci）日变化则呈先降低后升高的“V”字形曲线变化趋势。不同灌水量处理的光响应曲线拟合较好，2020年和2019年的最大净光合速率均以DGT3处理最大，2019年DGT3处理分别比DGT1、DGT2、DGT4、DGT5处理模拟出的最大净光合速率高出8.71%、3.68%、13.75%、13.59%。2020年DGT3处理分别比DGT0、DGT1、DGT2、DGT4、DGT5处理模拟出的最大净光合速率高出25.6%、22.0%、8.2%、17.0%、22.2%。2019年单株干物质量变化DGT3处理比DGT1、DGT2、DGT4、DGT5处理分别高出14.1%、17.8%、28.9%、12.1%。2019、2020年在DGT3处理和DGT1处理均存在显著性差异（P<0.05）。【结论】综上可知，玉米较适宜滴灌量为945 m3/hm2。 |
| 关键词: 春玉米；灌水量；光合日变化；光响应曲线；干物质 |
| DOI：10.13522/j.cnki.ggps.2022596 |
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| 基金项目: |
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| Effect of Irrigation Amount on the Diurnal Changes of Photosynthesis and Dry Matter Accumulation of Maize in the Horn Mouth Stage |
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MENG Tiantian, DU Xiangyu, ZHANG Xiangqian, CHEN Lirong,
LU Zhanyuan, LAN Huiqing, LIU Yajie, WU Di
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1. Agricultural University of Hebei, Baoding 071000, China; 2. Mengcao Ecological Environment (Group) Co., Ltd.,
Hohhot 010070, China; 3. Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Hohhot 010031, China;
4. Key Laboratory of Ecological Restoration and Pollution Prevention of Degraded Farmland of
Inner Mongolia Autonomous Region, Hohhot 010031, China; 5. Inner Mongolia University, Hohhot 010020, China
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| Abstract: |
| 【Objective】To reveal the diurnal change rule of photosynthesis of spring maize under different irrigation amount at the big bell mouth stage, further clarify the difference of dry matter accumulation of maize. 【Method】Taking the spring maize variety Guangde 5 as the experimental material, the experiment began in 2018, and set five irrigation amount in 2019, namely DGT1 (315 m3/hm2), DGT2 (645 m3/hm2), DGT3 (945 m3/hm2), DGT4 (1 275 m3/hm2), DGT5 (1 605 m3/hm2), and added no irrigation rain fed control (DGT0) in 2020, The effects of irrigation amount on the diurnal changes of photosynthetic characteristics, light response curves and dry matter accumulation of the largest unfolding leaves of spring maize at the bell mouth stage were analyzed.【Result】The results showed that with the increase of irrigation amount, the diurnal changes of photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) in each treatment showed a bimodal curve trend, and there was a midday rest phenomenon. The time to reach the bimodal was the same, and the peak values were different; However, the diurnal variation of intercellular CO2 concentration (Ci) of each treatment showed a "V" shaped curve that decreased first and then increased. The light response curves of different irrigation amount were well fitted. The maximum net photosynthetic rate of DGT3 treatment was the largest in 2020 and 2019. The maximum net photosynthetic rate of DGT3 treatment in 2019 was 8.71%, 3.68%, 13.75% and 13.59% higher than that of DGT1, DGT2, DGT4 and DGT5 treatment respectively. In 2020, the maximum net photosynthetic rate of DGT3 treatment was 25.6%, 22.0%, 8.2%, 17.0% and 22.2% higher than that of DGT0, DGT1, DGT2, DGT4 and DGT5 treatment respectively. In 2019, the dry matter of single plant in DGT3 was 14.1%, 17.8%, 28.9% and 12.1% higher than that in DGT1, DGT2, DGT4 and DGT5 respectively. In 2019 and 2020, there were significant differences between DGT3 treatment and DGT1 treatment (P<0.05).【Conclusion】It was concluded that the appropriate irrigation amount spring maize was 945 m3/hm2. |
| Key words: spring maize; irrigation amount; diurnal variation in photosynthesis; light response curve; dry matter |
