| 引用本文: | 李伟康,吴明清,谭明东,等.元江干热河谷区微喷灌水钾调控对柑橘光合特性影响研究[J].灌溉排水学报,2026,45(7):70-82. |
| Li Weikang,Wu Mingqing,Tan Mingdong,et al.元江干热河谷区微喷灌水钾调控对柑橘光合特性影响研究[J].灌溉排水学报,2026,45(7):70-82. |
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| 摘要: |
| 【目的】探究微喷灌水钾管理对元江干热河谷地区柑橘果实膨大期和成熟期光合特性的调控效应，揭示不同生育阶段的水钾调控机制及生理路径。【方法】以12 a生“冰糖橙”柑橘为试材，在果实膨大期和成熟期开展水分和钾肥二因素混合试验：设置1个对照（CK），灌水量为充分灌水量，施钾量为当地常规施钾量；水分设置3个亏缺处理水平，即轻度亏缺（LD）、中度亏缺（MD）和重度亏缺（SD）处理，灌水量分别为CK的85%、70%和55%；钾肥设置2个处理水平，即中钾（MK）和低钾（LK）处理，施钾量分别为CK的85%和70%，测定复水前后光合指标的日变化特征，并采用结构方程模型（SEM）解析水钾对柑橘光合的生理调控路径。【结果】①果实膨大期和成熟期复水前后净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、羧化速率（CE）及瞬时水分利用效率（WUEi）日均值均随水分亏缺程度的降低而升高（p＜0.001），胞间CO2摩尔分数（Ci）则表现为降低（p＜0.001），LD处理为光合最优水分阈值。②钾肥调控光合作用存在生育阶段差异，表现为膨大期MK处理Pn显著提升（p＜0.001），而成熟期则显著抑制（p＜0.001）。③灌水量影响的气孔行为是果实膨大期和成熟期光合作用的关键限制因子；膨大期增施钾肥通过提高叶片含钾量协同增强气孔与非气孔过程，促进了光合作用；成熟期增施钾肥则因加剧非气孔限制，反而抑制光合。【结论】建议在膨大期采用“中钾+轻度亏水（MK+LD）”，成熟期采用“低钾+轻度亏水（LK+LD）”模式，实现节水节肥的同时提升柑橘光合性能。 |
| 关键词: 柑橘；微喷灌；水钾一体化；光合日变化 |
| DOI：10.13522/j.cnki.ggps.2026038 |
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| Effects of water-potassium regulation under micro-sprinkler irrigation on citrus photosynthesis during fruit development stages in the Yuanjiang dry-hot valley |
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Li Weikang, Wu Mingqing, Tan Mingdong, Cui Ningbo, Gao Zhiyong, Xing Liwen,
Wen Shenglin, Jiang Shouzheng, Wang Zhihui, Zhao Lu, Zhu Guoyu
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1. College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, China;
2. College of Water Resource and Hydropower & State Key Laboratory of Hydraulics and Mountain River Engineering,
Sichuan University, Chengdu 610065, China; 3. Chengdu Agricultural Science and Technology Center, Chengdu 610213, China
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| Abstract: |
| 【Objective】Citrus is a major cash crop in the dry-hot valley of the Yuanjiang Basin, and rational water and potassium management is critical for its fruit quality. This paper presents an experimental study on the effects of water-potassium regulation under micro-sprinkler irrigation on citrus photosynthesis at the fruit swelling and maturity stages, as well as the underlying regulatory mechanisms.【Method】The experiment was conducted in an orchard of 12-year-old Bingtangcheng citrus trees from the fruit swelling and maturity stages. Sufficient irrigation combined with local standard potassium application rate served as the control (CK). There were three deficit irrigation treatments: mild water deficit (LD), moderate water deficit (MD) and severe water deficit (SD), with irrigation amount being 85%, 70% and 55% of that in the CK, respectively; and two potassium fertilization treatments: applying 85% (MK) and 70% (LK) of that in the CK. During the experiment, we measured the diurnal dynamics of leaf photosynthetic parameters before and after each re-watering. Structural equation modeling was used to identify the physiological pathways through which water-potassium interaction regulates citrus photosynthesis.【Result】① After rewatering at both growth stages, the daily mean net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), carboxylation efficiency (CE) and instantaneous water use efficiency (WUEi) increased significantly after rewatering due to alleviation of water deficit (p＜0.001), whereas intercellular CO2 concentration (Ci) declined markedly (p＜0.001). The LD treatment was optimal for photosynthesis. ②The effect of potassium application on photosynthesis varied with growing stages. MK significantly increased Pn at the swelling stage but inhibited it at the maturity stage (p＜0.001). ③Stomatal behavior regulated by irrigation amount was the key limiting factor affecting photosynthesis at both the fruit swelling and maturity stages. At the fruit swelling stage, increasing potassium application increased leaf potassium content, synergistically promoting stomatal and non-stomatal processes and ultimately improving photosynthesis. At the maturity stage, increasing potassium application aggravated non-stomatal limitation, thereby inhibiting photosynthesis.【Conclusion】A combination of moderate potassium application and mild deficit irrigation (MK + LD) is optimal at the swelling stage, while mild potassium application combined with mild deficit irrigation (LK + LD) works better at the maturity stage. These irrigation and fertilization strategies improves citrus production in the study region. |
| Key words: citrus; micro-sprinkler irrigation; integrated water-potassium management; diurnal variation of photosynthesis |
