【摘要】 【目的】研究分蘖期根际饱和溶解氧对水稻光合及叶绿素荧光参数的调节作用，对提高水稻光能利用效率和优化水稻氧营养栽培理论具有重要意义。【方法】通过水培试验，以水稻、深水稻和旱稻3种生态类型水稻品种为试验材料，设置根际饱和溶解氧（RSDO）和自然生长（CK）2种处理，分别测定水稻分蘖期叶绿素荧光参数、光合特性和干物质积累量等指标。【结果】根际饱和溶解氧条件下，水稻和深水稻叶片光响应曲线下降，且在光强高于500μmol/（m²·s）时，与对照的光响应曲线差距变大。光响应曲线拟合结果表明，根际饱和溶解氧会降低水稻叶片最大净光合速率、表观量子效率（Q）、暗呼吸速率（R_d）和光补偿点（LCP）。3个水稻品种在根际饱和溶解氧环境中光下最大光化学效率（F_v’/F_m’）、实际光化学效率(Φ_PSⅡ)、电子传递速率（ETR）和光化学猝灭系数（q_P）均低于对照，非光化学猝灭（NPQ）和1-q_P高于对照。根际饱和溶解氧能提高水稻夜间呼吸速率（R_n）和胞间CO₂浓度（C_i）。3个水稻品种叶片叶绿素a、叶绿素b以及总叶绿素含量均表现为RSDO<CK，类胡萝卜素和相对电导率表现为RSDO>CK。根际饱和溶解氧显著降低水稻和深水稻的地上部干物质量与叶面积指数，分别较对照下降12.6%、9.4%和9.2%、6.6%，旱稻品种处理间无显著差异。【结论】分蘖期根际饱和溶解氧抑制了水稻叶片光合色素合成，降低了叶片PSⅡ性能和光能利用效率，不利于水稻早期生长；相较于水稻和深水稻，旱稻对根际饱和溶解氧有更好的适应性。更多还原

【Abstract】 【Objective】Studying the regulatory effects of rhizosphere saturated dissolved oxygen （RSDO） during the tillering stage on rice photosynthesis and chlorophyll fluorescence parameters is of great significance for improving rice light energy utilization efficiency and optimizing rice oxygen nutrition cultivation theory.【Method】This study conducted a hydroponic experiment using three ecological types of rice varieties,namely lowland rice,deep-water rice,and upland rice,as experimental materials.Two treatments,rhizosphere saturated dissolved oxygen （RSDO） and natural growth（CK）,were set up to measure chlorophyll fluorescence parameters,photosynthetic characteristics,and dry matter accumulation during the rice tillering stage.【Result】Under the conditions of rhizosphere saturated dissolved oxygen,the leaf light response curves of lowland rice and deep-water rice decreased.When the light intensity exceeded 500μmol/（m²·s）,the difference in curves with the control group increased.The fitting of the light response curve indicates that rhizosphere saturated dissolved oxygen reduces the maximum net photosynthetic rate (P_nmax),apparent quantum efficiency （Q）,dark respiration rate （R_d）,and light compensation point （LCP） of rice leaves.The maximal photochemical efficiency （F_v’/F_m’）,the actual photochemical efficiency (Φ_PSⅡ),electron transfer rate （ETR）,and photochemical quenching coefficient （q_P） of the three rice varieties under RSDO were lower than those of CK,while the non-photochemical quenching （NPQ） and 1-q_P were increased.Rhizosphere saturated dissolved oxygen can increase the nighttime respiration rate （R_n） and intercellular CO₂ concentration （C_i） of rice.The leaf chlorophyll a,chlorophyll b,and total chlorophyll contents of three rice varieties all showed RSDO<CK,while carotenoid content and relative conductivity showed RSDO>CK.The saturated dissolved oxygen in the rhizosphere significantly reduced the aboveground dry matter mass and leaf area index of lowland rice and deep rice,with a decrease of 12.6%,9.4%,and 9.2%,6.6%,respectively,compared to the control.There was no significant difference between the treatments of upland rice varieties.【Conclusion】RSDO inhibits the synthesis of photosynthetic pigments in rice leaves,reduces leaf PSⅡperformance and light energy utilization efficiency,which is not conducive to early rice growth.Compared to lowland rice and deep-water rice,upland rice has better adaptability to RSDO.更多还原