【摘要】 【目的】探明不同耐低磷水稻品种内源激素水平的差异及其与产量和磷吸收利用的关系。【方法】以2个强耐低磷品种(耐低磷指数>0.9)和2个弱耐低磷水稻品种(耐低磷指数<0.5)为材料，采用水培种植，设置低磷(磷浓度为标准营养液中磷浓度的1/20,0.401 mg/L)和正常磷(8.02 mg/L)两个处理。【结果】与正常磷相比，低磷显著降低了两类品种的产量和磷的吸收量，但提高了磷素干物质生产效率和磷产谷利用率。在低磷处理下，与弱耐低磷品种相比，强耐低磷品种具有较高的产量、磷吸收量、磷利用效率、根干质量、地上部干质量和根系氧化力，根和叶中具有较高的生长素、玉米素及其核苷、脱落酸、茉莉酸类(茉莉酸和茉莉酸甲酯)、油菜素甾醇(24-表油菜素内酯和28-高油菜素内酯)含量，根中具有较高的独脚金内酯含量。这些激素水平与产量、磷吸收利用率、根干质量、地上部干质量和根系氧化力呈显著或极显著正相关；而根和叶中乙烯释放速率和1-氨基环丙烷-1-羧酸含量表现为强耐低磷品种显著低于弱耐低磷品种，并与产量和磷利用率显著或极显著负相关。随机森林分析表明，在各类激素中茉莉酸类和油菜素甾醇对产量和磷利用率的贡献最大。【结论】在低磷胁迫下，强耐低磷品种内源激素之间的平衡，特别是较高的茉莉酸类和油菜素甾醇含量，有利于优化根系形态，维持较高的根系活性，促进磷的吸收和利用，获得较高产量。更多还原

【Abstract】 【Objective】This study aimed to investigate the differences in endogenous hormone levels among rice varieties with varying tolerance to low phosphorus (P) stress and their relationship with grain yield, P uptake, and utilization. 【Method】Two rice varieties with strong tolerance to low P (STVs, low P tolerance index > 0.9) and two varieties with weak tolerance to low P (WTVs, low P tolerance index < 0.5) were grown hydroponically under normal P level (NP, 8.02 mg/L) and low P level (LP, 0.401 mg/L). 【Results】Compared to NP, LP significantly reduced grain yield and P uptake in both types of rice varieties but increased dry matter production per unit of P and internal P use efficiency. Under LP treatment, the STVs exhibited higher grain yield, P uptake and utilization efficiency, root dry weight, and root oxidation activity compared to the WTVs. Additionally, the STVs had higher content of indole-3-acetic acid, zeatin + zeatin riboside, abscisic acid, jasmonates (jasmonic acid and methyl jasmonate), and brassinosteroids (24-epibrassinolide and 28-homobrassinolide) in both roots and leaves, as well as higher content of strigolactones in roots. These hormone levels were significantly or very significantly positively correlated with grain yield, P uptake and utilization efficiency, root dry weight, and root oxidation activity. Furthermore, a lower ethylene emission rate and lower 1-aminocyclopropane-1-carboxylic acid content were observed in both roots and leaves of the STVs compared to the WTVs, which were significantly or very significantly negatively correlated with grain yield and P use efficiency.Random forest analysis indicated that jasmonates and brassinosteroids served as the predominant contributors to grain yield and P use efficiency. 【Conclusion】 Under LP stress, the balance among endogenous hormones, particularly higher levels of jasmonates and brassinosteroids, plays a key role in optimizing root morphology, maintaining higher root activity, promoting P uptake and utilization, and achieving a higher grain yield in STVs.更多还原