摘要:根际氧是影响稻田土壤环境和水稻根系生理代谢的重要环境因子，已有的关于水稻根际氧的综述多从低氧或缺氧胁迫的角度展开，随着技术的进步，越来越多的****在水稻栽培中实施了主动的根际增氧措施，取得了一定的研究成果。根际增氧显著影响了水培水稻根系形态和结构，使其呈现细而长的特征，增氧条件下水稻根系形态、结构及其功能需求间存在内在的一致性；根际增氧对不同生育时期水稻的根系活力均有明显的促进作用，其增幅从10%到150%不等，并存在明显的品种间差异；从水稻根系形态、生理活性以及根部氮素形态转化等多个方面来看，增氧处理有利于水稻根系吸收氮素，但其对水稻氮素积累量的影响则与增氧处理方式和程度有关，过度增氧抑制了水稻植株对氮的利用，从而限制了其生物量的增加，反过来抑制了对氮的吸收。水稻对根际增氧的响应规律并非其对低氧和缺氧胁迫响应规律的简单倒转，饱和氧处理下水稻生物量和产量的剧烈降低表明了水稻对富氧响应的复杂性。探索根际增氧对三叶期前水稻幼苗的影响，完善根际增氧对水稻氮代谢的影响研究，并量化水稻田间需氧量，探索简单易行的苗期增氧措施，对进一步完善水稻育秧理论，改进水稻育秧技术具有重要意义。
关键词:水稻/
根际增氧/
根系形态/
根系活力/
氮代谢
Abstract:Rhizosphere oxygen is an important environmental factor that influences paddy filed environment and physiological metabolism of rice root. Existing reviews about rhizosphere oxygen are usually from the perspectives of hypoxia or anoxia stress. In recent years, more and more researchers implemented active oxygen-increasing in rice cultivation and obtained a large number of results. Rhizosphere oxygen-increasing significantly affects the morphology and structure of hydroponic rice root, making rice roots slender and elongated. It may be due to the reduced demand for preventing the leakage of oxygen and invasion of reducing substances, which means there is no need to form a barrier against radial O2 loss, so the thickness of outer layer cell wall of root is smaller than that under hypoxic or anoxic stress conditions. It's suggested that there is an internal consistency among the root morphology, structure and functional requirements of rice under aerobic condition. Rhizosphere oxygen-increasing significantly promotes root vigor with an increment from 10% to 150% and with great differences among varieties. From the aspects of root morphology, physiological activity and transformation of nitrogen form in root-zone, e.g., the increased fine root, the raised root vigor, the enhanced nitrification under aerobic treatment, rhizosphere oxygen-increasing is beneficial for rice roots to uptake nitrogen, however its effects on nitrogen accumulation in rice is complex and related with the method and degree of oxygen-increasing treatment. Excessive oxygen-increasing inhibits the use of nitrogen in rice plants, thus limiting the increase in biomass, which in turn inhibits the absorption and accumulation of nitrogen. Response of rice to oxygen-increasing is not a simple reverse of that to hypoxia or anoxia stress, the dramatic yield decrease of rice under oxygen-saturation treatment demonstrated the complexity of rice response to oxygen-enrichment environment. It's proposed that exploring the effects of rhizosphere oxygen-increasing on pre-third-leaf stage rice seedling and rice nitrogen metabolism, quantifying the demand for oxygen of field rice and seeking feasible oxygen-increasing measures in seedling stage was of great significance for further improving rice seedling raising technology and theory.
Key words:Rice/
Rhizosphere oxygen-increasing/
Root morphology/
Root activity/
Nitrogen metabolism
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