超级稻|产量|时期|硅|硅素吸收、利用效率Effect of Application of Silicon at Different Periods on Grain Yield and Silicon Absorption,Use Efficiency in Super Rice

【目的】明确硅肥施用最佳时期并揭示超级稻硅素高效吸收、利用机理。【方法】采用大田试验，以江苏地区大面积推广种植的粳型超级稻品种武运粳24号和淮稻9号为材料，研究不同时期施硅对水稻产量及其构成因素、主要生育期硅素积累量、硅素阶段积累量、硅素阶段吸收速率、硅素利用效率等的影响，并对产量及其构成因素与硅素吸收、利用效率相关性状进行相关分析。【结果】施硅显著提高产量及其构成因素、主要生育期硅素积累量、硅素阶段积累量、硅素阶段吸收速率和硅肥偏生产力，降低硅素稻谷生产效率，不仅增加了硅素供应量，还能改善土壤的供硅能力，提高土壤有效硅水平，促进水稻对硅素的吸收。随着硅肥施用时期的推迟，产量、穗数、每穗粒数、硅素吸收总量、百公斤籽粒吸硅量、硅素吸收利用率、硅素农学利用率和硅肥偏生产力呈现先增后减的趋势，硅素稻谷生产效率则先降后升，穗数于有效分蘖期追硅表现最高，其它均于有效分蘖临界叶龄期追硅达到最高（低）水平；结实率和千粒重则随着施硅时期的推迟而不断增加，其中抽穗期追硅千粒重达到显著水平；而硅素生理利用率对施硅时期的响应不明显。水稻在各个生育阶段的硅素积累比例，移栽-幼穗分化期为20.69%—29.02%，幼穗分化-抽穗期为47.46%—59.65%，抽穗-成熟期为17.99%—25.52%，幼穗分化-抽穗期＞移栽-幼穗分化期＞抽穗-成熟期，差异极显著。硅素阶段吸收速率表现的趋势与之一致。相关分析表明，水稻产量构成因素的形成与硅素吸收呈现良好的协同增长性，产量与硅素吸收总量呈极显著的正相关，施硅提高幼穗分化-抽穗期硅素阶段吸收速率和硅素阶段积累量是大穗增产的生理基础。【结论】提高硅素阶段吸收速率和硅素阶段积累量，尤其是幼穗分化-抽穗期，能有效提高抽穗期和成熟期硅素积累量及硅素利用效率，进而在稳定提高穗数的基础上，通过主攻大穗，并促进库容的充实，进而达到施硅增产的目的。

Effect of Application of Silicon at Different Periods on Grain Yield and Silicon Absorption,Use Efficiency in Super Rice

【Objective】The objective of this study was to identify the best period for application of Si and the mechanisms of efficient Si absorption and use efficiency in super rice.【Method】A field experiment was conducted with two japonica super rice varieties Wuyunjing24 and Huaidao9 planted on a large scale in Jiangsu region as materials exposed to applied Si at different periods.Grain yield and its components,Si accumulation at the main growth and development stage,periodic Si accumulation,periodic Si uptake rate,Si use efficiency,etc,were investigated.Furthermore,correlation analysis of grain yield and its components and traits associated with Si uptake and use efficiency was studied.【Result】 Applied Si increased grain yield and its components,Si accumulation at the main growth and development stage,periodic Si accumulation,periodic Si uptake rate and partial factor productivity of applied Si,but it decreased Si use efficiency for grain production,significantly.It not only promoted Si supplies,but also improved the ability of providing Si of the soil.Morover,it raised available Si level in the soil and promoted Si absorption of rice.With the delaying periods of applied Si,grain yield,panicles,grains per panicle,total amount of Si absorption,Si uptake per 100kg of grain,Si recovery efficiency,Si agronomic efficiency and partial factor productivity of applied Si increased firstly and then decreased,while Si use efficiency for grain production showed an opposite trend,with applied Si at effective tillering reaching a peak for panicles and critical leaf-age for productive tillers for others.However,seed-setting rate and 1000-grain-weight followed an ascendent tendency accordingly,with 1000-grain-weight of applied Si at heading reaching a significant level,whereas Si physiological efficiency was not significantly correlated with the periods of applied Si.Si accumulation rate of rice were 20.69-29.02% from transplanting to panicle initiation,47.46-59.65% from panicle initiation to heading,17.99-25.52% from heading to maturity,panicle initiation-heading > transplanting-panicle initiation > heading-maturity,significantly,and the periodic Si uptake rate followed the same trend as it.Correlation analysis showed that,grain yield components of rice grew together with Si absorption in phase and there existed significant positive correlations between grain yield and total amount of Si absorption.The increase of periodic Si uptake rate and periodic Si accumulation from panicle initiation to heading improved by applied Si was the physiological basis of increasing grain yield improved by large panicle.【Conclusion】Increase of periodic Si uptake rate and periodic Si accumulation,especially at panicle initiation-heading stage,could increase Si accumulation at heading and maturity satges and Si use efficiency.By achieving large panicle based on stabilizing and raising panicles,and promoting the enrichment of population sink,grain yield could be further improved by application of Si.