随着水稻育种方法的不断改善和栽培技术的持续创新,再生稻的种植面积及比重在中国水稻生产系统中逐渐增大,已发展成为生产成效显著的水稻种植模式之一。本文结合作者多年来的研究与实践,从作物生理生态学的视角,紧紧围绕再生稻适宜品种筛选及类型划分、机收再生稻的适宜留桩高度与水肥调控、再生稻干物质生产与分配特性及其与产量形成的关系、再生稻根系和再生活力及其与根际微生态特性的关系4个方面,综述了再生稻高产形成及其生理生态机制的研究现状与展望。在推广低留桩再生稻栽培技术时,应重视根际系统的合理调控,促进根际营养供给和腋芽适时萌发及分蘖再生协调发展,实现高再生系数、高再生穗数、高收获指数、高产优质、低碳安全可持续的“四高一低”目标,促进再生稻产业可持续发展。

【目的】探明肥料管理、品种及其互作对再生稻头季和再生季产量和品质的影响,为再生稻高产优质育种和栽培提供理论依据。【方法】采用大田试验的方法,以4个华中地区主推的再生稻品种为材料,设置4种肥料管理方法,分别测定水稻的产量和产量构成因素、稻米品质(加工品质和外观品质)、干物质生产及相关农艺性状等。【结果】相比推荐施肥对照(CK),全生育期施用再生稻专用缓释肥(SRF)使两季施肥的次数从5次减少到3次,而且产量在头季和再生季分别达8.86和6.39 t/hm ²,较CK仅降低了6.2%和9.1%。SRF在头季减产主要归因于较低的结实率,而在再生季减产是每穗颖花数和总颖花数共同下降的结果。促芽肥施与不施对再生季产量没有影响。再生稻两季的加工品质和外观品质主要受品种的影响,肥料处理及其与品种的互作影响很小。相比其他3个品种,甬优4949的头季和再生季产量最高,加工品质和外观品质最好。【结论】施用专用缓释肥和省施促芽肥均能够在不大幅损失稻谷产量的同时减少施肥次数促进再生稻轻简化栽培。

The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice (Oryza sativa L.). Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity (grain yield per cubic meter of irrigation water) by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin + zeatin riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.

发展再生稻是充分利用秋季光热资源,提高稻田产出效益的一条重要途经。根据已报道资料，结合笔者20余年的研究结果，综述了再生稻产量形成特点及关键调控技术研究进展。主要内容包括:（1）头季稻中上部节的再生穗抽穗期比下部抽穗早、着生叶片数少、出叶速度快、生育期短、穗子小、成穗率和结实率较高。头季稻抽穗后光合物质主要供给穗部籽粒灌浆结实，分配给再生芽生长利用的光合物质极少，是齐穗后大量再生芽开始死亡的机理所在；改善头季稻抽穗期间植株行间的光照条件对再生芽生长的促进作用，必须在一定光合物质供给基础上才能显现。头季稻齐穗后品种间再生力取决于头季稻的叶粒比，强再生力品种头季稻单位颖花的绿叶面积占有量较大，其光合产物满足头季稻高产之后剩余量较多，对再生稻高产提供了重要的物质基础，杂交组合间再生力与穗粒数呈极显著负相关关系。（2）水稻品种再生力可分为4级，头季稻及再生稻两季高产品种的库源特征：穗粒数160—190粒、叶粒重比0.0737—0.0827 cm²·mg^-1、有效穗232.12—249.40万/hm²、结实率81.54%—85.74%、千粒重28.58—30.07 g、单穗重4.13—4.43 g。（3）促芽肥提高再生力的作用，是通过施氮延缓了头季稻生长后期绿叶衰老速度，提高母茎叶片全氮含量及其净光合速率，增加叶片当时的光合产物向头季稻穗部输入比例，减少先期贮藏于母茎鞘中光合产物向穗部输入量，相对地提高了母茎鞘干物重而增强再生力。促芽肥对再生稻的作用效果在品种间的表现不尽相同，头季稻穗粒数较多的大穗型品种要提早施用促芽肥并增加施用量，才能获得较高的再生稻产量。利用杂交中稻齐穗期剑叶叶绿素计读数（SPAD值）可预测再生稻促芽肥高效施用量；通过防治纹枯病保护头季稻基部叶片和适度烤田提高根系活力，是再生稻高产的重要保证；头季稻收获期的成熟度与再生力呈极显著正相关，以头季稻完熟期再生芽开始破鞘现青时收割头季稻为宜，留桩高度以保留倒2节并高出5—7 cm处割苗即可。（4）针对目前再生稻生产上存在的主要制约因素，即再生稻开花期的低温危害、再生稻大面积产量不平衡和机械收获头季稻对再生稻生产的不利影响，提出了相应的对策与解决途经。（5）提出再生稻理论与技术的研究重点，包括“生态与农艺措施对头季稻后期冠层性状与再生芽生长的多因素互作机制”、“头季稻收割后再生芽停滞于母茎鞘中的原因及其调控途径”、“提高再生稻氮肥利用效率的技术途径”和“适应机械插秧与机械收割的杂交水稻-再生稻配套技术”4个方面。

优化促芽肥施用技术对于完善再生稻栽培管理技术具有重要意义。本研究以准两优608为材料，通过设置3个施肥时期和3个施肥水平处理，分析促芽肥对“一种两收”再生季水稻产量形成和主要品质性状的影响。结果表明，促芽肥施用时期和施肥水平极显著影响再生稻产量形成，随着促芽肥施用时期的推迟和肥料用量的减少，再生稻产量呈降低趋势。头季稻收割前15 d施用纯N 69.0 kg/hm2的处理再生稻产量最高。该施肥条件下，再生稻碾磨品质较好，垩白粒率低，蛋白质含量高，淀粉含量较低，综合米质较优。生产上，于头季稻收割前15 d施用纯N 69 kg/hm2可以兼顾再生稻高产与优质的目标。

通过使用不同组配的缓控释肥，探讨豫南再生稻轻简化栽培技术的可行性及产量形成原因。结果表明：不同处理下，头季稻增产的主要因素是通过穗粒肥提高了头季稻总颖花量；再生季增产的主要因素是通过促芽肥提高了再生季的叶面积指数和干物质量来提高再生率。精确定量施肥条件下，由于肥料施入及时合理，两季总产量、氮肥贡献率均为最高。新型再生稻专用肥在头季稻生长期分两次施肥，分别作基蘖肥和穗芽肥施入，少施2次肥，两季总产量为13.9 t/hm²，较精确定量施肥产量减少1055 kg/hm²，人工及肥料成本较精确定量施肥减少990元/hm²，净收入较精确定量施肥减少1478元/hm²，较精确定量施肥仅低3.5%。可根据当地的用工情况使用新型再生稻套餐肥，最终达到稳产增收的目的。

【目的】 研究头季氮素穗肥和促芽肥运筹对再生稻再生芽生长、干物质积累及产量形成的影响及可能途径。【方法】 采用裂裂区设计，品种为主区(丰两优香1号和两优6326)，2个头季穗肥为副区(N₁，30 kg/hm²；N₂，60 kg/hm²)，3个再生季促芽肥为副副区(T₁、T₂和T₃分别为0、50和100 kg/hm²)，考查在不同氮肥运筹下两品种再生芽生长状况、干物质积累与分配、产量及产量构成因子。【结果】 头季高氮素穗肥对丰两优香1号头季产量无显著影响，显著提高两优6326头季产量，对两品种再生力和再生季产量无显著影响。增施促芽肥显著降低两品种头季齐穗前茎鞘干物质转运量和收获指数，提高不同节位再生芽芽长、活芽数和再生力，促进再生季齐穗后干物质积累，提高了再生季产量。此外，头季氮素穗肥和促芽肥对再生季产量具有显著交互作用。丰两优香1号在N₁T₃处理下周年产量最高(14.46 t/hm²)，两优6326在N₂T₂处理下周年产量最高(14.44 t/hm²)。单茎再生芽长、活芽数和芽生长速率与头季齐穗后干物质积累量呈显著正相关，与头季收获指数和头季齐穗前干物质转运量呈显著负相关，与再生力和再生季产量呈显著正相关。【结论】 头季高氮素穗肥对丰两优香1号和两优6326再生季产量没有显著影响，促芽肥施用可促进两品种再生芽生长，提高再生力和再生季产量，但过高施用量并没有进一步提高产量。头季穗肥和促芽肥互作显著影响再生季产量。施用促芽肥可通过增加头季茎鞘干物质积累来促进再生芽生长、再生季干物质积累与成穗，从而提高再生力和再生季产量。再生稻生产中应合理运筹穗肥和促芽肥以实现较高的再生季和周年产量。低头季穗肥和高促芽肥、高穗肥高促芽肥可分别实现丰两优香1号、两优6326周年高产。

【目的】阐明常规淹灌和干湿交替灌溉下,不同施肥模式对水稻关键生育期氮吸收转运、氮素利用率和稻田氮转化特征的影响及其与水稻产量的关系,以期为绿色高效稻田水肥管理提供理论依据。【方法】 2018&#x02014;2019年连续进行2年,以杂交籼稻中浙优1号为供试材料,设常规淹灌（FI）、干湿交替（AWD）2种灌溉模式以及空白对照（N₀）、常规施氮（PUN₁₀₀）、减氮20%（PUN₈₀）、缓控释复合肥减氮20%+生物炭（CRFN₈₀-BC）和稳定性复合肥减氮20%+生物炭（SFN₈₀-BC）5种施肥模式,对比分析了不同灌溉和施肥模式下水稻产量、氮吸收利用及稻田氮转化特征。【结果】（1）与FI灌溉模式相比,AWD灌溉显著增加了各处理水稻产量（P80</sub>-BC和SFN₈₀-BC处理水稻产量分别达9 721 kg&#x000b7;hm^-2、10 056 kg&#x000b7;hm^-2（2018年）和9 492 kg&#x000b7;hm^-2、9 907 kg&#x000b7;hm^-2（2019年）,且均显著高于PUN₈₀和PUN₁₀₀处理（P0</sub>、PUN₁₀₀和PUN₈₀处理相比,AWD灌溉显著提高了抽穗前CRFN₈₀-BC和SFN₈₀-BC处理水稻茎鞘和叶片氮累积量、抽穗至成熟期茎鞘和叶片氮转运量及其氮转运贡献率;同时,显著增加了成熟期0&#x02014;30 cm剖面稻田可溶性总氮（dissloved total N,DTN）和NO₃^-含量,并有效降低稻田渗滤液中DTN、NH₄⁺和NO₃^-质量浓度。（3）相关分析结果表明,水稻产量与营养生长期叶片和茎鞘氮累积量,抽穗后氮转运量和氮转运贡献率,成熟期水稻氮素利用率和稻田氮有效性显著正相关,表明适宜的水氮管理能协同促进氮素在水稻中的吸收和运转畅通,增加稻田氮素有效性,进而显著提高水稻产量和氮素利用率。【结论】综合2年水稻产量与氮素吸收利用、稻田氮素有效性特征,干湿交替灌溉下生物炭配施缓控释/稳定性复合肥能有效提高水稻高产群体构建、氮吸收转运和氮素利用效率,并降低稻田氮淋溶损失。

Lodging-resistant rice (Oryza sativa) cultivars usually show slow grain filling when nitrogen is applied in large amounts. This study investigated the possibility that a hormonal change may mediate the effect of water deficit that enhances whole plant senescence and speeds up grain filling. Two rice cultivars showing high lodging resistance and slow grain filling were field grown and applied with either normal or high amount nitrogen (HN) at heading. Well-watered and water-stressed (WS) treatments were imposed 9 days post anthesis to maturity. Results showed that WS increased partitioning of fixed (14)CO(2) into grains, accelerated the grain filling rate but shortened the grain filling period, whereas the HN did the opposite way. Cytokinin (zeatin + zeatin riboside) and indole-3-acetic acid contents in the grains transiently increased at early filling stage and WS treatments hastened their declines at the late grain filling stage. Gibberellins (GAs; GA(1) + GA(4)) in the grains were also high at early grain filling but HN enhanced, whereas WS substantially reduced, its accumulation. Opposite to GAs, abscisic acid (ABA) in the grains was low at early grain filling but WS remarkably enhanced its accumulation. The peak values of ABA were significantly correlated with the maximum grain filling rates (r = 0.92**, P < 0.01) and the partitioning of fixed (14)C into grains (r = 0.95**, P < 0.01). Exogenously applied ABA on pot-grown HN rice showed similar results as those by WS. Results suggest that an altered hormonal balance in rice grains by water stress during grain filling, especially a decrease in GAs and an increase in ABA, enhances the remobilization of prestored carbon to the grains and accelerates the grain filling rate.

To understand the effect of water stress on the remobilization of prestored carbon reserves, the changes in the activities of starch hydrolytic enzymes and sucrose-phosphate synthase (SPS) in the stems of rice (Oryza sativa L.) during grain filling were investigated. Two rice cultivars, showing high lodging-resistance and slow remobilization, were grown in the field and subjected to well-watered (WW, psi(soil)=0) and water-stressed (WS, psi(soil)=-0.05 MPa) treatments 9 d after anthesis (DAA) till maturity. Leaf water potentials of both cultivars markedly decreased during the day as a result of WS treatment, but completely recovered by early morning. WS treatment accelerated the reduction of starch in the stems, promoted the reallocation of prefixed (14)C from the stems to grains, shortened the grain filling period, and increased the grain filling rate. More soluble sugars including sucrose were accumulated in the stems under WS than under WW treatments. Both alpha- and beta-amylase activities were enhanced by the WS, with the former enhanced more than the latter, and were significantly correlated with the concentrations of soluble sugars in the stems. The other two possible starch-breaking enzymes, alpha-glucosidase and starch phosphorylase, showed no significant differences in the activities between the WW and WS treatments. Water stress also increased the SPS activity that is responsible for sucrose production. Both V(limit) and V(max), the activities of the enzyme at limiting and saturating substrate concentrations, were enhanced and the activation state (V(limit)/V(max)) was also increased as a result of the more significant enhancement of V(limit). The enhanced SPS activity was closely correlated with an increase of sucrose accumulation in the stems. The results suggest that the fast hydrolysis of starch and increased carbon remobilization were attributed to the enhanced alpha-amylase activity and the high activation state of SPS when the rice was subjected to water stress.

A major challenge in rice (Oryza sativa L.) production is to enhance water use efficiency (WUE) and maintain or even increase grain yield. WUE, if defined as the biomass accumulation over water consumed, may be fairly constant for a given species in given climate. WUE can be enhanced by less irrigation. However, such enhancement is largely a trade-off against lower biomass production. If WUE is defined as the grain production per unit amount of water irrigated, it would be possible to increase WUE without compromising grain yield through the manipulation of harvest index. Harvest index has been shown to be a variable factor in crop production, and in many situations, it is closely associated with WUE and grain yield in cereals. Taking rice as an example, this paper discussed crop management techniques that can enhance harvest index. Several practices such as post-anthesis controlled soil drying, alternate wetting and moderate soil drying regimes during the whole growing season, and non-flooded straw mulching cultivation, could substantially enhance WUE and maintain or even increase grain yield of rice, mainly via improved canopy structure, source activity, sink strength, and enhanced remobilization of pre-stored carbon reserves from vegetative tissues to grains. All the work has proved that a proper crop management holds great promise to enhance harvest index and, consequently, achieve the dual goal of increasing grain production and saving water.