Effect of Source-Sink Manipulation on Photosynthetic Characteristics of Flag Leaf and the Remobilization of Dry Mass and Nitrogen in Vegetative Organs of Wheat

The photosynthetic characteristics of flag leaf and the accumulation and remobilization of pre-anthesis dry mass（DM） and nitrogen（N） in vegetable organs in nine wheat cultivars under different source-sink manipulation treatments including defoliation（DF）, spike shading（SS） and half spikelets removal（SR） were investigated. Results showed that the SS treatment increased the photosynthetic rate（Pn） of flag leaf in source limited cultivar, but had no significant effect on sink limited cultivar. The SR treatment decreased the Pn of flag leaf. Grain DM accumulation was limited by source in some cultivars, in other cultivars, it was limited by sink. Grain N accumulation was mainly limited by source supply. The contribution of pre-anthesis dry mass to grain yield from high to low was stem, leaf and chaff, while the contribution of pre-anthesis N to grain N from high to low was leaf, stem and chaff. Cultivars S7221 and TA9818 can increase the contribution of remobilization of DM and N to grain at the maximum ratio under reducing source treatments, which may be the major reason for these cultivars having lower decrease in grain yield and N content under reducing source treatments.     

Effects of Delayed Nitrogen Topdressing on Grain Yield and Photosynthetic Characteristics of Flag Leaves of Wheat

Four wheat cultivars were used to study the effects of delayed nitrogen topdressing on popula-tion structure, grain yield and photosynthetic characteristics of flag leaves under high-yielding conditions. Theresults showed that the nitrogen topdressing delayed from overwintering-turning green stage (N1) to turninggreen-jointing stage(N2 ) and jointing-booting stage(N3 ) decreased ineffective tiller in spring, retarded the de-cline of green leaf area and chlorophyll content in late life span, promoted photosynthetic ability of flag leavesand significantly increased the grain yield. N3 treatment was suitable for most wheat cultivars except the geno-types with higher single spike productivity and less ears in unit area.     

Physiological basis for the differences of productive capacity among tillers in winter wheat

The quality or structure of a wheat population is significantly affected by the compositions of tillers. Little has been known about the physiological basis for the differences of productive capacity among tillers. Two winter wheat cultivars, Shannong 15(SN15) and Shannong 8355(SN8355), were used to investigate the differences of productive capacity among tillers and analyze the physiological mechanisms that determine the superior tiller group. Low-position tillers(early initiated tillers) had a higher yield per spike than high-position tillers(late initiated tillers) in both cultivars, which was due to their more grain number per spike, more fertile spikelet per spike, less sterile spikelet per spike and higher grain weight. According to cluster analysis, tillers of SN15 were classified into 2 groups: superior tiller group including main stem(0), the first primary tiller(I) and the second primary tiller(II); and inferior tiller group including the third primary tiller(III) and the first secondary tiller(I-p). Tillers of SN8355 were classified into 3 groups: superior tiller group(0 and I), intermediate tiller group(II and III) and inferior tiller group(I-p). In comparison with other tiller groups, the superior tiller group had higher photosynthetic rate of flag leaves, higher antioxidant enzyme(SOD, POD and CAT) activities and lower levels of lipid peroxidation in leaves, higher grain filling rate in both superior and inferior grains during grain filling, higher single-stem biological yield and larger single-stem economic coefficient. Correlation analysis showed that yield per spike was positively and significantly correlated with the flag leaf photosynthetic rate, grain filling rate, the antioxidant enzyme activities and soluble protein content(except for SN15 at 5 days post-anthesis(DPA)) of flag leaf, the single-stem biological yield, and the single-stem economic coefficient. Remarkable negative correlation was also found between yield per spike and MDA content of flag leaf. These results suggested that superior tiller group had stronger leaf photosynthetic capacity, more predominance in terms of grain filling, slower senescence rate, higher biological yield and larger economic coefficient, and therefore, showed greater productive capacity than other tiller groups.     

氮素追肥后移对小麦籽粒产量和旗叶光合特性的影响

用4个小麦品种，研究了高产水平下氮素追肥后移对小麦群体结构、籽粒产量和旗叶光合特性的影响，在基肥量相同的情况下，每公顷追施氮素150kg，追肥由越冬至返青期（N1），延迟到返青至拔节期（N2）和拔节至孕穗期增加籽粒产量的作用，其效果N3处理优于N2处理。     

小麦品种改良过程中物质积累转运特性与产量的关系

【目的】探明小麦品种改良过程中物质积累与转运特性及其与产量形成的关系,为选育高产品种、制定育种目标提供理论依据。【方法】选用32个20世纪不同年代代表性小麦品种于2007-2009年进行大田试验,分析小麦不同生育时期干物质生产与积累转运特性的演进特征及其与产量的关系。【结果】随着品种改良进程,籽粒产量和收获指数逐步提高,而20世纪60年代品种生物产量显著降低随后保持稳定;开花期叶面积、叶面积指数及旗叶光合速率逐步提高,为花后物质积累提供了物质和能量来源。品种改良显著提高了小麦拔节前和开花后物质积累量及群体生长速率,但降低了拔节至开花期积累量和生长速率;提高了花前干物质转运量、转运率及贡献率,但降低了花后干物质贡献率。小麦籽粒产量与拔节前及开花后干物质积累量、生长速率及花前干物质贡献率显著正相关,与拔节开花阶段物质积累量和生长速率及花后干物质贡献率显著负相关。【结论】品种改良提高了小麦物质生产能力和生产效率,协调了不同生育阶段物质积累,平衡了花前和花后干物质对籽粒的贡献。因此,提高拔节前营养生长、增加花后干物质积累和花前物质转运是小麦产量改良的重要物质基础,也是今后小麦高产育种的重要目标。     

栽培模式对稻茬小麦籽粒产量、氮素吸收利用和群体质量的影响

【目的】为稻茬小麦优质、高产、高效协同栽培提供理论与技术支撑。【方法】2017—2018和2018—2019年在江苏苏北的睢宁和苏中的邗江与仪征,分别设置传统（TCP）、高产（HCP）、节肥（RFCP）和节肥增密（IDCP）4种栽培模式,研究不同模式间籽粒蛋白质含量、产量、氮效率、经济效益的差异,明确高产、高效模式及其产量构成、群体质量和氮素吸收转运特征,探明产量、氮效率与农艺生理性状间关系,进而揭示高产高效协同实现途径。【结果】受年度和地点间生态条件差异的影响,栽培模式对籽粒产量、经济净效益、氮效率的影响不尽相同。不同栽培模式下籽粒蛋白质含量均>12.5%,其中HCP和RFCP下达13%—14%。2018年度,籽粒产量和经济净效益均以IDCP最高,较TCP分别提高31.5%—33.5%和104.4%—239.1%,其次为HCP和RFCP。2019年度,籽粒产量以HCP最高,较TCP提高8.1%—13.2%,其次为RFCP和IDCP;此外,IDCP因施肥少,较TCP稳定或增加了经济净效益。可见,TCP相对低产、低效益、低氮效率;HCP可稳定高产,且蛋白质含量高;IDCP最具高产、...     

Postponed and reduced basal nitrogen application improves nitrogen use efficiency and plant growth of winter wheat

Excessive nitrogen(N) fertilization with a high basal N ratio in wheat can result in lower N use efficiency(NUE) and has led to environmental problems in the Yangtze River Basin, China. However, wheat requires less N fertilizer at seedling growth stage, and its basal N fertilizer utilization efficiency is relatively low; therefore, reducing the N application rate at the seedling stage and postponing the N fertilization period may be effective for reducing N application and increasing wheat yield and NUE. A 4-year field experiment was conducted with two cultivars under four N rates(240 kg N ha–1(N240), 180 kg N ha–1(N180), 150 kg N ha–1(N150), and 0 kg N ha–1(N0)) and three basal N application stages(seeding(L0), fourleaf stage(L4), and six-leaf stage(L6)) to investigate the effects of reducing the basal N application rate and postponing the basal N fertilization period on grain yield, NUE, and N balance in a soil-wheat system. There was no significant difference in grain yield between the N180 L4 and N240 L0(control) treatments, and the maximum N recovery efficiency and N agronomy efficiency were observed in the N180 L4 treatment. Grain yield and NUE were the highest in the L4 treatment. The leaf area index, flag leaf photosynthesis rate, flag leaf nitrate reductase and glutamine synthase activities, dry matter accumulation, and N uptake post-jointing under N180 L4 did not differ significantly from those under N240 L0. Reduced N application decreased the inorganic N content in the 0–60-cm soil layer, and the inorganic N content of the L6 treatment was higher than those of the L0 and L4 treatments at the same N level. Surplus N was low under the reduced N rates and delayed basal N application treatments. Therefore, postponing and reducing basal N fertilization could maintain a high yield and improve NUE by improving the photosynthetic production capacity, promoting N uptake and assimilation, and reducing surplus N in soil-wheat systems.     

土壤肥力和灌水量组合对不同类型小麦光合特性及产量的影响

旨在为小麦节水高产栽培提供理论依据。在池栽条件下,研究了不同土壤肥力和灌水量组合对中筋小麦‘济麦22’和强筋小麦‘济麦20’旗叶净光合速率(Pn)、叶绿素荧光参数及产量构成的影响。2种小麦开花后各生育时期旗叶的光合速率Pn 值、叶绿素荧光参数Fv/Fm 值（PSⅡ最大光化学量子产量）和ФPSⅡ 值（PSⅡ实际光化学量子产量）均随着土壤肥力和灌水量的增加而提高,但土壤肥力因素对上述光合特性指标的影响大于灌水方式因素。随着土壤肥力的提高,Pn 和ФPSⅡ 开始下降的时间逐渐向后延迟,提高土壤肥力有利于减轻环境胁迫对光合的抑制作用。对于2 种小麦的产量和产量构成的影响,土壤肥力和灌水方式之间具有补偿效应。在土壤肥力较高的条件下,2 种小麦限量灌溉和充分灌溉之间产量差异并不显著。培肥地力可以减缓小麦灌水不足导致的光合性能指标的下降,维持生育后期较高的光合产物积累水平。     

施氮量对花后高温胁迫后小麦同化物积累、转运及产量的影响

【目的】明确不同施氮量对高温胁迫后小麦同化物积累和转运的影响及其生理基础,以期为小麦抗逆稳产栽培提供技术和理论依据。【方法】于2018—2019年在济南和济阳两地进行,以济麦44为材料,田间搭建高温棚进行高温胁迫处理,设置2个温度处理（CK：未胁迫,H：花后高温胁迫）,3个氮肥水平（低氮N1：180 kg·hm^-2,常规氮N2：240 kg·hm^-2,高氮N3：300 kg·hm^-2）。通过分析小麦花前同化物质的转运、成熟期同化物质的积累与分配、叶片与籽粒中蔗糖合成酶在同化物转运中的作用,阐明了不同施氮量对花后高温胁迫后小麦籽粒产量形成的影响机制。【结果】不同施氮量对高温胁迫后小麦的减产率影响不同,N1处理减产率为54.78%（济南）和50.19%（济阳）,N2处理为24.05%（济南）和25.29%（济阳）,N3处理为54.49%（济南）和44.13%（济阳）。高温胁迫后,与N1和N3处理相比,N2处理成熟期同化物积累量、花前营养器官同化物向籽粒中转运量和转运率、花后同化物积累量和积累率、同化物向籽粒中的分配比例均显著增加;N2处理旗叶SPAD值、蔗糖合成酶SS-Ⅱ合成方向活性和籽粒蔗糖合成酶SS-Ⅰ分解方向活性增加。【结论】本试验条件下,施氮量为240 kg·hm^-2可以显著减缓高温胁迫后旗叶衰老,维持旗叶中SS-Ⅱ和籽粒中SS-Ⅰ较高的酶活性,保持较高的同化物合成能力和向籽粒中的转运能力,提高同化物向籽粒中的积累量和分配比例,降低高温胁迫后小麦籽粒产量的损失率。     

地力水平和种植密度对冬小麦子粒产量和氮素利用率的影响

[目的]旨在探讨不同地力水平下冬小麦子粒产量和氮素利用率对种植密度的响应并分析子粒产量和氮素利用率协同提高的途径,为制定冬小麦高产高效栽培管理措施奠定理论基础。[方法]试验在高、低两个地力条件下进行,以大穗型冬小麦品种泰农18为试验材料,设置135万、270万和405万株/hm23个种植密度,研究地力水平和种植密度对子粒产量及构成、氮素吸收效率、氮素利用效率和氮素利用率等相关指标的影响。[结果]高地力水平下子粒产量高于低地力水平,但氮素利用效率和氮素利用率均较低。各地力水平下,提高种植密度可显著提高冬小麦穗数和子粒产量,提高成熟期地上部氮素积累量和氮素吸收效率,但氮素收获指数和氮素利用效率随种植密度上升呈下降趋势,增密对子粒含氮量无显著影响。各地力水平下增密后氮素吸收效率增加的幅度远高于氮素利用效率降低的幅度,所以氮素利用率随着种植密度的提高而呈上升趋势。低地力水平下增密后子粒产量和氮素利用率提高的幅度均高于高地力地块。[结论]在高、低地力水平下,增加种植密度均可提高子粒产量和氮素利用率,有利于实现冬小麦的高产高效栽培,且低地力水平下增密后子粒产量和氮素利用率的增幅高于高地力水平。     

青海高原春小麦高产育种的商榷

在青海高原生态条件下,通过增加春小麦叶片净光合速率提高同化能力,以大穗大粒增大库的贮积能力,以矮秆配合良好光合性能和大贮积能力提高收获指数,使品种的源、流、库协调发展,达到培育高产品种的目的。     

花后喷肥对不同穗型小麦旗叶光合速率及籽粒产量的影响

为了探讨不同穗型小麦品种对花后喷肥的反应,选用大穗型和多穗型小麦品种为试验材料,研究了花后混喷多种肥料对2种穗型小麦品种旗叶光合速率、干物质积累及籽粒产量的影响。结果表明:花后喷肥可提高旗叶净光合速率,增加单茎地上干物质积累,多穗型品种豫麦49旗叶净光合速率和地上干物质积累增幅均大于大穗型品种宿2001。喷肥后茎节单位长度干重增加,茎节贮存物质有所增加,以宿2001较为明显。混喷多种肥料后2种穗型小麦品种的籽粒产量均显著高于对照,其中,豫麦49增产7.41%,宿2001增产6.35%,品种间差异不明显。     

Growth traits and nitrogen assimilation-associated physiological parameters of wheat(Triticum aestivum L.) under low and high N conditions

In this study, 14 wheat cultivars with contrasting yield and N use efficiency(NUE) were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and high N conditions. Under deficient-N, the cultivars with high N uptake efficiency(UpE) and high N utilization efficiency(UtE) exhibited higher plant biomass, yields, and N contents than those with medium and low NUEs. The high Up E cultivars accumulated more N than other NUE type cultivars. Under sufficient-N, the tested cultivars showed similar patterns in biomass, yield, and N content to those under deficient-N, but the varietal variations in above traits were smaller. In addition, the high Up E cultivars displayed much more of root biomass and larger of root length, surface area, and volume than other NUE type cultivars, indicating that the root morphological traits under N deprivation are closely associated with the plant biomass through its improvement of the N acquisition. The high Ut E cultivars showed higher activities of nitrate reductase(NR), nitrite reductase(NIR), and glutamine synthetase(GS) at stages of seediling, heading and filling than other NUE type cultivars under both low and high N conditions. Moreover, the high Up E and Ut E cultivars also displayed higher photosynthetic rate under deficient-N than the medium and low NUE cultivars. Together, our results indicated that the tested wheat cultivars possess dramatically genetic variations in biomass, yield, and NUE. The root morphological traits and the N assimilation enzymatic acitivities play critical roles in regulating N accumulation and internal N translocation under the N-starvation stress, respectively. They can be used as morphological and biochemical references for evaluation of Up E and Ut E in wheat.     

不同冬小麦品种产量和氮素吸收利用效率差异

【目的】研究新疆南疆不同冬小麦品种产量、氮素吸收利用效率的差异及对氮肥的响应,为小麦氮高效育种、氮高效品种选择及氮肥优化施用提供参考依据。【方法】设置3个施氮量,选择新疆南疆种植12个品种（系）为材料,研究不同氮肥水平下不同小麦品种的产量、氮素积累量、氮素利用率、氮素吸收效率和氮素利用效率等指标差异。【结果】随着施氮量的增加不同品种收获穗数、穗粒数增加,千粒重降低,氮素积累量和产量增加;氮素利用率、氮素吸收效率和氮素利用效率随着施氮量的增加而降低。氮素利用率较高品种为新冬40号,新冬60号,15/6317。氮高效品种达到高氮效率的途径不同,在不施氮（N_o）条件下新冬40号,新冬60号,15/6317氮素利用率高主要是氮素吸收效率和氮素利用效率的共同作用,以氮素利用效率为主;在施氮条件下新冬60号和新冬40号在氮素吸收效率高来自其较高氮素吸收能力,而15/6317氮素利用率较高是氮素吸收效率和氮素利用效率的共同作用。【结论】不同品种达到氮高效的途径不同,针对不同小麦品种的氮素吸收和利用特性进行调控,提高小麦氮素吸收和利用效率。     

冬小麦品种选育若干问题探讨

为提高育种预见性和选择效率,对小麦株型与冠层、株高、单位面积穗数等几个选择指标进行了探讨。认为株高80～90cm,旗叶较宽、较短,面积较小,挺而上冲,旗叶、倒二叶、倒三叶的长度依次加长,叶基角和开张角依次加大。株型从生长前期到生长后期由紧凑到松散有一定动态变化的中间型品种更易实现高产稳产;现代品种要在保持较高收获指数的基础上,注重生物产量、单位面积粒数、穗粒数／旗叶面积、穗粒重／旗叶面积的选择。     

小麦品种旗叶和穗下节间的生理特性及其与籽粒充实的关系

<正> 引言不少研究证明小麦开花后的光合作用为籽粒提供绝大部分的干物质,其中旗叶的贡献最大。MohiuddiN等(1980)发现冬小麦旗叶和穗部绿色面积功能期与籽粒产量和粒重为正相关;与每穗粒数为负相关。DhimaN等(1980)也证明旗叶面积同籽粒产量有密切关系。小麦籽粒的产量与其充实度有关。我省多数地区年度间存在小麦籽粒充实不良、千粒重低     

花后喷肥对不同筋型小麦品种旗叶光合速率、籽粒产量和品质的影响

为了探讨不同筋型小麦品种对花后喷肥的反应,选用强筋、中筋和弱筋三种类型小麦品种为试验材料,研究了花后混喷多种肥料对三种筋型小麦品种旗叶光合速率、籽粒产量及品质性状的影响。结果表明:花后喷肥可提高旗叶净光合速率,强筋型小麦品种郑麦366旗叶净光合速率增幅大于中筋型品种太空6号和弱筋型品种豫麦50。喷肥后茎节单位长度干重减少,茎节贮存物质向穗部转移量增加,以郑麦366较为明显。混喷多种肥料后三种筋型小麦品种的籽粒产量均显著高于对照,籽粒容重、吸水率、蛋白质、湿面筋等品质指标均显著高于对照,而降落值因小麦筋型不同而变化。     

干旱胁迫下不同抗旱性小麦品种产量形成与水分利用特征

在移动防雨棚条件下,以晋麦47(抗旱性强)、偃展4110(抗旱性弱)和矮抗58(抗旱性中等)为材料,在足墒播种、安全越冬基础上,设置拔节~成熟期持续干旱(W1)、开花~成熟期干旱(W2)、拔节~成熟期供水适宜(W3)3种水分处理,研究了干旱胁迫对不同抗旱性冬小麦品种产量形成和水分利用的影响。结果表明:供水适宜时3个品种的产量和水分利用效率皆无显著差异,干旱胁迫显著降低了各品种产量,降幅表现为晋麦47矮抗58偃展4110。与偃展4110相比,晋麦47干旱时生育前期耗水较多,物质积累量较大,单位面积总粒数较高;而在产量形成期(开花~成熟)叶片蒸腾速率较低,耗水量较小,水分生产效率较高,贮藏物质转运对籽粒的贡献率较高,最终获得较高的产量和水分利用效率。矮抗58在花后干旱条件下具有较高的物质生产能力和花前贮藏物质贡献率,相对产量也较高。综合研究认为,干旱环境下早期的吸水能力和生长能力强、群体库容量大、花前贮藏物质贡献率和花后水分生产效率高是抗旱高产品种的重要特征。     

节水灌溉对节水抗旱水稻品种产量的影响及生理基础

【目的】探明节水抗旱水稻品种在节水灌溉条件下产量形成特点及生理基础。【方法】2个节水抗旱品种旱优113（杂交籼稻）和旱优8号（杂交粳稻）及2个当地高产品种两优培九（两系杂交籼稻）和扬辐粳8号（粳稻）种植于土培池和大田,自移栽后10 d至成熟设置常规灌溉和节水灌溉处理。【结果】与常规灌溉相比,当地高产品种在节水灌溉条件下产量显著降低,两种灌溉方式间的节水抗旱品种产量无显著差异。节水灌溉显著减少灌溉水量,提高灌溉水生产力（产量/灌溉水量）,节水抗旱品种灌溉水生产力增幅大于当地高产品种。与当地高产品种相比较,节水抗旱品种在节水灌溉条件下的相对分蘖数和每穗颖花数（节水灌溉分蘖数或颖花数/常规灌溉分蘖数或颖花数）较多,结实率较高;整个生育期绿叶面积持续期长,抽穗期根重较高、抽穗后根系氧化力、根系和叶片中细胞分裂素（玉米素+玉米素核苷）含量、剑叶光合速率和籽粒中蔗糖合酶和腺苷二磷酸葡萄糖焦磷酸化酶活性、抽穗期至成熟期的干物质积累量、茎中非结构性碳水化合物的运转率和收获指数较高。土培池与大田试验结果趋势一致。【结论】在节水灌溉条件下节水抗旱品种比当地高产品种可获得较高的产量和水分利用效率;节水抗旱品种在节水灌溉条件下较好的根系性能和地上部植株较强的生理活性是其高产与水分高效利用的重要生理基础。     

长期遮光对冬小麦群体及单叶光合特性的影响

[目的]研究长期弱光对冬小麦（Triticum aestivum L.）群体光合速率（CAP）以及上3叶特别是旗叶光合特性的影响。[方法]以耐弱光性不同的冬小麦品种扬麦158和扬麦11为材料,设不遮光（S0）、从拔节至成熟期遮去小麦冠层自然光强的22%（S1）和33%（S2）3个处理,测定小麦CAP、上3叶的光合速率（Pn）、旗叶叶绿素含量以及籽粒产量。[结果]扬麦158和扬麦11 CAP随遮光强度的增强而显著下降;长期弱光下,旗叶Pn显著下降,倒2叶Pn无明显变化,而倒3叶Pn则显著上升,从而部分地补偿了旗叶Pn的降低。该补偿效应因遮光强度和品种而异：S1处理的补偿效应大于S2处理,扬麦158的补偿效应大于扬麦11。在旗叶光合速率高值持续期内,长期遮光降低了扬麦158和扬麦11总叶绿素、叶绿素a和b的含量,以及叶绿素a/b值。[结论]弱光下,旗叶叶绿素a含量以及叶绿素a/b值下降引起其Pn显著降低,从而使得CAP明显降低,最终导致籽粒产量显著下降。该研究可为长江中下游地区的小麦生产提供重要的理论依据。