不同穗型小麦小花生长发育及同化物分配变化的差异

为了解小麦小花发育成粒特性与同化物分配间的关系,以大穗型品种周麦16和多穗型品种豫麦49-198为材料,分析了两种穗型小麦小花发育成粒特性及同化物分配的差异。结果表明,周麦16的小花退化、败育速率较豫麦49-198缓慢,且在小穗结实率、小花结实率和可孕小花结实率上均高于后者。在小花发育中后期,大穗型品种周麦16转移到穗部的同化物比多穗型品种豫麦49-198多。经相关分析,花期完善小花(有完整绿色花药的小花)数与穗干重、穗氮积累量、茎干重、茎氮积累量呈微弱的正相关,与穗茎干重比、穗茎氮积累量比呈显著正相关,与穗干重/穗氮积累量比呈极显著正相关。周麦16的穗茎干重比、穗茎氮积累量比显著高于豫麦49-198,二指标均与穗干重/穗氮积累量比呈极显著正相关。进一步分析发现,周麦16的开花期单位面积完善小花数与成熟期单位面积粒数分别较豫麦49-198增加3.85%和4.65%,且品种间差异均达到极显著水平。     

施氮对冬小麦旗叶蔗糖含量及籽粒淀粉合成的影响

为给小麦高产优质栽培提供依据,在高产田块上,设置三个氮肥用量(90、180、270 kg N·ha-1),研究了施氮对两个冬小麦品种豫麦49和太空6号开花后旗叶蔗糖、籽粒淀粉合成动态及产量的影响.结果表明,施氮对两品种旗叶蔗糖含量及SPS酶活性、籽粒蔗糖含量及SS酶活性、籽粒淀粉积累速率及产量均有显著影响,但影响特点因品种而异.豫麦49在施氮量90～270 kg·ha-1范围内,随施氮量的增加,旗叶和籽粒的蔗糖含量、SPS和SS活性以及籽粒淀粉积累速率均呈增加趋势.太空6号在施氮90～180 kg·ha-1范围内,上述指标在灌浆中后期与施氮量呈正相关;当氮肥用量增加至270 kg·ha-1时,各项指标均下降.相关分析表明,两供试冬小麦品种籽粒蔗糖含量与旗叶蔗糖含量分别呈极显著和显著正相关(豫麦49 r=0.703**,太空6号r=0.530*);豫麦49籽粒淀粉积累速率与其籽粒蔗糖含量和SS活性之间呈显著和极显著正相关(r=0.578*,r=0.701**),太空6号籽粒淀粉积累速率仅与籽粒SS之间呈显著的正相关(r=0.625*),而与籽粒蔗糖含量之间相关性不显著(r=0.121).施氮量270 kg·ha-1时,豫麦49产量最高;太空6号需氮量相对较低,产量达最大值时的施氮量为180 kg·ha-1.     

分蘖期和拔节期干旱对小麦主茎和分蘖穗粒形成的影响

为明确分蘖期和拔节期干旱对小麦穗粒数形成的影响,在盆栽条件下以豫麦49（小穗型）和扬麦13（中穗型）为材料,研究了小麦分蘖期和拔节期不同程度干旱条件下主茎和分蘖的穗粒形成特征。结果表明,分蘖期和拔节期轻度干旱对小麦穗粒数的影响不显著,而分蘖期重度干旱显著降低了主茎穗粒数,拔节期重度干旱和分蘖期+拔节期重度干旱均可显著降低主茎和分蘖的穗粒数,且对主茎穗粒数的影响更大。分蘖期重度干旱处理显著降低了主茎小穗分化数与可见小花数,但对分蘖无影响。拔节期重度干旱和分蘖期+拔节期重度干旱处理可显著降低小穗结实率、可见小花数、可孕小花数及可孕花结实率,进而导致小麦穗粒数显著降低。分蘖期重度干旱处理导致小麦主茎穗粒数的降低并未影响主茎的产量,拔节期重度干旱和分蘖期+拔节期重度干旱处理导致小麦主茎穗粒数下降均造成产量显著降低。因此,小麦营养生长期适度干旱不影响小麦主茎和分蘖小穗及小花发育,从而能够维持较高的穗粒数和产量,可以适度的进行节水灌溉,提高水分利用效率。     

栽培管理模式对冬小麦小花发育与结实特性的影响

为探索提高小麦穗粒数的技术途径与栽培管理模式,在大田试验条件下,以豫麦49-198为材料,研究了不同栽培管理模式(当前农民栽培管理模式、节本增效栽培管理模式、超高产栽培管理模式、高产高效栽培管理模式)对小麦小花发育动态模式与结实特性的影响。结果表明,不同栽培管理模式下,随播后累积生长度日的增加,小麦小花的分化动态均符合二次曲线方程模式,退化和败育动态均符合一次方程模式,但不同栽培管理模式间小花发育方程参数上存在明显差异;与当前农民栽培管理模式相比,其他3种栽培管理模式均显著增加了可孕小花数和最终结实粒数,并显著提高了小穗、小花和可孕花的结实率,其中以高产高效栽培管理模式分化小花数、可孕小花数和最终结实粒数提高的幅度最大。     

施氮量对超高产冬小麦花后光合特性及产量的影响

为给冬小麦超高产栽培中氮肥合理运筹提供参考依据,于2007-2008年在河南温县、兰考两试验点,以两个具有超高产潜力的冬小麦品种豫麦49和兰考矮早八为供试材料,在全生育期施氮0、90、180、270 和360 kg N ·hm-2（底施和拔节期追施各半）的条件下,研究了施氮量对冬小麦光合特性、干物质积累和籽粒产量的影响。结果表明,两试验点施氮量180和270 kg·hm-2处理的籽粒产量均达到了每公顷9 000 kg以上的水平,高于其他施氮处理,与不施氮和90 kg N ·hm-2处理间差异均达显著水平。进一步分析发现,与其他处理相比,180和270 kg·hm-2处理提高了两个小麦品种开花后旗叶光合速率和SPAD值,进而增加了花后干物质积累量。两试验点的施氮处理对大穗型品种兰考矮早八成穗数影响不显著,而施氮量180和270 kg·hm-2处理显著提高了多穗型品种豫麦49的成穗数;两品种穗粒数和粒重均表现为不施氮和90 kg N ·hm-2处理显著低于适宜施氮量（180和270 kg N ·hm-2）处理。两品种在两试验点获得最高产量的施氮量不同,豫麦49和兰考矮早八分别在270和180 kg·hm-2获得最高产量。由此可见,在本试验条件下,两个品种在施氮量180~270 kg·hm-2、基施和拔节期比例5∶5条件下,在稳定足够穗数的基础上,增加穗粒数,促进花后物质积累量,提高粒重,可实现超高产。     

孕穗期叶面喷素对小麦穗粒数和粒重的影响

为探讨孕穗期叶面喷素对小麦穗粒数和粒重的调控效应,于2014-2015年在河南农业大学科教示范园区进行试验,以半冬性品种豫麦49-198为供试材料,在小麦拔节后25d(4月6号),以清水为对照,叶面分别喷施硼砂(B)、6苄基腺嘌呤(6-BA)、6-BA+B、奇善宝(QSB)、双增1号(CPD),对不同喷素条件下小花败育速率和籽粒灌浆进程及其成熟后小麦穗部性状进行观察和分析。结果表明,与对照相比,不同喷素处理均能降低小花的败育速率,显著增加小麦不同部位的小穗粒数和粒重。对小麦各部位小穗粒数的促进效果,以CPD处理对小麦下、中部小穗粒数提高幅度最大,分别较对照增加了1.95个和4.85个;对不同部位小穗粒重的促进效果,也以CPD处理效果最佳,使小麦下、中和上部小穗粒重分别较对照提高了11.97%、5.87%和9.32%。     

普通小麦及其近缘物种花序、小穗和小花的形态结构分析

花的发育影响着种子的发育。普通小麦是三大粮食作物之一,但对小麦花序发育的研究滞后于水稻和玉米。为揭示小麦花发育的机理,本研究采用体视镜观察、扫描电子显微镜观察和组织切片后光学显微镜观察等方法,对普通小麦及其近缘物种一粒小麦、拟斯卑尔脱山羊草、粗山羊草、二粒小麦以及二穗短柄草的花序、小穗和小花形态结构进行了系统观察和分析比较。结果表明,普通小麦与二倍体小麦、二粒小麦表现出一定差别:普通小麦每个小穗形成8~10朵小花,但在发育后期,大多数小花退化不育,每个小穗只有3~4朵小花能够形成种子;二倍体小麦和二粒小麦的小穗结构与普通小麦类似,但每个小穗发育形成3~5朵小花,小花数目明显减少。与普通小麦相似,二穗短柄草每个小穗同样分化形成多朵小花,不同的是,二穗短柄草的大多数小花发育正常,是可育的。以上这些研究结果暗示小麦具有巨大的增产潜力。     

春季氮肥和多效唑调控对小麦生育和产量的影响

为明确春季调控措施对冬小麦生长发育和籽粒产量的影响,以冬小麦品种石新828为材料进行田间试验,4个处理分别为:起身期追全部氮肥(除基肥外,下同)并叶面喷多效唑(N1);起身期追2/3氮肥并喷多效唑+拔节期追1/3氮肥(N2);起身期追1/3氮肥+拔节期追2/3氮肥(N3);拔节期追全部氮肥(N4)。生育期间测定群体和个体生育特性,成熟期调查产量性状。结果表明,N1和N2处理小麦拔节期的总茎数、叶面积指数(LAI)和干物质积累量均显著高于N4和N3处理。孕穗期N4和N3处理小麦的总茎数、LAI和干物质积累量显著高于N1和N2处理。开花到成熟期各处理的总茎数、LAI和干物质积累量差异均不显著。孕穗期前,不同处理的株高差异不显著,孕穗期后,N4处理的株高最高,且显著高于N1处理。各处理基部节间直径和中上部节间长的差异不显著,N4处理基部第一节间长度显著大于其他处理。随追氮时期前移或前期施氮量增多,不孕小穗数减少,结实小穗和穗粒数增加,N1比N4处理不孕小穗数显著减少,结实小穗和穗粒数显著增多。N1处理小麦成熟期的千粒重最高,且显著高于N4处理。N1处理的籽粒产量最高,且显著高于N3和N4处理。起身期追氮配合多效唑调控,可以获得比拔节期追氮更高的穗粒数和千粒重,从而获得更高的产量。     

关于十个冬小麦品种小穗分化速度及其小穗分化持续期的研究

每平方米穗数,每穗小穗数,每小穗粒数和粒重是冬小麦产量组成的四个因素.小花发育的速度可影响最终的每小穗粒数.Whingwiri等推断,顶端小穗形成后产生的小花不能结实,因此顶端小穗的形成意味着小穗数和小花数已经确定.并认为小花与穗轴之间的维管束系统的发育随小花分化而开始,顶端小穗形成后维管束发育即受抑制,此后形成的小花不能结实.每个小穗上最初两朵小花是在顶端小穗形成前产生的,约97%能结实;第四朵小花很少结实,第三朵处于两者之间,约72%不能结实.     

不同小麦品种钾素营养特性的差异

选用27个小麦品种为材料，通过盆栽试验的方法，研究了各品种的施钾响应度，以明确不同小麦品种间钾素营养特性的差异。结果表明，供试小麦品种钾效率及其对施钾响应度存在显著的基因型差异，27个品种可分为低效低响应型、低效高响应型、高效低响应型、高效高响应型4种类型。其中，豫麦25号、郑州9023、豫麦9号和豫麦34为第一种类型，豫麦41号、丰优7号、济麦2号、郑麦9405、新麦11、郑农16和豫麦68为第二种类型，豫麦18、温麦8号、豫麦69、豫麦60、新矮早958、郑州9689、周麦16、高优503、豫展1号、新麦9号、兰考3号、兰考6号、豫麦49、兰考4号、偃师4110为第三种类型，太空6为第四种类型。在钾胁迫奈件下小麦成熟期生物学产量及其施钾响应度与小麦籽粒产量及其施钾响应度之间均呈极显著的正相关关系，可作为评价不同小麦品种钾效率高低和对施钾效应大小的参考指标。在供试土壤条件下。不同小麦品种钾效率与其钾利用效率呈显著的正相关。     

冬小麦碳氮积累、转运和籽粒产量对小花发育期追氮的响应

为给冬小麦高产优质栽培过程中氮肥的合理调控提供参考依据,通过河南郑州和兰考两点大田试验,分别在总施氮量240和180 kg·hm^-2下,以全部基施为对照,进行基施和追施各50%施氮处理［追肥时期分别在返青期(二棱末期)、返青后10 d(护颖原基分化期)、20 d(雌雄蕊原基分化期)和30 d(雌蕊凹期)］,探讨了小花发育期施氮对两种穗型冬小麦碳、氮积累和转运及产量构成的影响。结果表明,在小花发育期追施氮肥均有利于花前碳、氮的贮藏积累和转运,且兰考矮早8品种贮藏碳、氮转运对籽粒的贡献率分别高于对照处理4.49和3.98个百分点,而豫麦49198品种分别高于对照处理1.68和0.47个百分点;两个品种花前贮藏氮素转运对籽粒的贡献率分别高于碳素42.97和38.47个百分点。在本试验条件下,在小花雌雄蕊原基分化期追施氮肥增加了兰考矮早8的千粒重和豫麦49198的穗粒数,且追肥处理的穗粒数、千粒重和籽粒产量显著高于其他处理,氮素积累和转运的增加也显著提高了籽粒蛋白质含量和产量。根据本研究结果,在总施氮量180~240 kg·hm^-2下,采取基施和小花雌雄蕊原基分化期追施氮肥各50%,提高了籽粒产量和蛋白质产量。     

Initiation and Development of Spikelets and Florets in Wheat as Influenced by Shading and Nitrogen Supply at the Spikelet Phase

Abstract

The spike of the main culm in winter wheat was examined by scanning electron microscopy from the double ridge to 6 days after the terminal spikelet stage to quantitatively evaluate the effects of shading and nitrogen supply at the spikelet phase on the numbers of spikelets and floret primordia, and the development of florets. Positional differences on a spike in grain setting at maturity were also investigated. Nitrogen supply affected neither the rate nor duration of spikelet initiation, the number of spikelets remaining unchanged. Although nitrogen supply positively affected the initiation and development of florets, it slightly reduced the grain weight per spike at maturity due to a decrease in the number of grains per spike and the reduced grain weight. These results suggested that under the field condition, nitrogen supply at the double ridge stage is too late to have a significant effect on the spikelet number, and might induce competition for nitrogen between the main culm and tillers, or induce mutual shading between plants, resulting in lighter grain weight per spike. Shading decreased the rate of spikelet initiation, resulting in a significant decrease in spikelet number. The initiation and the development of florets were also decreased by shading. Lower non -structural carbohydrate content at the terminal spikelet stage suggested that the limited assimilate supply by shading was likely responsible for the decreases in the initiation and development of spikelets and florets.     

硫氮配施对弱筋小麦品种豫麦50籽粒产量和淀粉性状的影响

为了研究硫肥和氮肥配合施用对弱筋小麦产量和淀粉品质性状的影响,在大田条件下,设置了不同肥与硫氮肥配合施用处理,研究其对弱筋小麦品种豫麦50产量和淀粉品质性状的影响.结果表明,硫肥和氮肥对小麦产量有正效应,施硫显著提高了小麦成穗数,施氮显著提高了穗粒数和小穗结实率;施硫提高了直链淀粉含量,极显著提高了淀粉直/支比,氮肥对淀粉品质的效应与硫肥相反;硫肥、氮肥及其互作对淀粉品质性状的平均贡献率分别为12.72%、51.31%、35.98%,硫、氮配施对淀粉品质仍有正效应.处理组合中,在施氮量240 kg/ha条件下,施硫量为100 kg/ha处理的产量最高,施硫量为20 kg/ha处理的直链淀粉含量最低,施硫量为60 kg/ha处理的淀粉直/支比最低,分别为8 378.96 kg/ha、11.71%和0.2059.表明达到最高产量和最佳淀粉品质的硫氮配施量并不完全一致.     

Radiation effects on potential number of grains per spike and biomass partitioning in two- and six-rowed near isogenic barley lines

The critical period for yield determination in barley (Hordeum vulgare L.) is situated in the pre-heading phases. During the latest part of the critical period one of the most important yield components (i.e. the number of grains per spike) is set in two- and six-rowed barley. In wheat, much is known about the role of the spike in assimilate acquisition for the establishment of grains per spike, but not in barley. This paper evaluates how biomass partitioning between vegetative and reproductive organs impacts floret development and primordia survival in response to radiation during different periods in the crop cycle, in barley lines. Field experiments were carried out using two- and six-rowed near isogenic barley lines differing only in spike type. Shading treatments were applied at different periods during the crop cycle (from 60 to 15 days before and after heading) reducing the intercepted radiation (ca. 70%). Dynamics of floret primordia initiation and mortality and of floret development for different spikelet positions along the spike were measured, and biomass partitioning between vegetative and reproductive structures was calculated.

Pre-heading shading reduced fertile florets per spike (P < 0.001). In the immediate pre-heading treatment, distal floret primordia could not reach a fertile floret stage due to a low rate of floral development.

The amount of assimilates partitioned to the spike at heading affected the number of fertile florets per spike in both barley types. However, when spike biomass at heading was corrected by nitrogen concentration, the fitness of the relationship did not improve in relation to the first one. In relative terms, radiation restrictions during the immediate pre-heading phase increased the amount of biomass partitioned to the growing spike.     

Spring wheat response to timing of water deficit through sink and grain filling capacity

Water and nitrogen (N) availability are the main factors influencing crop growth globally. Poorly distributed or insufficient water for crop growth requirements decreases yields in drought-prone areas such as those with a Mediterranean type environment. Cereal grain yield is a complex trait of interrelated components: plants per unit land area, spikes per plant, spikelets per spike, grains per spikelet, and single grain weight (SGW). The effect of water limitation and timing on development of yield components was studied in detail at the spike level in spring wheat (Triticum aestivum L.) cultivar Amaretto. An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was arranged in a large greenhouse (20 m × 30 m), with the use of standard field-trial machinery. Automated blackout curtains were used to control day length, which was set to correspond to that at 40°N. With watering treatments, two N application rates (60 and 120 kg N ha⁻¹) were used to investigate the N effect and potential watering × N interaction on yield formation and realisation. The water deficit effect exceeded the effect of N on fertile floret and grain number and SGW. DR1 strongly reduced the number of fertile florets and grains, whereas terminal drought reduced the number of grains per spike. Resuming the watering at pollination markedly enhanced photosynthesis, and hence grain filling capacity, resulting in the highest SGW in DR1. Enhancement in availability of key resources was associated with reduced rate of fertile floret and grain abortion, which resulted in higher grain to fertile floret ratio in DR1. Spikelets in the mid-section of the spike dominated yield formation in all treatments. In DR1 this was especially emphasised as 53% of the grain yield was produced in spikelets 4–6, whereas in DR2 and CONT this was 45 and 41%, respectively. Grains in proximal position in the spikelets produced about 80% of the spike grain yield, the proportion being slightly higher in stressed plants and plants receiving 60 kg N. No marked N × water deficit treatment interaction occurred for any of the measured parameters.     

小麦穗光合对不同花位籽粒及颖壳的影响

为明确小麦穗光合对产量形成的贡献，充分发挥穗光合在提高产量中的作用，以小麦新品种百农矮抗58为材料，采用铝铂纸包穗的方法，研究了高群体小麦穗部：屯合对籽粒和颖壳的影响。结果表明，穗光合对小麦产量的贡献率为14．43％；穗光合对千粒重的贡献大于对穗粒数的贡献；对不同花位籽粒的贡献存在较大的差异，对第1、2、3花位籽粒千粒重均有贡献，但是影响第4花位籽粒的发育；穗光合也是维持颖壳正常生理代谢所必需的。说明选育深绿穗品种也是提高小麦产量的一个重要途径。     

不同专用小麦氮素同化及根际土壤氮素转化的特点

为了解不同专用小麦氮素同化及根际土壤氮素转化的特点,利用盆栽试验比较分析了强筋型小麦豫麦34、中筋型小麦豫麦49和弱筋型小麦豫麦50叶片谷氨酰胺合成酶（GS）活性、游离氨基酸和可溶性蛋白含量及其根际土壤微生物和土壤酶活性的差异。结果表明,随生育进程,功能叶GS活性先升后降,豫麦34于开花期达到最大,豫麦49和豫麦50则在花后14 d达到高峰;叶片游离氨基酸含量呈先降后升再降的趋势,在花后14 d有一小高峰,除拔节期外,各时期均表现为豫麦34>豫麦49>豫麦50;除拔节期外,各时期叶片可溶蛋白含量均表现为豫麦34>豫麦50>豫麦49。根际土壤反硝化细菌活性在开花期较低,在其他时期均表现为豫麦34>豫麦49>豫麦50。硝化作用在拔节期和花后28 d品种间差异显著;豫麦34和豫麦49的亚硝化作用在开花期有小幅上升,豫麦50则在开花期达到最低值;土壤蛋白酶及脲酶活性在生育后期较大;不同专用小麦根际土壤铵态氮和硝态氮含量仅在拔节期差异显著。     

超高产冬小麦四种微量元素的积累及其与产量性状的关系

为了明确超高产冬小麦锰、锌、铜、硼的吸收积累特点及与产量相关性状的关系,于2005-2006年冬小麦成熟期测定了不同小麦品种产量相关性状及植株和籽粒中锰、锌、铜、硼的含量与积累量。结果表明,成熟期不同冬小麦品种植株和籽粒中4种元素的含量和积累量存在不同程度的差异,但都表现为锰>锌>铜>硼。植株锰积累量与穗粒数呈显著正相关,植株锰含量和积累量与单株成穗数呈显著负相关。植株和籽粒锌含量和积累量与每穗小穗数、结实小穗数和穗粒数呈正相关,与不孕小穗数呈负相关,但相关均未达到显著水平。植株铜含量与每穗小穂数、结实小穗数、穗粒数和产量均为正相关,且相关达到显著或极显著水平。植株铜积累量与总小穗数、结实小穗数呈显著正相关,与不孕小穗数呈显著负相关。植株硼积累量与产量达到显著正相关水平。综合分析可知,4种微量元素在增加产量和优化产量构成因素中起着不同的作用,在小麦生产中应针对具体的限制因素确定不同微量元素肥料的施用技术。