施氮对夏玉米顶部籽粒早期发育及产量的影响

以夏玉米杂交种郑单958为材料,对不同施氮水平下顶部籽粒的早期发育状况及产量进行了研究。结果表明,施氮明显促进关键酶活性的增强,促进顶部籽粒的早期发育。当施氮量为180 kg/hm²时,顶部籽粒的酸性蔗糖转化酶（AI）、中性蔗糖转化酶（NI）、蔗糖合成酶（SS）、腺苷二磷酸葡萄糖焦磷酸化酶（ADPGase）、淀粉     

内蒙古平原灌区高产春玉米(15 t hm-2以上)产量性能及增产途径

针对内蒙古平原灌区春玉米高产(15 t hm^-2以上)群体产量进一步提高难度大,产量挖潜途径不明确的问题,采用产量构成因素分析与产量性能参数分析相互验证的方法,在4年52点次高产(15 t hm^-2以上)群体产量构成因素分析的基础上,设计不同品种密度试验,研究增密对不同品种群体产量性能的影响,明确不同类型玉米品种的增产途径和栽培调控的主攻方向。结果表明,穗数和穗粒数是决定高产(15 t hm^-2以上)群体产量的主要因素。实现15 t hm^-2以上群体的产量结构为：穗数(7.08~9.60)×10⁴穗,穗粒数477~654粒,千粒重324.7~388.7 g,穗粒重168.9~234.0 g。其合理群体结构衡量指标是LAI_max在6.5以上,平均LAI在5左右,收获期LAI在3.5以上。高秆大穗型品种理想的产量结构是：67 500~75 000穗 hm^-2,每穗610~640粒,千粒重380 g左右,单穗粒重220~240 g,产量大于15 t hm^-2;株高适中的中小穗型品种,理想产量结构是： 75 000~97 500穗 hm^-2,每穗520~600粒,千粒重340~355 g,单穗粒重180~220 g,产量在16.5 t hm^-2以上。密度增加促进平均作物生长率(MCGR)和单位面积总籽粒数(TGN)的增加进而提高产量,但增密后平均净同化率(MNAR)降低导致穗粒数显著降低并限制了TGN的提高潜力。通过增密为主的结构性挖潜,使得群体功能的增益大于个体生产性能的降低,实现高产(15 t hm^-2以上),属于“得失性补偿增产”;在优化群体结构的基础上,提高个体生产能力,突破个体库容降低的限制,进行功能性挖潜,实现群体结构和个体功能协同增益的“差异性补偿增产”,是产量进一步提高的重要途径。     

Effects of Nitrogen and Plant Density on Growth, Yield and Chemical Composition of Two Winter Wheat (Triticum aestivum L.) Cultivars

A field study was conducted on the winter wheat cultivars Arminda and Okapi , using two seed rates (80 and 160 kg/ha) and three N applications (40, 80 and 120 kg/ha).
The cultivars did not differ in total dry matter production but did differ in grain yield. The difference in grain yield was mainly attributable to a higher harvest index (HI).
Increased plant density reduced HI; it resulted in more shoots per m², but in a lower grain yield. The reduction in grain yield was caused by fewer kernels per ear and a lower 1000-grain weight in both cultivars.
A higher rate of N increased total dry matter production and grain yield, except in Okapi at the high plant density. The number of kernels per ear increased, but 1000-grain weight fell.
The higher the N applications, the higher the N-content of the roots was.
Total N yield was greater in Arminda than in Okapi. The cultivars differed in the amount of nitrogen they took up after anthesis.
The content of water-soluble carbohydrates (WSC) differed between the cultivars, N treatments and growth stages. Carbohydrate formed before anthesis accounted for 23 % of Arminda's grain yield and for 10 % of Okapi's grain yield.
The content of cell-wall constituents (CWC) depended on cultivar, growth stage and the rate of the N dressing. Differences in CWC were more pronounced in Arminda than in Okapi. During leaf, stem and ear development there was a strong increase in content and amount of CWC. Concomitantly, WSC decreased. This implies that a large consumption of WSC is necessary for the formation of CWC. The competition for the WSC, necessary for CWC and shoot and ear development influences kernel initiation. Per unit of dry matter Okapi contained more CWC than Arminda. This was not in agreement with differences in straw sturdiness.     

Yield Responsiveness in Two- and Six-Rowed Barley Grown in Contrasting Nitrogen Environments

Two‐ and six‐rowed barley with different intrinsic ability to produce tillers and kernels per ear, would differ in responsiveness to nitrogen availability with environmental improvements. Two field experiments were carried out to elucidate how nitrogen supply (N₄₀ and N₁₅₀) affects yield and its components in two‐ and six‐rowed barley. High nitrogen increased aboveground dry matter at anthesis, by improving cumulative solar radiation intercepted by the crop, determining an increased dry‐matter production at maturity without changes in harvest index. In both barley types, variations in grain yield were explained by changes in kernels per unit land area rather than by differences in the average kernel weight. However, changes in the number of kernels were due to variations in the number of ears per m² in two‐rowed barley and the number of kernels per ear in six‐rowed barley. Ears per unit area showed a greater responsiveness in two‐ than in six‐rowed barley due to a higher nitrogen supply treatment, associated with their intrinsic higher tillering capacity, while the number of kernels per ear was more responsive in six‐ than in two‐rowed types. The fact that responses to nitrogen by the number of kernels per unit land area in two‐ and six‐rowed barley is better explained by different yield sub‐components, allows the speculation that the critical period for yield determination would differ between barley types.     

Effects of Temporary Water Stress After Anthesis on Grain Yield and Yield Components in Different Tiller Categories of Two Spring Wheat Varieties

Water stress might limit grain yields of cereals under humid conditions. The objective of this study was to investigate the effect of a temporary water shortage at three different stages after anthesis on the grain yield and yield components of different tiller categories in two spring wheat varieties. A pot experiment with controlled water supply and rain shelters was conducted in 1984 and 1985 in Kiel, N. W. Germany. The water stress (pF 2.9 to 3.4) was imposed either between anthesis to early milk development of the caryopsis (WS1) (EC 65 to EC 72 according to Z adoks scale), early milk development to late milk development of the caryopsis (WS2) (EC 72 to EC 77) and late milk development to maturity (WS3) (EC 77 to EC 92). The control had a constant water supply throughout the growing season of between pF 2.2 to 2.5.
The water stress treatment WS1 significantly reduced the single plant yield by 10 % (1984) and 15 % (1985) in one variety (Selpek), whereas the other variety was unaffected. The response of both varieties to the two later treatments was smaller and insignificant.
In the first year the yield decrease in the variety Selpek after the WS1 treatment was mainly caused by a lower number of ears per plant compared with the untreated control (WS0). In the second year (1985) additionally a lower grain weight of the second category shoots caused by a reduction of the number of kernels per ear contributed to the decrease of the single plant yield. The yield component thousand grain weight could not compensate for the reduction in the number of kernels per ear.     

群体密度对提型杂种小麦产量性状及其杂种优势的影响

本文研究了群体密度对提型杂种小麦产量性状及其杂种优势的影响.结果表明:各性状在密度间都存在着显著差异.单株穗数、穗粒数和千粒重随密度增加而下降,籽粒产量与密度呈二次抛物线关系.平均穗粒数和单株穗数的杂种优势在产量杂种优势形成中的直接作用是低密度高于高密度;千粒重的杂种优势在产量杂种优势形成中的直接作用是低密度低于高密度;通过对杂种小麦产量及杂种优势标准化联立方程组求解和对产量回归方程求导的方法,确定了杂种小麦的适宜密度范围为每亩8.5～13万株,最后提出了适当降低杂种小麦密度应采取的栽培措施.     

Response of Triticale Grain Yield and Yield Components to Number of Cuttings in a Mediterranean Environment

In six field experiments conducted over 2 years, the effect of one or two cuttings on grain yield of triticale (× Triticosecale Wittmack) were investigated. In addition, the relationships between triticale grain yield its components were analysed.
Grain yield of the uncut plots invariably exceeded the plots with one or two cuttings, regardless of the environment or year. The reductions in grain yield caused by one cutting ranged from 27 % to 60 % under rainfed conditions and 18 % to 20 % under irrigation. With two cuttings the reduction was 45 % to 70 % for rainfed, and 35 % to 48 % for irrigated conditions.
The yield components which most influenced grain yield of triticale under cutting treatment were the number of ears m⁻² in all six experiments and the number of grains per ear under rainfed conditions. At the rainfed sites in 1989 cuttings diminished the number of ears m⁻² mainly by increasing plant mortality. Nevertheless, at the rainfed sites of 1990 and at the irrigated site of both years, the reduction in the number of ears m⁻² with cuttings was due principally to a lower survival of tillers per plant.     

小麦超高产单株种子生产潜力及相关性状的研究

为探讨小麦单株种子生产潜力及相关性状特征,以57个不同基因型F2代小麦超高产单株为材料,对超高产单株产量性状、相关性状间的相关、通经和回归关系进行了分析。结果表明：（1）超高产单株（≥80 g/单株）田间选择概率为0.00518%;（2）株穗数、穗粒数、千粒重、结实小穗数、穗粒重和容重与单株产量呈显著正相关,不孕小穗数呈显著负相关,株高、穗长和千粒重相关不显著;（3）株穗数对单株产量的直接贡献最大,决定单株产量的65.33%,穗粒数、穗粒重、千粒重、株粒数分别决定单株产量的19.92%、18.15%、13.72%和5.6%。≥80 g/株的单株田间选择概率为0.00518%。     

高产夏玉米产量性能特征及密度深松调控效应

以现代高产玉米品种中单909和郑单958为试验材料, 于2010-2011年在河南新乡设置种植密度与耕作方式田间试验, 研究夏玉米高产群体产量性能参数变化及主要栽培措施调控效应。结果表明, 中单909相比郑单958显著增产11.36%, 穗粒数(KN)、千粒重(KW)极显著增加(P<0.01), 生育天数(D)、收获指数(HI)和收获穗数(EN)无明显差异(P>0.05); 平均叶面积指数(MLAI)、光合势在灌浆后期增加更为显著, 平均净同化率(MNAR)显著增加(P<0.05), 而干物质积累最大生长速率、生长速率最大时的生长量、平均生长速率、活跃生长期均明显提高。进一步分析产量性能参数间相互关系, EN与MLAI呈极显著正相关(P<0.01), KN和KW与MNAR呈极显著正相关(P<0.01), 而MNAR、KN、KW与MLAI呈极显著负相关(P<0.01)。中单909比郑单958增产可能是产量性能参数差异补偿的结果。中单909在高密度下具有较高的MLAI、MNAR和KN, 获得最高产量的群体密度比郑单958高27.3%; 深松耕作方式下, 中单909和郑单958分别增产13.0%和8.7%, 主要表现为, MNAR和KN显著增加, MLAI和D无明显变化, HI、EN、KW增加幅度在不同品种间表现不一致, 表明土壤深松条件下密植(9.50×10⁴株 hm^-2)是目前夏玉米高产重要技术途径之一。综上, 密植夏玉米高产群体产量性能特征参数为MLAI 3.05~3.55、MNAR 4.80~6.27 g m^-2 d^-1、D 109~111、HI 0.50~0.52、EN 9.60~10.38×10⁴穗 hm^-2、KN 352.0~370.1粒、KW 314.7~315.9 g, 可以实现11 250~12 000 kg hm-2以上的产量。     

黔西北山区小麦产量构成因素及高产育种途径研究

采用多元回归、多元相关分析法，分析了黔西北山区小麦产量构成因素，结果表明，在三要素中，决定产量的主导因子是穗数，其次是千粒重，最后是穗粒数，在此基础上提出了本区小麦高产育种应走大穗较多穗型求高产的育种途径，为本区小麦产量进一步提高提供了理论指导。     

灌浆初期低温对春玉米产量构成的影响研究

旨在研究东北地区低温冷害对春玉米灌浆的影响,确定春玉米灌浆期间冷害影响农业气象指标。用人工气候室通过模拟自然低温（平均15℃、17℃、19℃）方法,对灌浆初期盆栽春玉米进行（3、5、7天）胁迫处理。结果表明：春玉米在灌浆初期经不同天数的低温处理后,穗粒数减少,穗粒重、百粒重和叶绿素降低,成熟期延迟,果穗秃尖长度和籽粒含水量增加,作物产量呈不同程度的下降。温度越低,持续时间越长,对玉米产量的影响越严重。其中在15℃低温下处理7天后,玉米产量下降最大,较对照穗粒重减少了32.4%,百粒重减少9.2%。可见,灌浆初期低温对春玉米产量结构影响最大的因素是结实率和籽粒干物质含量的双重降低。     

近年我国玉米超高产田的分布、产量构成及关键技术

2006—2010年,全国玉米栽培学组专家在全国不同区域开展了玉米高产潜力探索及小面积超高产创建工作。本文对经过严格测产且产量达到和超过15 000 kg hm^-2的159个地块的地理分布、产量构成因素及关键技术分析表明：(1)大多数高产田分布在较高纬度(40°~43°N)、较高海拔(1 000~1 500 m)地区,这些地区具有昼夜温差大、光照充足等利于高产的自然因素,选择这样的区域是实现超高产的重要因素; (2)平均单产16 692 kg hm^-2 ,88 950穗 hm^-2、每穗541粒,千粒重360.0 g,穗粒重191.8 g; 通径分析表明,穗数和粒数对产量的贡献最大; (3)高产关键技术主要是,采用耐密型高产稳产品种,合理提高密度,充足的水肥供给,科学管理和地膜覆盖等。     

绵麦系列小麦品种（系）的农艺性状和品质性状分析

为利用好小麦资源材料,对19份绵麦系列小麦品种（系）的农艺性状和品质性状等15个性状进行分析。结果表明,农艺性状与品质性状间有着复杂的相关关系,有13对性状表现为显著或极显著相关,有23对性状表现为显著或极显著偏相关。产量与8个农艺性状的关联系数的序次为：基本苗>千粒重>穗粒数>容重>株高>最高苗>生育期>有效穗;产量与6个品质性状的关联系数的序次为：稳定时间>最大阻力>籽粒蛋白>面积>吸水率>湿面筋;蛋白质与9个农艺性状的关联系数的序次为：最高苗>有效穗>基本苗>穗粒数>产量>容重>千粒重>株高>生育期;稳定时间与9个农艺性状的关联系数的序次为：容重>最高苗>产量>生育期>有效穗>千粒重>株高>基本苗>穗粒数;面积与9个农艺性状的关联系数的序次为：基本苗>穗粒数>千粒重>产量>株高>最高苗>有效穗>生育期>容重。供试材料从农艺性状和品质性状可被聚为三类,第Ⅰ_2、Ⅰ_3、Ⅰ₄类育种时可以作为高产材料加以应用,同时Ⅰ₃和Ⅰ₄类群育种时可以作矮杆材料加以运用;Ⅰ₁和Ⅰ₄类群育种时可以作为优质品质材料加以运用。第Ⅱ类育种时可从粒重方面加以应用;第Ⅲ类从优质矮杆材料加以应用。     

小麦抗倒性影响因子和产量因子的遗传与相关研究

旨在为小麦育种和生产上预防倒伏、提高稳产能力提供参考.以来源于野生二粒小麦远缘杂交组合的82个高代系为试材,在西北农林科技大学试验站测定并分析抗倒性影响因子和产量性状的相关性.结果表明,(1)株高与抗倒性呈负相关关系,成熟期茎壁厚与抗倒性呈正相关关系,各个性状的抗倒性排序为株高＞成熟期茎壁厚度＞单穗重＞单株重;(2)粒...     

小麦冠层结构与产量及其构成因素的典范相关分析

选用２０个小麦品种（系）,采用典范相关分析方法,分析了小麦冠层结构与产量及其构成因素的相关性。结果表明,产量与其构成因素和植株特性呈显著相关,穗粒数和穗数对产量和单株产量的贡献均较大,干物重和株高对产量的贡献最大;叶长与产量呈显著相关,倒三叶长对产量的影响最大,对单株产量的影响３片叶相近;茎壁厚、节间长与单株产量呈显著相关。产量构成因素与各冠层结构特性均存在显著的典范相关。茎壁厚和节间长与茎粗均相关显著;在叶片特性中,除叶宽与披垂度相关不显著外,其余各组性状间均相关显著。     

陕西省不同年代玉米品种产量和氮效率性状的变化

明确陕西省不同年代玉米产量和氮效率性状响应氮肥的变化趋势,对西北旱区玉米高产氮高效品种选育具有重要的实践意义。本文以1981—2010年间陕西省12个玉米主栽品种为材料,于2011年和2012年在典型旱区陕西长武进行3个氮水平(0、120和240 kg hm–2)的田间试验,分析了不同年代玉米品种农艺和氮效率性状变化趋势。结果显示,不同年代玉米品种籽粒产量随氮水平增加而提高,在施氮0、120和240 kg hm–2处理下籽粒产量增益分别为每年46、65和83 kg hm–2。所有氮水平下2000—2010年间品种产量和生物量显著高于1980—1989年间品种,而秸秆产量变化不明显;现代玉米品种(2000—2010年)产量的增加归因于穗粒数、千粒重和生物量的提高。不同年代玉米品种消光系数随氮水平增加而降低,说明现代玉米品种(2000—2010年)较老品种(1980—1989年)叶片直立,截获更多的光能,致使产量和生物量高。随着年代的递进,玉米品种氮肥农学利用率呈递增趋势,在低氮水平下现代品种氮肥利用效率最高,且显著高于老品种。氮肥农学利用率与氮吸收效率(NUpE)和花后氮素积累量呈显著相关(r=0.75;r=0.72),而与氮生理效率(NUtE)和花前氮素积累量相关性不显著(r=0.42;r=0.39)。说明现代玉米品种氮肥农学利用率提高主要来自氮肥吸收效率和花后氮素积累量的增加。上述结果表明,陕西玉米育种应注重穗粒数、千粒重、氮吸收效率性状和株型结构改良,低氮环境压力选择将有助于旱区玉米高产氮高效新品种培育。     

Veränderte Ährenfertilität bei einhalmiger Sommergerste durch Einsatz von Bioregulatoren

Changes in fertility of ears in monoculm summer barley after application of plant growth regulators
The effect of plant growth regulators (PGR) upon the structure of the ears in the monoculm summer barley Kindred Uniculm was tested during four years in pot experiments.
The influence of CCC + Ancymidol and RSW on yield structure of the whole plant and the ear which was divided in three parts (basal = 1.–5. spike internode, medial = 6.–10. spike internode, apical = off 11. spike internode) was measured. The application of PGR's in EC 32 increased kernel yield every year in a range from 11–21 %. Number of kernels were strongly improved while the thousand kernels weight remained unchanged. The increase in number of kernels in the apical zone was higher (26–64 %) than in the basal zone (0–10 %). Obviously "medial dominance" was reduced as the single kernel weight was the same in untreated plants.
The decrease of GA₁-content was evident after application of PGR's. A correlation between GA₁-content and plant height was found.     

基于控制授粉技术的玉米弱势粒发育与库特征的关系

明确弱势粒败育和灌浆受限与其库容量或库活性关系,对于探讨弱势粒调控途径、实现密植群体产量挖潜具有重要意义。本研究以典型玉米杂交种郑单958和先玉335为材料,在控制授粉条件下(不完全授粉IcP、完全授粉CP),比较成功发育弱势粒(IcP处理)和发育不良弱势粒(CP处理)的库容量和库活性及籽粒灌浆参数的差异。结果表明,不同控制授粉处理下,玉米弱势粒胚乳细胞增殖过程和最大胚乳细胞数无显著差异;IcP处理弱势粒可溶性酸性蔗糖转化酶(SAI)活性显著高于CP处理,平均差异和最大差异分别达12.6%和21.8%,且实测百粒重、籽粒终极生长量、最大灌浆速率和平均灌浆速率皆表现为IcP处理高于CP处理。可见,玉米果穗顶部弱势粒败育或灌浆停滞不受其库容量的限制,籽粒形成期的库活性是弱势粒败育或灌浆受限的核心限制因子。     

玉米“黄金”群体产量等性状轮回选择改良效果评价研究

利用群体改良方法,充分挖掘地方优异种质的遗传潜力是玉米种质改良与创新的一个重要途径。本研究以黄金群5个轮次改良群体为材料,通过1年2点产量比较试验,分析了混合选择和相互半姊妹轮回选择方法对黄金群产量及穗部性状的改良效果。结果表明,两种选择方法对群体产量改良是有效的,随着改良轮次的增加,黄金群的单株产量逐轮提高,平均每轮提高3.78%,其中,混合选择改良的3轮群体平均每轮提高4.27%,相互半姊妹轮回选择的改良群体提高2.07%;虽然群体产量的变异系数从15.43%下降到12.80%,但群体内仍有较丰富的变异。通过改良群体穗部性状比较发现,穗长和行粒数改良效果显著,分别提高14.71%和17.62%,说明它们的提高是群体单株产量提高的主要因素。     

中综3号玉米群体格子混合选择效果分析

用格子混合选择法完成了对中综3号玉米群体6轮混合选择, 并用5个测验种对C0、 C2、 C4和C6进行NCⅡ交配。 经过1995、 1996年对测交后代的2年3点鉴定, 结果表明： 中综3号与5个测验种的测交组合产量均逐轮提高。 经6轮选择后, 群体籽粒产量每公顷增加了1155(24.05%) kg, 平均每轮增加192(4.01%)kg。 产量的一般配合力从C0