夏玉米高产群体形态质量指标的研究

玉米品种掖单22不同群体密度的田间试验结果表明,群体密度(X)与产量(y)呈二次曲线关系,回归方程为y=127.53+406.16X-39.42X2;与单株粒数、穗重、百粒重呈显著负相关,相关系数分别为-0.988 9**、-0.9949**和-0.981 6**;穗位以上叶面积(X)与产量(y)呈直线关系,回归方程为y=154.44+0.308 6X,r=0.961 3**;节间长度与穗重、穗粒数、百粒重呈负相关,穗粗、重量与之呈正相关.每公顷产量13 500kg时,适宜群体密度为6.69万～8.75万株/hm2,单株穗位以上叶面积为3 406.2～4 765.7 cm2,单株地上根条数达到35～46条.     

生态因素对玉米子粒发育影响及调控的研究

通过播期、覆膜调控，研究了不同生态条件下不同类型品种的生长发育，重点研究生态因素对玉米花后子粒发育的影响。试验主要结果如下：高温少光条件影响子粒灌浆，表现在灌浆期持续时间短、灌浆速率相对较低。晚熟品种灌浆期长而灌浆速率相对较低，早熟品种灌浆期短而灌浆速率相对较高，是正常年份两类品种都能取得高产的原因。子粒体积变化与干重变化趋势一致。适宜生态条件下，玉米穗粒性状变异系数小，果穗发育整齐一致。掖单13穗长较大，易于形成大果穗，高产潜力大，但高温少光条件下，穗粒性状变异系数大，果穗不整齐，产量低。高温少光条件下，子粒呼吸速率明显降低，高值持续时间短；同时CTK含量较低。ABA含量变化规律性不强，子粒生长受多种内源物质协调调控。     

株行配置对春玉米根冠空间分布及产量的影响

以先玉335为试验材料,设置7.50万株/hm2和9.75万株/hm2两个种植密度,60 cm+60 cm等行距和40 cm+80 cm宽窄行两个行距配置,比较株行配置对春玉米冠层、根系结构与功能及产量的影响。结果表明,随种植密度增加,果穗、茎鞘干重百分比垂直分布明显上移,叶片干重百分比在垂直分布变化较小,行距配置对果穗、茎鞘干重百分比在垂直分布上影响较小。相对于等行距种植,宽窄行种植叶片干重百分比有下移趋势,群体不同叶位叶面积指数也表现为同一密度下,宽窄行种植群体上层LAI较小,穗位叶高效叶层LAI较大;随密度增加,根重有纵向下移的趋势,根系TTC还原强度在不同土层深度都显著降低。同一密度下,宽窄行种植根重的垂直分布出现下移趋势,根系TTC还原强度略高于等行距种植。高密度条件下,宽窄行种植降低了玉米果穗秃尖长,显著增加果穗穗粒数,因而显著提高产量,增产2.73%~10.86%,说明在宁夏扬黄灌区较高种植密度下,采用宽窄行种植能优化不同叶层结构,适当增加深层土壤根系所占比例及活力,有利于获得高产。     

玉米新品种振杰5号单粒播种栽培技术

振杰5号是聊城市华丰玉米育种研究所选育的高产、稳产、广适、多抗型、最新审定的杂交玉米新品种。该品种株型紧凑,植株长势稳健,叶色浓绿,根系发达,抗倒伏,结实性好,无秃顶,活秆成熟,不早衰。夏播生育期96d,株高260cm,穗位95cm,果穗筒型,穗行数平均16.4行,穗粒数平均542粒,白轴,出子率88.0%,千粒重344g,容重712g/L。是适应单粒播种创高产的玉米新品种。     

不同密度下施氮对甜玉米果穗形成的影响

以甜玉米甜单8号为材料,在不同种植密度(45 000、60 000和75 000株/hm²)及不同供氮水平(0、120和240 kg/hm²)下对果穗产量、穗粒结构、穗部性状形成过程及子粒灌浆动态进行了研究。结果表明：施氮水平、种植密度对甜玉米产量影响显著,施氮可显著提高鲜穗产量与子粒产量;穗长、穗粗的形成贯穿整个果穗发育过程,可用Logistic曲线拟合,分别在吐丝与抽雄期达到最终穗长与穗粗的50%;穗粒数在抽雄期达到最高峰,随时间推进果穗败育粒增加;施氮对单穗重的提高在高密度下最明显。施氮能够促进玉米子粒的灌浆,但不同密度下施氮对灌浆动态的影响明显不同,在4～20 DAP子粒体积、百粒鲜重、灌浆速率均明显升高,且施氮处理高于不施氮处理。     

中国杂交水稻在柬埔寨的生长发育与产量表现

为了解中国杂交水稻在柬埔寨的生长表现和生产应用价值,2016年在柬埔寨王国菩萨省巴干县试种了13个中国杂交水稻品种,系统观察了其生长发育与产量表现。结果表明,这13个品种在柬埔寨试种地均可正常生长,全生育期86~98 d,主茎总叶片数14~15叶。在充分满足生长期水肥协调供应的情况下,24 cm行距、10 cm株距、单株移栽,最终株高80~105 cm、伸长节间数5个左右、茎蘖成穗率51%~76%、单株成穗数6.9~9.9个,主穗长22~30cm、每穗总粒数161~253粒、每穗实粒数154~238粒,结实率90%左右;不同品种的千粒重在19.7~30.1 g之间,单穗实粒质量2.37~4.59 g,单株产量21.8~37.7 g,小区实收稻谷折合产量6.8~10.5 t/hm2。     

移栽密度对北方稻鸭种养模式不同类型粳稻产量及生理特性的影响

采用裂区设计,在稻鸭种养有机栽培模式下研究了移栽密度对穗粒兼顾型品种沈稻47和穗数型品种沈稻505产量及生理特性的影响。结果表明,随着移栽密度增加,2个品种的叶面积指数（LAI）和单位面积有效穗数均增加;沈稻47齐穗前干物质积累所占比例、干物质总积累量和产量明显增加,每穗颖花数、结实率明显减少;沈稻505每穗颖花数明显减少,结实率、群体干物质积累量和产量先增后降;品种和密度在产量等多个性状上互作效应显著;穗粒兼顾型品种沈稻47取得高产的适宜移栽密度为30.0 cm×9.9 cm（33.0万丛/hm²）,穗数型品种沈稻505为30.0 cm×16.7 cm（20.0万丛/hm²）。     

西藏林芝地区玉米地膜与露地栽培主要性状研究

玉米地膜覆盖、露地栽培两种种植方式的生长发育特点、植株形态及产量性状是完全不同的。应用灰色关联方法分析结果表明:两种种植方式都表现为果穗粒重对产量影响最大。地膜玉米的穗位高度、果穗重、单株绿叶面积对产量有较大影响;露地玉米对产量有较大影响的性状是百粒重、果穗重和株高。模糊综合评判方法分析,地膜玉米应种植75000株/hm2,产量可达到6750～7500kg/hm2,果穗粒重必须保持88.9g,穗位高78cm,单果穗重170g,生育后期叶面积指数为2。而露地玉米产量在3750～4500kg/hm2,果穗粒重是60g以上,百粒重30～31g,单果穗重80～90g,植株高度应达到105cm,在西藏林芝及气候相似地区种中熟玉米应采用地膜覆盖栽培。     

野燕麦对不同小麦品种产量性状的影响及其经济阈值

为给防除小麦田间恶性杂草野燕麦提供依据,采用添加系列试验和模型拟合的方法研究了野燕麦与小麦的竞争.结果表明,随着田间野燕麦密度的增加,小麦有效穗数、穗粒数和产量逐渐降低,而小麦千粒重的变化趋势不明显.模型拟合结果显示,野燕麦密度与小麦有效穗数和产量间的关系以指数模型(y=beax)较好,与穗粒数间的关系以直线模型(y=ax b)较好,而与小麦产量损失间的关系以对数模型(y=alnx b)最佳.野燕麦对矮秆小麦品种郑麦9023产量性状的影响大于对高秆品种鄂麦35057的影响.根据小麦的经济危害允许水平,通过拟合的野燕麦密度与小麦产量损失的对数模型估算,当小麦品种为鄂麦35057时,野燕麦人工防除的经济阈值为9.04株·m-2,使用6.9%精噁唑禾草灵水乳剂化学防除的经济阈值为3.77株·m-2;而当小麦品种为郑麦9023时,相应的经济阈值分别为5.85株·m-2和3.32株·m-2.不同小麦品种的生长竞争能力存在较大差异,这可能是导致野燕麦与小麦间的竞争发生变化的原因.     

稀施保混配对大麦后期生长的影响

稀施保俗称玉米健壮素,通过对大麦后期生长的影响试验研究。结果表明,稀施保与各肥料农药混配不影响其对植株的调控作用,在大麦叶龄余数1.5叶,使用一次,可降低株高2.2 cm;穗下节缩短3.5 cm;每穗粒数减少0.2粒;千粒重增加1.0 g。稀施保在大麦叶龄余数1.5叶和叶龄余数0.5叶两次使用,可降低株高6.6 cm;穗下节缩短4.8 cm;每穗粒数减少0.5粒;粒重降低0.8 g。     

Is barley yield in the UK sink limited?: II. Factors affecting potential grain size

In the absence of serious post-anthesis stress, the potential supply of assimilates for grain filling in barley appears to exceed the storage (sink) capacity of the grains. The sink capacity is a function of the number of grains per unit land area and their potential size. In order to investigate the contribution of pre and early post-anthesis factors in the control of potential grain weight, regression analysis has been used to analyse data from field experiments conducted on winter barley crops cv. Pearl grown at six sites across the UK between 2002 and 2004. Crops were grown under a comparable husbandry regime with a full crop protection, growth regulator and fertilizer programme. The mean grain weight (MGW) varied from 35 to 46 mg at 100% dry matter over 17 site/year combinations. The variation in MGW between site/years was associated with differences in the rate rather than the duration of grain filling. MGW did not relate well to any measure of above ground growth or crop structure at ear emergence (Zadoks GS59). There was a significant positive linear relationship between MGW and the amount of radiation (PAR) intercepted per unit grain number between ear emergence and the start of rapid grain filling (r² = 0.32, P = 0.023), but not over the whole grain filling period. This is consistent with the view that MGW is determined by potential grain size. A multiple regression model comprising five explanatory variables accounted for a much larger proportion of the total variation in MGW (r² = 0.72, P = 0.013) than PAR interception on its own. There were significant positive associations of MGW with post-anthesis radiation use efficiency and PAR intercepted from GS59 to the start of rapid grain growth (RGG), and significant negative associations with the shoot number per plant, mean air temperature from GS39–59 and mean daily rainfall from GS59-RGG. The results suggest that both pre and post-anthesis conditions operate in concert to determine the potential grain weight of barley in temperate climates. The dry weight and water content of grains and ears followed a common pattern during grain growth for all site/years when the percentage moisture content was used as an index to normalise different rates of development. Use of the above data for predicting potential grain weight of barley prior to harvest is discussed.     

花后水分亏缺对夏玉米产量及水分利用效率的影响

以郑单958为试验材料,分别于吐丝至吐丝15 d、吐丝至吐丝30 d和吐丝30 d至成熟期3个时期进行水分亏缺处理(T1、T2、T3),以花后适宜水分供应为对照(CK),研究花后不同时期水分亏缺对夏玉米产量和水分利用效率的影响。结果表明,3个阶段的水分亏缺均使玉米产量降低,其中,T1处理的降幅最大,T3处理的降幅最小,与CK相比均达到显著性差异。T1处理下玉米的叶片衰老最快,在整个生育后期叶面积指数一直处于较低的水平;成熟期时,各处理的叶面积指数均低于CK。T1和T2处理使成熟期时的单株总干重显著下降,较CK分别下降了24.98%、29.94%。T3处理下作物的水分利用效率最高,比CK高0.5 kg/(mm·hm2);T1处理下作物的水分利用效率最低,且与CK达到显著差异。各个时期的水分胁迫均使玉米的穗粒数减少,穗长变短,穗粗降低,行粒数减少,秃尖变长,空秆率上升。     

TP爆裂玉米的品种特性

从泰国爆裂玉米TP中分离出30多个株系，对它们的生育期、穗部性状和爆裂品质进行了观察和测定。结果表明，绝大多数株系从出苗至抽雄期为68天左右，各株系表现出穗较长较粗、行数多、单株产量较高的特点，平均穗长、穗粗、穗行数、行粒数、百粒重、单株产量分别为15．9cm、3．4cm、15.7行、39粒、13．5g和71．3g。爆花率平均为886％，27％以上的株系高于95％。膨胀倍数平均为16．4倍。30％以上的株系在18倍以上。膨胀体积平均为21．3ml／g，13％的株系在250ml／g以上，穗部性状与爆裂品质之间只有微弱的相关，表明对TP群体进行进一步改良是有潜力的。     

糯玉米杂交育种研究

本文就糯玉米杂交育种中的几个问题进行了探讨,使用有限结实和无限结实两个概念对玉米的结实性进行了分类.作者认为:(1)有限结实习性对玉米的丰产、稳产和糯玉米的外观商品品质具有重要作用,(2)与株高穗位性状一样,果穗大小和子粒大小的一致性是体现各类玉米产量杂种优势的另一重要因素,(3)吐丝快、花期协调可保证玉米果穗上子粒间的授粉、发育基本同步,从而使同一果穗上子粒间的养分竞争趋于平衡,在发育好的果穗上表现为子粒大小基本一致,少有小粒、瘪粒存在,从而为玉米杂交种高产、稳产以及糯玉米杂交种果穗的外观商品品质提供保障。     

Effect of plant density on toxigenic fungal infection and mycotoxin contamination of maize kernels

Field experiments were set up from 2001 to 2004 in North West Italy to determine the effects of plant density on the susceptibility of medium and medium-late maturity maize hybrids to ear rot and to mycotoxin contamination in natural infection conditions. The ears were rated for the incidence and severity of disease symptoms at harvest and the harvested kernels were analysed for mycotoxin fumonisin B₁, zearalenone, deoxynivalenol, aflatoxin B₁ and ochratoxin A.     

籼粳杂交后代幼苗NH4＋吸收、同化的效率

 以籼稻广陆矮4号为母本与粳稻黄金光、笹锦为父本的杂交后代作试验材料。试验结果表明，籼粳杂交后代幼苗的生长大干它的亲本。杂交后代和它的亲本在NH4吸收速率上的差异为：母本（籼）>杂交后代>父本(粳)。杂交后代和母本在NH₄吸收速率上的差异小于和父本的差异．可能母本对杂交后代在NH₄吸收速率上的影响大于父本。NH₄吸收的Km杂交后代<父本<母本。Im是母本>杂交后代>父本，但母本与杂交后代之间的差异较小。杂交后代NH₄的吸收具有偏低的Km，偏高的Im，有较高的NH₄吸收效率。NH₄同化效率，杂交后代有杂种优势，比亲本高10%上下。     

玉米小面积超高产创建及配套栽培技术研究

2006～2007年全国出现39块玉米超高产田,绝大多数集中在北纬40°～43°的高海拔地区,其特点是光照充足和昼夜温差大。产量在15000kg/hm²以上高产田的产量结构是79725～84630穗/hm²,每穗560～588粒,千粒重347～359g,穗粒重200g左右。高产配套栽培技术是生态条件优越地区,采用良种,合理密植,科学施肥和及时灌溉。     

Effect of water stress at different development stages on vegetative and reproductive growth of corn

A field study was carried out from 1995 to 1997 in order to determine the effect of irrigation and water stress imposed at different development stages on vegetative growth, grain yield and other yield components of corn (Zea mays L.). The field trials were conducted on a silty loam Entisol soil, with Pioneer 3377 corn hybrid. A randomised complete block design with three replications was used. Four known growth stages of the plant were considered and a total of 16 (including rain fed) irrigation treatments were applied. The effect of irrigation or water stress at any stage of development on plant height, leaf area index, grain yield per hectare, as well number of ears per plant, grain yield per cob and 1000 kernels weight, were evaluated. Results of this 3-year study show that all vegetative and yield parameters were significantly affected by water shortage in the soil profile due to omitted irrigation during the sensitive tasselling and cob formation stages. Water stress occurring during vegetative and tasselling stages reduced plant height, as well as leaf area development. Short-duration water deficits during the rapid vegetative growth period caused 28–32% loss of final dry matter weight. Highest yields were observed in the fully irrigated control (VTCM) and the treatment which allowed water stress during the vegetative growth stage (TCM). Even a single irrigation omission during one of the sensitive growth stages, caused up to 40% grain yield losses during dry years such as 1996. Much greater losses of 66–93% could be expected as a result of prolonged water stress during tasselling and ear formation stages. Seasonal irrigation water amounts required for non-stressed production varied by year from 390 to 575 mm. Yield response factor (k_y) values (unitless parameter) relating yield loss to water deficits) obtained for the first, second and third experimental years were determined to be 1.22, 1.36 and 0.81, respectively.     

The effects of cultivar and prophylactic fungicide spray for leaf diseases on colonisation of maize ears by fumonisin producing Fusarium spp. and fumonisin synthesis in South Africa

Fumonisins are mycotoxins produced primarily by Fusarium verticillioides and Fusarium proliferatum on maize. These are secondary, carcinogenic metabolites and have been reported on maize worldwide. Field trials were conducted during 2010/2011 and 2011/2012 in six diverse maize production areas of South Africa to study the efficacy of an existing prophylactic fungicide regime for the control of foliar diseases, on the infection of grains of seven cultivars by fumonisin producing Fusarium spp. and fumonisin synthesis. Seven cultivars were selected to include both yellow and white, Bt and non-Bt and regionally adapted varieties. Azoxystrobin + difenoconazole (strobilurin, 200 g/L + triazole, 125 g/L) was applied 40–45 days after planting followed by flusilazole + carbendazim (silicone triazole, 125 g/L + benzimidazole, 250 g/L) with petroleum as adjuvant, 28–30 days later. Fumonisins in harvested kernels were analysed using High Performance Liquid Chromatography (HPLC) and fumonisin producing Fusarium spp. were quantified by means of quantitative Real Time PCR (qPCR). Mean natural colonisation of maize kernels by fumonisin producing Fusarium spp. was highest at Makhathini (33,696 pg/0.5 g of milled maize kernels) and the lowest at Potchefstroom (179 pg/0.5 g of milled maize kernels). Cultivars differed in susceptibility to fungal colonisation and fumonisin synthesis with PAN6P-110, DKC80-10 and CRN3505 proving most susceptible and LS8521B and DKC78-15B most resistant. Mean fumonisin contamination was highest at Makhathini (23.62 ppm) and lowest at Buffelsvlei (1.50 ppm). Analysis of variance showed no significant differences in colonisation of grain by fumonisin producing Fusarium spp. between sprayed and control treatments. Sprayed treatments had significantly higher fumonisin levels compared with unsprayed treatments. A highly significant cultivar × environment interaction was recorded for fungal colonisation. Highly significant environment × fungicide-treatment × cultivar interactions were recorded for fumonisin production. The strong interaction between cultivar and environment may be due to cultivar adaptation/behaviour under different environmental conditions. The use of a prophylactic fungicide spray regime for control of leaf diseases in maize did not reduce Fusarium ear rot in maize, however, significantly elevated fumonisin levels were recorded.     

不同粒重类型玉米品种耐密性的群体库源特征研究

利用作物生长分析法,研究了不同粒型玉米品种产量、产量构成和群体库源特征等指标与种植密度的关系。结果表明,种植密度为30000～60000株/hm²,鲁单981(LD981)的单位面积实收穗数是决定群体子粒产量的限制因素;高于60000株/hm²,穗粒数与千粒重则是决定群体子粒产量的限制因素。泉兴2101(QX2101)群体子粒产量的限制因素是单位面积实收穗数。LD981的单株产量、群体产量与产量构成因素对种植密度的敏感度要高于QX2101,前者在较低密度时,易获得较高的群体库源比值与群体叶面积指数,产量潜力较高;后者则在较高密度时,易获得较高的群体库源比值与群体叶面积指数,产量潜力较高。群体库容量与源供应能力均是两种粒重类型玉米品种产量的限制因素,但群体库容量始终占主导作用。