氮肥基追比对花后高温胁迫下春小麦淀粉形成的影响

采用盆栽的方法研究不同的氮肥基追比对高温胁迫春小麦花后淀粉形成和产量的影响。结果表明:高温胁迫条件下,宁春4号和宁春47号籽粒直链淀粉、支链淀粉以及淀粉总含量、淀粉形成关键酶(ADPG-PPase、UDPG-PPase、SSS、GBSS)活性、千粒重和生物产量等与常温处理相比显著降低。两个品种氮肥基追比3∶7和4∶6条件下的直链淀粉含量、AGPP-PPase、GBSS、千粒重、生物产量等均优于氮肥基追比5∶5、7∶3、6∶4的处理。因此,花后高温降低了籽粒淀粉的含量、关键酶活性,从而降低了小麦产量和品质,而合理的氮肥基追比(3∶7和4∶6)能减轻高温对春小麦产量以及淀粉品质的影响。生产上可以采取相应的措施缓解高温的危害,提高春小麦产量和品质。     

河南省小麦黑胚病菌的分离鉴定及致病性测定

 为明确我国小麦主产区河南省小麦黑胚病菌的主要类群,为该病的防治工作提供理论依据,对河南省不同地区种植的50个小麦品种(系)的黑胚籽粒进行了分离鉴定和致病型测定。鉴定结果表明：河南省小麦黑胚籽粒病原分离物包括链格孢(Alternaria alternate)、麦根腐蠕孢（Bipolaris sorokiniana）、细极链格孢(A. tenuissima)和小麦链格孢（A. triticina）,平均分离频率分别为63.0%、18.0%、12.2%和6.8%,不同品种小麦黑胚籽粒各种病原菌分离频率有一定差异。扬花后10 d利用孢子悬浮液接种进行分离物的致病性测定,结果表明链格孢(A.alternate)和麦根腐蠕孢（B. sorokiniana）致病力较强。结合分离频率和致病性测定结果,确定链格孢(A. alternate)是河南省小麦黑胚病的优势病原菌。     

氮肥对不同HMW-GS组成类型品种春小麦主要品质指标的影响

以18个具有不同HMW-GS组成类型的春小麦为材料,在同一氮素水平条件下研究不同形态氮肥对春小麦籽粒蛋白质含量、干面筋与湿面筋含量和SDS沉降值4项品质指标的调节效应.结果表明,各项品质指标适宜的氮肥形态具有一定差异.氮肥形态和HMW-GS组成类型对籽粒蛋白质含量、干面筋与湿面筋含量的影响较小,而对SDS沉降值影响较为明显,但更主要受品种(品系)自身遗传特性的影响.     

东北春小麦根腐病防治研究

东北春小麦根腐病Bipolaris sorokiniana(Sacc.ex Sorokin)shoem.是推广抗锈良种后出现的问题。苗期引起根腐,成株期发生叶斑、穗腐和黑胚粒。病菌有两种类型定名为H_1和H_2型,田间前者占优势。病种子和病株残体是田间发病的初侵染源,种子消毒和轮作可减轻苗期根腐并提高种子出苗率。根腐病菌寄主范围很广,来自29种禾本科杂草和作物上的菌株均能侵染小麦。温室和田间试验结果,小麦灌浆乳熟期发病对产量影响最大,也是形成黑胚粒时期。目前尚无免疫品种,农家种和半冬性品种比国外品种和硬粒小麦抗病,Triticum timopheevii表现高抗。采取种植抗病品种结合种子消毒、轮作、增施氮肥等综合防治技术是防治小麦根腐病的有效措施。     

赤霉病对小麦籽粒产量和品质的负效应分析

通过调查比较黄淮麦区15个主栽小麦品种感染赤霉病后产量结构和籽粒品质的变化趋势,发现赤霉病对小麦产量结构具有一定的负效应。感染赤霉病后,各品种的千粒重、穗粒数及单穗产量均显著下降,受影响程度由重到轻依次为单穗产量>千粒重>穗粒数。赤霉病对西农529、航麦302和轮选158单穗产量的影响较大,对偃高168和连麦10号单穗产量的影响较小。各品种染病穗的籽粒加工品质下降明显。筛选出对赤霉病敏感度相对较低、发生赤霉病后籽粒减产及品质下降相对较少的5个品种：偃高168、山农12、保麦2号、航麦302、连麦10号。     

小麦对黑胚病的抗性及黑胚对产量损失的影响

人工接种试验结果表明,在相同时间、地点、栽培技术和接种条件下,１６０份小麦品种（系）感染黑胚病的程度有差异。其中２５份抗病,１３５份感病,病粒率在０１％～５７６％之间。接种区籽粒和自然感病区相比,６０％品种（系）千粒重增加,４０％品种（系）千粒重降低,且千粒重增减与其病粒率高低无关。黑胚病影响小麦产量的主要原因是穗粒减少,千粒重降低。     

小麦对黑胚病的抗性及黑胚对产量损失的影响

人工接种试验结果表明,在相同时间、地点、栽培技术和接种条件下,１６０份小麦品种（系）感染黑胚病的程度有差异。其中２５份抗病,１３５份感病,病粒率在０.１％～５７.６％之间。接种区籽粒和自然感病区相比,６０％品种（系）千粒重增加,４０％品种（系）千粒重降低,且千粒重增减与其病粒率高低无关。黑胚病影响小麦产量的主要原因是穗粒减少,千粒重降低。     

15%敌力脱乳油防治小麦黑胚病效果显著

近年来 ,小麦黑胚病在我国主要麦区发生严重 ,造成小麦籽粒黑胚 ,严重影响小麦品质 ,并降低出苗率。为防治小麦黑胚病 ,我们在小麦生长中、后期 ,对当地两个主栽小麦品种 4 5 89和 5 316进行了不同药剂防治试验。供试药剂有 2 5 %敌力脱乳油 (ｐｒｏｐｉｃｏｎａｚｏｌ)33ｍｌ/667ｍ2 ,瑞士诺华公司生产 ;15 %粉锈宁可湿性粉剂 70 ｇ/667ｍ2 ,江苏桥头农药厂生产 ;70 %代森锰锌可湿性粉剂 80 0倍液 ,江苏利民化工有限公司生产 ;70 %甲基托布津可湿性粉剂 70ｇ/667ｍ2 ,日本曹达株式会社生产 ;5 0 %多菌灵可湿性粉剂10 0 ｇ/667ｍ2 ,江苏吴县…     

优化施肥对春小麦产量、氮素利用及氮平衡的影响

2009 ～ 2010年,在宁夏引黄灌区分别以宁春11号和宁春16号小麦为供试作物,利用田间试验研究了优化施肥(OPT)和习惯施肥(CON)对春小麦产量、氮素吸收利用和土壤硝态氮累积的影响,表观评估了土壤—小麦体系氮素平衡.结果表明,相对于CK处理,OPT和CON都显著提高春小麦籽粒产量地上部生物量,并促进籽粒N和地上...     

干旱逆境下药剂处理小麦种子对灌浆期某些生理影响与产量形成的关系

在自然干旱条件下，进行田间小区试验，用1％CaCl2,50 μg/mlGA及其1：1的Ca GA混合剂处理小麦种子，观察对后期生长（灌浆期）某些生理变化与籽粒产量的关系。结果表明，药剂处理对灌浆期叶片含水量、叶绿素含量、光合作用参数、籽粒干物质积累都有不同程度的效应，其中以Ca^2 处理的效果最佳，这些结果与考种参数综合分析是一致的，其原因是籽粒产量不仅受生长后期一些生理活动的影响，也受生长初期的影响，而经Ca GA处理后成苗率高，成穗株数较多，对环境条件变化表现出较强的适应能力。     

半干旱区春小麦水分与产量关系及其影响因素分析

水分是影响半干旱雨养作物生长、发育及产量形成最重要的环境因素。以中国西北半干旱区田间试验为基础，收集长期观测资料和文献数据，分析春小麦产量与水分之间的关系及其环境影响因素，揭示不同环境条件下春小麦水分限制特征和调控机制。研究表明：半干旱区常规管理水平下，雨养春小麦产量与水分间的关系相对稳定，然而播前土壤储水影响生育期降水与春小麦产量间的关系，不同播前土壤储水条件下，每增加1 mm降水量，春小麦产量的增加量分别为21.3 kg·hm^-2和16.8 kg·hm^-2。生育期大气干湿条件（潜在蒸发量与降水的差值）对播前土壤储水与春小麦产量间的关系也有影响，其中大气较为干燥时（潜在蒸发量与降水的差值大于425 mm），产量与土壤水分间关系斜率为22.9 kg·hm^-2·mm^-1，大气较为湿润时（潜在蒸发量与降水的差值小于425 mm），斜率为20.1 kg·hm^-2·mm^-1。相较生育期降水，播前土壤储水对春小麦产量更具有决定性作用。半干旱雨养春小麦的气候年型由播前土壤储水和生育期大气干湿条件共同决定。增加播前土壤水分储量、在生育期的特定阶段灌溉均会改变小麦耗水量与产量之间的关系，并最终导致小麦水分利用效率发生变化。大气干湿条件和灌溉条件共同导致中国西北不同地区春小麦边界函数存在差异。     

Quality versus quantity: spring wheat seed size and seeding rate effects on Avena fatua interference, economic returns and economic thresholds

A 3-year field experiment was conducted at Kalispell, Montana, USA, to investigate the effects of spring wheat seed size and seeding rate on wheat yield loss (YL), economic returns and economic thresholds (ETs), as a function of Avena fatua density. Crop competitive ability increased as wheat seeding rate and seed size increased, with the greatest differences among treatment factors being observed at low weed densities. Both treatment factors decreased spring wheat YL, increasing economic returns during all 3 years of the study despite the higher associated seed costs. Averaged over all other factors, adjusted gross returns (AGR) were 477 and 537$ ha⁻¹ for the low and high seeding rates, while values of 453, 521 and 547$ ha⁻¹ were obtained for the small, bulk and large seed size classes respectively. Weed-free yield potential varied yearly. As yield potential increased, A. fatua competitive effects were more evident and ETs decreased. Nonetheless, both treatment factors increased ETs in 2 of 3 years. These results demonstrate that the use of higher seeding rates and larger seed size classes both improve wheat competitive ability towards A. fatua while simultaneously increasing economic returns.     

Growth of seedlings of Agropyron repens L. Beauv. and Agrostis gigantea Roth. in wheat and barley: effect of time of emergence, nitrogen supply and cereal seed rate

As part of a programme of work evaluating the role of seeds in regenerating or initiating infestations of Agropyron repens and Agrostis gigantea, the growth of the weeds was analysed in cereal crops in two experiments. The first experiment investigated the effects of time of planting the weed seedlings (simulating different times of emergence), nitrogen supply and cereal seed rate in winter wheat and the second, the same factors in spring wheat and spring barley. In winter wheat, delaying planting of the weeds from autumn until spring greatly decreased shoot growth and almost completely prevented rhizome formation. Nitrogen fertilizer increased the weight of shoots of both species planted at both times but whereas it increased the amount of rhizome produced by Agropyron it decreased that of Agrostis. Without nitrogen Agrostis had twice as much rhizome as Agropyron but with nitrogen Agropyron had twice as much as Agrostis. Decreasing the cereal seed rate had little effect on rhizome weight when nitrogen was not given but it allowed twice as much rhizome to be produced when it was supplied. However, more longer rhizomes were formed at the smaller than at the larger seed rate with both amounts of nitrogen. In spring cereals, late planting decreased the shoot growth of Agrostis more than that of Agropyron, and of Agropyron in barley more than in wheat, especially at the smaller seed rate. Nitrogen increased shoot weight of Agropyron in wheat but had little effect in barley; it decreased that of Agrostis in barley. On average, rhizome growth was decreased by nitrogen, by increasing the seed rate and by delaying planting. Agropyron rhizomes were heavier in wheat than in barley but those of Agrostis were heavier in barley than in wheat. Agropyron produced most rhizome in thinlysown wheat given nitrogen, but Agrostis most in thinlysown barley without nitrogen. The two treatments had an equal number of rhizomes longer than 100 cm. The agricultural significance of the interaction of the various treatments is briefly discussed.     

Effects of grazing intensity on seed production of Caragana stenophylla along a climatic aridity gradient in the Inner Mongolia Steppe,China

As the increases of climatic aridity and grazing intensity,shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions,and its abundance also generally increases.However,the effects of climatic aridity and grazing intensity on sexual reproduction of shrubs in grassland remain largely unclear.In order to understand the effects of grazing intensity and climatic drought stress,and their interaction on seed production of shrub species,we examined the seed number,seed weight and seed yield of Caragana stenophylla under three grazing intensities(fenced,mild grazing and severe grazing) across a climatic aridity gradient(semi-arid,arid,very arid and intensively arid zones) in the Inner Mongolia Steppe,northern China during 2012–2013.The seed number,seed weight and seed yield gradually increased from the semi-arid to the very arid zones,but decreased from the very arid to the intensively arid zones in fenced plots.The seed number and seed yield decreased from the semi-arid to the intensively arid zones in mild and severe grazing treatment plots,therefore,grazing enhanced the suppression effect of climatic aridity on seed production of C.stenophylla.The seed number and seed yield gradually decreased as grazing intensity increased.The seed weight was highest in severe grazing plots,followed by the mild grazing plots and then the fenced plots.Precipitation varied interannually during the study period.We observed that the seed number,seed weight and seed yield were lower in the low precipitation year(2013) than in the high precipitation year(2012).As climatic drought stress increased,the negative effects of grazing on seed production of C.stenophylla also gradually increased.Our results indicated that climatic drought stress may contribute to the encroachment of C.stenophylla shrub in arid zones by promoting its seed production.However,grazing had negative effects on sexual reproduction of C.stenophylla,and the combined effects of drought stress and grazing seriously suppressed sexual reproduction of C.stenophylla in the intensively arid zone.     

Effects of deficit irrigation with saline water on spring wheat growth and yield in arid Northwest China

Field experiments were conducted in 2008 and 2009 to study the effects of deficit irrigation with saline water on spring wheat growth and yield in an arid region of Northwest China. Nine treatments included three salinity levels s1, s2 and s3 (0.65, 3.2, and 6.1 dS/m) in combination with three water levels w1, w2 and w3 (375, 300, and 225 mm). In 2008, for most treatments, deficit irrigation showed adverse effects on wheat growth; meanwhile, the effect of saline irrigation was not apparent. In 2009, growth parameters of w1 treatments were not always optimal under saline irrigation. At 3.2 and 6.1 dS/m in 2008, the highest yield was obtained by w1 treatments, however, in 2009, the weight of 1,000 grains and wheat yield both followed the order w2 > w1 > w3. In this study, spring wheat was sensitive to water deficit, especially at the booting to grain-filling stages, but was not significantly affected by saline irrigation and the combination of the two factors. The results demonstrated that 300-mm irrigation water with a salinity of less than 3.2 dS/m is suitable for wheat fields in the study area.     

氮磷水平与比例对不同品质类型春小麦磨粉品质的影响

以3个不同品质类型春小麦品种为材料,在田间施肥试验基础上探讨了不同氮磷水平与比例对春麦千粒重、容重及各项出粉率等磨粉品质性状的影响。结果表明,施肥处理间容重、心粉出粉率和总出粉率差异显著。氮磷水平与比例的提高,对各基因型千粒重的影响很小,却使容重显著降低,总出粉率普遍显著增加。各基因型心粉出粉率随氮肥增施显著降低,而随磷肥增施显著增加;皮粉出粉率随氮磷肥增施不同基因型呈现不同变化。千粒重、容重与各项出粉率受氮磷肥影响程度各基因型间呈现一定差异。强筋品种千粒重、容重更易受氮水平影响,而中筋与弱筋品种则更易受磷水平影响。在受氮磷肥增施影响程度方面,总出粉率和心粉出粉率均为强筋大于中筋品种;皮粉出粉率则是弱筋品种受影响较大。适当增施氮磷肥有利于提高春小麦磨粉品质。     

UV-B增强对中高海拔干旱半干旱地区春小麦植株形态的影响

以春小麦"宁春4号"为供试材料,采用大田定位试验,利用可升降式紫外灯装置,观测增加不同剂量UV-B情况下春小麦的株高、绿叶数及叶部形态的变化状况.连续两年的试验结果显示,UV-B增强使春小麦植株矮化、绿叶数减少、叶角变小、单叶叶面积减小.单叶叶面积减小的原因是叶长和叶宽都有所减少.多数情况下,随着UV-B辐射增加量越多,春小麦株高和叶形态受到的影响程度越大.在中高海拔干旱半干旱地区,UV-B增强使春小麦的株型缩小、绿叶教减少,这会对春小麦的于物质积累和籽粒形成产生不利影响.     

不同灌溉量对春小麦生长及产量构成的影响

在大田条件下,研究不同灌溉量对干旱半干旱地区春小麦生长及产量构成的影响,以期为春小麦节水灌溉提供理论依据.结果表明,灌溉量为4 286 m3/hm2(常规对照灌溉量4 495 m3/hm2,减少209 m3/hm2)未对春小麦生长及产量造成不利影响;灌溉量为3 6 70 m3/hm2(比常规灌溉量减少825 m3/hm2)对春小麦生长产生了部分不利影响,但没有使产量明显降低;灌溉量为3 060 m3/ hm2(比常规对照减少1 435 m3/hm2)使春小麦株高降低、干鲜重减少、产量明显减少,对春小麦生长及产量产生明显不利影响.综合考虑,正常年份宁夏引黄灌区春小麦适宜灌溉量在3 900～4 200 m3/hm2,尚有200～5 00 m3/hm2的节水潜力.     

柴达木地区春麦高产优质栽培因子优化组合研究

采用三因素二次通用旋转组合设计,在柴达木地区以春小麦甘春20号为对象研究了播种量、施氮量、施磷量与籽粒产量、蛋白质含量、蛋白质产量的相关关系。结果表明,该地区春小麦甘春20号的籽粒产量、蛋白质含量、籽粒蛋白质产量与播种量、施氮、磷量之间有极显著的相关关系。施氮量对籽粒产量、蛋白质含量、籽粒蛋白质产量影响最大,播种量次之、施磷量最小。该地区甘春20号小麦栽培因子最优组合为播种量404.5 kg/hm2、施氮量(纯氮)240 kg/hm2、施磷量(P2O5)195 kg/hm2。建议当地降低播种量,增加磷肥施用量。     

呼和浩特地区施磷对春小麦养分吸收和生物产量的影响

内蒙古农业大学教学农场大田设施磷与不施磷两处理，分析研究春小麦不同生育期体内的氮、磷、钾含量、吸收量，干物质积累量和生物产量。结果表明，乳熟一蜡熟阶段是春小麦养分吸收和生物产量积累的最快时期，磷可提高植株体内氮、磷养分浓度，对其他养分浓度影响不是很明显。磷素有利于干物质积累，可以增加春小麦生物产量和籽粒中氮、磷含量，但对钾素的影响不明显。因此，在制定施肥方案时，应重视氮、磷、钾的合理配合，以满足春小麦“高产、优质、高效”生产的营养需要。