Relation between susceptibility to wheat bug attack and digestibility of glutenin

Two trials of winter wheat, embracing 17 varieties and 4 breeding lines, harvested in 2003 from locations in the semi-arid eastern part of Austria, were severely infested by naturally occurring bugs (Eurygaster sp.). In these trials bug damage was determined by selecting and weighing the infested kernels. Glutenin degradation was determined by the addition of meal from bug-infested kernels to meal from sound kernels from the same trials to reach sample mixtures representing a degree of bug attack of 6%. These mixtures and blanks made from sound meal were incubated in buffer solution (pH=8.5) at 37 °C for 45 min. The reduction in glutenin content due to the activity of bug proteinases was measured by RP-HPLC analysis of the glutenin fraction and comparison of the results of damaged and sound samples. The results showed good correlations between the degree of bug attack and the digestibility of glutenin (location 1: R²=0.69, P<0.01; location 2: R²=0.36, P<0.01). Both parameters seem to be variety specific. The determination of digestibility of glutenins was repeated in material from a trial harvested in 2005 in another location in eastern Austria, with eight varieties being the same as used in the 2003 trials. A correlation with the degree of bug attack in location 1 from the 2003 harvest was found again (R²=0.61, P<0.01).     

几种药剂对小麦黄矮病的防治效果

为明确病毒抑制剂对小麦黄矮病的预防和防治效果,在小麦起身期将大麦黄矮病毒GAV株系接种于小麦陕恳9740上,喷施杀虫剂(2.5%吡虫啉可湿性粉剂2000倍液)与病毒抑制剂(20%病毒A可湿性粉剂500倍液、3.95%病毒必克可湿性粉剂500倍液、5%菌毒清水剂500倍液和2%菌克毒克水剂300倍液)的不同组合,于小麦开花期统计发病率、病情指数和小麦叶片黄化率,结果表明,各组合均能早期预防和防治小麦黄矮病发生和发展,且预防效果优于防治效果,其中病毒必克与吡虫啉组合的平均预防和防治效果最显著,分别为58.08%和53.03%.进一步利用病毒必克在室内进行防治性试验,发现病毒必克能够抑制GAV对叶绿素的破坏,可减轻大麦黄矮病毒对小麦的危害.     

Identifying traits to improve the nitrogen economy of wheat: Recent advances and future prospects

Nitrogen fertilizer represents a significant cost of production for the grower and may also have environmental impacts through nitrate leaching, use of fossil fuels for manufacture and application, and N₂O emissions associated with denitrification. The development of N-efficient cultivars will be of economic benefit to farmers and will help to reduce environmental contamination associated with excessive inputs of N fertilizers. The physiological, metabolic and physio-chemico processes that may contribute to high N-use efficiency (NUE) and reduced N fertilizer inputs while maintaining an acceptable yield are reviewed and the prospects for application in breeding programs discussed. Promising N management strategies for high NUE are also considered. Traits operating from the cellular to the whole-crop scale, including root traits, nitrate assimilation, N partitioning, leaf and canopy photosynthesis, senescence, grain N remobilization and grain protein content and composition, are discussed in relation to their optimization in both feed and bread-making cultivars. Promising traits for selection by breeders to increase NUE are identified, and approaches for their integration at the whole plant level discussed. It is concluded that: (i) increased root length density (RLD) at depth, (ii) a high capacity for N accumulation in the stem, potentially associated with a high maximum N-uptake rate, (iii) low leaf lamina N concentration, (iv) more efficient post-anthesis remobilization of N from stems to grain, but less efficient remobilization of N from leaves to grain, both potentially associated with delayed senescence, and (v) a reduced grain N concentration may be of particular value for increasing NUE in feed wheat cultivars; and (vi) for bread-making cultivars, high NUE may be associated with high capacities for uptake and assimilation of N, with high post-anthesis N remobilization efficiency and/or specific grain protein composition.     

Proteolytic extraction enhances specific detection of the novel ‘S’-type low molecular weight glutenin subunit in wheat by monoclonal antibody

Specificity of monoclonal antibodies (MAbs) is required in diagnostic immunoassays. However, structural homology between a target antigen and other cellular proteins often causes promiscuous cross-reactivity of a MAb to proteins other than its target antigen, thereby hindering specificity. It is proposed in this study that specific proteolytic enzymes could be useful in the reduction or elimination of cross-reactive epitopes while retaining target epitopes for certain MAbs. The hypothesis was tested using a novel ‘S’-type low molecular weight glutenin subunit (LMW-GS-‘S’) and its antibodies. The results demonstrated that the protease, chymotrypsin, markedly reduced the cross-reactivity in samples that would otherwise obscure the specific detection of LMW-GS-‘S’ by MAb F8-14E6 in an enzyme-linked immunosorbent assay (ELISA). Further investigations revealed that the working mechanism for this proteolytic treatment was indeed due to the selective cleavage that destroyed cross-reactive epitopes whilst retaining the intact specific epitope. As more proteases are being discovered or engineered, the successful utilization of protease in immunoassays as reported here will benefit general immunodiagnostic assay development in both medicine and agriculture by targeting specific epitopes with tailored proteolytic treatment of antigens.     

植物生长调节剂拌种对扬麦13茎秆生长及籽粒产量的影响

为给高产小麦合理选用生长调节剂提供科学依据,以弱筋小麦扬麦13为试验材料,研究了不同生长调节剂(矮壮素、拌种剂、种衣剂、多效唑)拌种对不同群体小麦茎秆生长及籽粒产量的调节效应。结果表明,拌种处理均能有效降低扬麦13的株高、重心高度及基部节间长度,对茎秆粗度、茎壁厚度、茎秆干重的调节效应因生长调节剂种类不同而存在差异,其中,低密度条件下拌种剂处理的小麦茎壁厚度增加显著,而高密度条件下多效唑处理小麦的茎壁厚度增加显著。生长调节剂拌种处理提高了扬麦13的抗倒伏能力,其作用效果表现为多效唑种衣剂拌种剂矮壮素。相关分析表明,降低植株株高、基部第一节间长度,增加基部第一、二节间壁厚有利于提高植株抗倒性能。拌种处理下小麦产量均高于对照,300×104株·hm-2群体的产量高于150×104株·hm-2群体,均以种衣剂拌种处理增产最明显,平均增幅达11.68%,在倒伏年拌种处理增产效果更显著。     

小麦株高及其构成因素的遗传及相关性分析

为了给小麦抗倒伏育种提供依据,以7个株高差异较大的冬小麦品种为亲本,按Griffing双列杂交法Ⅱ配制21个杂交组合,研究了小麦株高及其构成因素的遗传和相关性。结果表明,株高及其构成因素的遗传均符合加性显性模型,以加性效应为主,显性程度为部分显性,遗传力高,早代选择有效。控制株高、穗长、倒一、倒二、倒三、倒四节间长的增效等位基因为显性,而控制倒五节间长的减效等位基因为显性。宁麦8号、宁麦9号、扬麦9号和扬麦11具有控制株高、倒一、倒二、倒三和倒四节间长较多的隐性基因;望水白具有控制穗长最多的显性基因;扬麦9号具有控制穗长和倒五节间长较多的显性基因。株高可能受3~4对主效基因控制,而其构成因素可能受1~3对主效基因控制。相关分析表明,株高与其构成因素呈极显著遗传正相关。株高构成因素对株高的作用大小依次为倒一节＞倒二节＞倒三节＞倒五节＞倒四节＞穗长。     

施肥和密度对小麦产量及加工品质的影响

为了探讨提高产量和改善品质的合理栽培措施,试验采用不同氮肥和密度处理,研究其对产量和品质的影响,结果表明:基本苗为225万~450万/hm2时产量差异不显著,但均比150万/hm2基本苗处理显著提高了产量。施氮270 kg/hm2比135 kg/hm2显著提高了产量。不同基本苗处理对蛋白质含量和加工品质指标影响较小,但不同施氮量对各蛋白组分、总蛋白质含量及加工品质指标有显著影响,高氮处理比低氮处理显著提高了总蛋白质和各蛋白组分含量,并显著增加了沉淀值、湿面筋含量、干面筋含量、吸水率、形成时间和面包体积。结论认为:基本苗对产量影响较大,对品质影响较小,施氮处理对产量和品质均有重要影响,适当增施氮肥可以使籽粒产量、营养品质和加工品质同步提高。     

扬麦17/宁麦18的F2群体株高QTL定位及分析

扬麦17和宁麦18均为高产小麦品种,为研究两者的株高遗传机制,以扬麦17与宁麦18杂交获得的310个F_2单株及其衍生F_(2:3)家系为材料,利用已构建的覆盖19条染色体的遗传连锁图谱,对株高性状进行QTL定位。应用复合区间作图法定位到8个株高QTL,分别位于2D、4B、5A、5B和7A染色体上,4个QTL在两世代中均检测到,其中 QPh-YN-5A.1为一主效株高QTL位点,矮秆效应来自扬麦17,LOD值为8.69和12.81,可解释14.36%和20.46%的表型变异; QPh-YN-2D.1、 QPh-YN-5B.2和 QPh-YN-7A的矮秆效应来自宁麦18,可在两世代中分别解释2.84%和6.37%、4.26%和5.46%、2.15%和3.16%的表型变异。另外4个QTL仅在单世代检测到,其中 QPh-YN-2D.2、 QPh-YN-4B和 QPh-YN-5B.1的矮秆效应来自宁麦18,可分别解释5.05%、11.24%和4.62%的表型变异, QPh-YN-5A.2的矮秆效应来自扬麦17,可解释7.72%的表型变异。     

Repellency of dimethyl disulfide to Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) under laboratory and field conditions

The mirid bug, Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae), is a major pest of cotton, fruit trees, and many other crops in China. While previous trials have found relatively low infestation levels of A. lucorum in fields treated with the acaricide dimethyl disulfide (DMDS), its mode of action has not been determined. In this study, we assessed the insecticidal and repellent action of DMDS against A. lucorum under laboratory and field conditions. DMDS did not cause mortality of A. lucorum adults or nymphs at concentrations of 10.6 and 170.9 mg a.i./1. In Y-tube olfactometer tests, both male and female A. lucorum adults preferred clean air over DMDS odors. In choice and no-choice cage trials, feeding damage and the number of A. lucorum eggs were lower on mungbean plants treated with DMDS than on control plants. Under field conditions, adult A. lucorum density was lower in DMDS-treated mungbean and cotton fields than in untreated fields, and this effect lasted 6 d, but nymph populations were not affected. Under field conditions, adult A. lucorum were repelled at a distance of up to 6 m from DMDS-sprayed cotton plants for 6 d after application. This study demonstrates the non-lethal repellent action of DMDS against adult A. lucorum and suggests its potential inclusion in integrated pest management (IPM) schemes.     

小麦矮秆基因 Rht-B1b和 Rht-D1b的检测及其验证

为研究矮秆基因 Rht-B1b、 Rht-D1b在小麦品种中的分布及其对株高的影响,以3个小麦群体（中国冬麦区白粒小麦品种、中国小麦历史品种、春小麦育种材料）共321份小麦品种为材料,检测矮秆基因 Rht-B1b和 Rht-D1b的分布频率,并分析比较它们对春小麦育种材料株高的影响。结果表明,在检测的321份材料中,共有193份材料含有 Rht-B1b矮秆基因,分布频率为60.1%,其中,中国冬麦区白粒小麦品种、中国小麦历史品种、春小麦育种材料中含有 Rht-B1b矮秆基因的材料分别有29、77和87份,分布频率分别为 34.5%、72.6%和66.4%;共有135份材料含有 Rht-D1b矮秆基因,分布频率为42.1%,其中,中国冬麦区白粒小麦品种、中国小麦历史品种、春小麦育种材料中含有 Rht-D1b 矮秆基因的材料分别有41、21和73份,分布频率分别为48.8%、19.8%和55.7%;共有78份材料同时含有 Rht-B1b和 Rht-D1b矮秆基因,分布频率为 24.3%,其中,中国冬麦区白粒小麦品种、中国小麦历史品种、春小麦育种材料中同时含有 Rht-B1b和 Rht-D1b矮秆基因的材料分别有15、17和46份,分布频率分别为17.6%、15.9%和35.1%。对已被鉴定株高表型的91份春小麦育种材料进一步分析发现,同时携带 Rht-B1b和 Rht-D1b矮秆基因的材料株高较低。     

基于重组自交系群体的小麦株高QTL分析

为了挖掘更多与小麦株高相关且适合标记辅助育种需求的QTL,采用长江中下游麦区骨干亲本扬麦158和西风配制重组自交系群体,使用55K芯片技术分析群体基因型并构建遗传连锁图,联合4个年度群体株高表型资料,对影响群体株高的QTL进行分子定位。结果表明,群体遗传连锁图含有3 830个SNP标记,覆盖2 784.9 cM,标记间平均距离0.7 cM;21条染色体共定位了39个可重复的与株高相关QTL,其中18个QTL为2个年度可重复定位,8个QTL为3个年度可重复定位,13个QTL为4个年度可重复定位,单个QTL可解释3.2%~13.6%的株高表型变异。4个年度可重复定位的QTL分别来自西风的1B、1D、4A、4B、4D、5A、5B、7A染色体以及扬麦158的3A、3D、6A、7B、7D染色体,其中扬麦158贡献的QPh·jaas-3A.3和QPh·jaas-7B.1分别解释8.4%~13.4%以及9.1%~13.1%的株高变异。这些株高QTL位点有望为长江中下游麦区小麦分子标记辅助育种提供帮助。     

小麦剩余杂合体株高的基因定位

为挖掘小麦矮秆基因,以矮秆小麦品种品冬34和高秆小麦品种Warran杂交构建的重组自交系(RIL)群体为材料,于F_(7:8)筛选出一个株高性状分离的剩余杂合体。利用BSR-seq技术对该剩余杂合体分离的高株与矮株纯系分别混池测序,进行株高位点的初步定位。结果表明,与株高性状相关的候选区域位于7B染色体687～689 Mb处,该区段内有18个候选基因。其中,TraesCS7B02G419700和TraesCS7B02G420400既参与代谢过程,又参与小麦茎的生长发育;而TraesCS7B02G418900、TraesCS7B02G419000、TraesCS7B02G419600和TraesCS7B02G420000虽在茎中表达,却未参与相关代谢过程。这6个基因特别是TraesCS7B02G419000和TraesCS7B02G420400可作为调控株高性状的候选基因进行深入研究。     

Impact of pesticide seed treatments on aphid control and yield of wheat in the Sudan

Mixtures of imidacloprid and tebuconazole, were evaluated for three consecutive growing seasons, to determine the effects on plant stand, aphid control and wheat grain yield. At rates of 1.05/0.04 and 0.7/0.04 g a.i of pesticide, respectively, per kg of seeds, plant stand per unit area increased compared with their respective untreated control. Both rates of imidacloprid efficiently controlled the maize aphid (Melanaphis maidis) and suppressed the green bug (Schizaphis graminum) for 6–8 weeks after sowing. There were substantial differences among the different treatments in the number of grains/ear and the 1000-grain weight. These differences were reflected in 90% and 30% average increase in the total grain yield of the wheat crop raised from seeds treated with the mixture relative to the corresponding untreated control and a standard mixture of lindane plus thiram, respectively. This strategy of using imidacloprid as seed dressing allowed easy application, gave adequate reliable control of aphids and less hazardous to the environment.     

铝对茶树等植物超氧化物歧化酶的影响

研究了不同物种耐铝力差异与超氧化物歧化酶（ＳＯＤ）活力的关系。结果表明，在非胁迫条件下，随着大麦、小麦种子初生根的伸长，ＳＯＤ活力逐渐下降；不同物种原初ＳＯＤ活力高低与其耐铝力相一致，即茶＞小麦＞大麦。在Ａｌ处理６～１８ｈ内，ＳＯＤ活力在Ａｌ＜０．２ｍｍｏｌ／Ｌ浓度范围内呈先升后降趋势。同功酶电泳结果表明，茶树根系ＳＯＤ比大麦和小麦多两条迁移率（Ｒｆ）小的同功酶谱带。     

小麦植株水分状况遥感监测研究进展与展望

小麦植株水分状况的实时监测和快速诊断对提高农业水分利用效率和作物产量具有关键作用。本文在概述水分监测对小麦重要性的基础上,简要介绍了植株水分遥感监测诊断技术的发展历程和研究现状,明确了不同水分诊断指标的适用条件和优缺点。最后,提出当前研究存在的问题并对发展趋势进行了展望：应加强遥感信息与土壤、气象和表型信息等数据的融合,建立新型水分诊断指标;综合利用星-机-地一体化监测体系,发展数据同化技术;优化遥感数据处理方法,建立自动化处理流程;深入研究小麦需水生理过程和调控机理,结合人工智能等现代技术,实现智能化水分管理。     

麦秸还田与化肥配施对夏玉米产量和植株性状的影响

以郑单958为材料,通过2年大田定位试验研究了麦秸粉碎覆盖还田与化肥配施对夏玉米产量和植株性状的影响。结果表明：与传统的麦秸不还田和单施化肥处理相比,麦秸覆盖还田不施化肥处理两年分别减产7.07%和28.41%,麦秸与化肥配施处理两年分别增产12.31%和9.51%。麦秸与化肥配施可以提高穗长、穗粗、穗粒数和千粒重等穗部性状,同时提高夏玉米植株的双穗率,降低空秆率,显著提高群体结实穗数。     

湖北省66份小麦品种（系）赤霉病抗性鉴定与分子检测

赤霉病是由禾谷镰刀菌引起的小麦穗部病害,严重危害小麦生产,抗赤霉病品种选育是减轻其危害的重要途径之一。本研究以湖北省不同时期审定的59个小麦品种和选育的7份优异品系为材料,采用喷雾接种对其进行田间赤霉病抗性鉴定,并利用抗性基因Fhb1功能性分子标记和主效抗性基因(Fhb2、Fhb4、Fhb5和QFhs.crc-2DL)连锁分子标记对供试材料进行检测,分析其遗传分布和利用状况;同时分析湖北小麦品种(系)赤霉病抗性、株高和小穗密度等性状年代间的差异。结果表明,16份供试材料赤霉病抗性水平达到中抗,占比24.2%,以810619品系抗性最好,病情指数略低于苏麦3号;42份材料达到中感,占63.6%。分子检测结果显示,仅鄂T45048携带Fhb1;鄂麦11、鄂麦18和810619等29份材料(43.9%)可能携带Fhb5和QFhs.crc-2DL单个或2个抗性基因,说明这2个抗性基因在湖北小麦赤霉病抗性育种中得到了较多应用。赤霉病抗性与株高的相关性分析结果显示,近15年湖北小麦品种株高持续降低,但其与赤霉病抗性无显著相关。研究结果为明确湖北小麦品种赤霉病抗性水平和分子遗传基础提供了参考。     

不同株高和抗倒性小麦品种茎秆中几种内含物的差异

为探讨不同株高冬小麦的抗倒性与茎秆内含物的关系,以矮秆抗倒品种(矮抗58、周麦17)、高秆抗倒品种(周麦30、许科1号)、矮秆不抗倒品种(中麦895、新麦18)和高秆不抗倒品种(许科196、烟农999)为试验材料,比较了四种类型小麦茎秆糖、氮、钾等内含物的差异。结果表明,不同抗倒性小麦品种茎秆总糖含量、钾含量和全氮含量随生育时期的变化趋势一致。抗倒品种茎秆具有较高的总糖含量,其积累高峰阶段是拔节至开花期,不抗倒品种茎秆的总糖积累高峰阶段是开花至灌浆期;高秆品种的灌浆期总糖积累量显著高于矮秆品种。抗倒品种灌浆期至成熟期的茎秆钾外运量较低;矮秆品种茎秆钾含量高于高秆品种,但差异不显著。在茎秆生长阶段,不抗倒品种茎秆具有较高氮积累量和外运量,矮秆品种与高秆品种间两个指标均无显著差异。经通径分析,矮秆品种对抗倒性起主要作用的是茎秆全氮含量,高秆品种为茎秆总糖和全钾含量。从几种元素相互比值看,抗倒品种有着较高的碳氮比和碳钾比,氮钾比相对较低;同一抗倒性品种株高间不同元素比值无显著差异。茎秆中各种内含物之间相互影响,直接或间接地作用于茎秆抗倒伏能力,抗倒品种茎秆在生育前期有较高的可溶性总糖积累量、合适的碳氮比和碳钾比,灌浆期以后具有较低的钾外运量,这可能是抗倒伏的原因所在,而株高不是影响倒伏的主要因素,不同株高与品种对茎秆强度的影响因素不尽相同。生产中可以通过调节拔节期追肥改变茎秆中几种内含物比例来改善茎秆抗倒性能。     

不同播期下小麦冬春性品种小花结实特性 及其与植株生长性状的关系

冬、春性小麦品种早播（9月30日）、适播（10月30日）的总小花数、可孕小花数及结实粒数均极显著高于晚播（3月2日）。晚播对春性品种小花分化发育与结实的不利影响小于冬性品种。穗粒数的多少与可孕小花数及其结实率密切相关,而与总小花数及其结实率无明显联系;同时大穗多粒基因型也以较高的可孕小花结实率为生理基础。孕穗期小花数均与叶面积、叶片重、叶鞘重和总干物重呈显著或极显著正相关,而与茎高的相关不显著。此外,冬、春性品种的结实粒数均与成熟期茎叶重、总单茎重、结实小穗数、穗长和穗粒重之间呈极显著正相关,表明良好、协调的营养生长与生殖生长的关系是改善小花发育质量、提高穗粒数的根本保证。