水氮互作对济麦20籽粒蛋白质品质及氮素和水分利用效率的影响

为给强筋小麦高产优质栽培的水氮合理运筹提供理论依据,以强筋小麦济麦20为试验材料,在大田条件下设置了3个施氮水平：0 kg·hm-2（N0）、180 kg·hm-2（N1）、240 kg·hm-2（N2）;每个施氮水平下设置4个灌水处理：不灌水（W0）、底水+拔节水+开花水（W1）、底水+冬水+拔节水+开花水(W2)、底水+冬水+拔节水+开花水+灌浆水(W3),每次灌水量60 mm,研究了水氮互作对强筋小麦济麦20籽粒蛋白质品质及其相关酶活性、产量及氮素和水分利用效率的影响。结果表明,旗叶硝酸还原酶、谷氨酰胺合成酶、内肽酶、羧肽酶和氨肽酶活性均为N2处理最高,N0处理最低。各施氮水平下硝酸还原酶活性和谷氨酰胺合成酶活性均以W0处理最低,W3处理与W1和W2处理相比,灌浆后期硝酸还原酶活性和谷氨酰胺合成酶活性提高,但各蛋白质水解酶活性降低。不施氮条件下,W3处理促进了籽粒蛋白质积累;施氮条件下,W1、W2和W3处理的籽粒蛋白质含量无显著差异。每公顷施纯氮180 kg条件下,W1处理的沉淀值高于其他灌水处理,湿面筋含量、面团稳定时间、籽粒产量、氮肥表观利用率和氮肥农学效率与W2处理无显著差异,高于W0和W3处理,水分利用效率高于W2和W3处理。综合考虑籽粒品质、产量、氮素和水分利用效率,施氮量为180 kg·hm-2、全生育期灌底水+拔节水+开花水的N1W1处理为高产优质高效的最佳组合。     

不同水氮处理对小麦耗水特性及产量的影响

为给小麦高产节水栽培提供理论依据,以百农矮抗58为材料,在大田条件下设置3个灌水水平[不灌水(W0),灌1水(W1,拔节水),灌2水(W2,拔节和开花水)]和5个施氮水平[0kg·hm-2(N0)、90kg·hm-2(N1)、180kg·hm-2(N2)、240kg·hm-2(N3)、300kg·hm-2(N4)],研究水氮处理对冬小麦耗水特性及产量的影响。结果表明,随着施氮量的增加,小麦总耗水量和土壤贮水消耗量先增加后降低,以N3处理最高,各种水分利用效率也表现出相似趋势。随灌水次数的增加,总耗水量、土壤水利用效率和降水利用效率均提高,而水分利用效率和灌水利用效率则相反。阶段耗水量均随灌水次数增加而提高,施氮对阶段耗水量的影响因灌水不同而异,其中,N2和N3处理在拔节至开花期的耗水量较高,而在开花至成熟期则较低。籽粒产量随施氮量增加呈先升后降趋势,随灌水次数增加则持续提高。综合考虑产量和生产成本,W1N3处理为本试验条件下节水高产的水氮运筹推荐模式。     

不同灌水模式对冬小麦产量及水分利用的调控效应

为明确不同灌水次数和灌水时期对小麦产量和水分利用效率的影响,在池栽条件下,以小麦品种矮抗58为材料,设置全生育期不灌水(W0)、灌拔节水(W1)、灌拔节水+孕穗水(2水,W2)和灌拔节水+孕穗水+灌浆水(3水,W3)4个处理,通过定位试验探讨不同灌水方式对小麦产量及水分利用效率(WUE)的调控效应。结果显示,与W0处理相比,3个生长季W1、W2和W3处理的平均产量分别提高37.2%、52.9%和52.7%,而平均耗水量分别增加27.1、70.4和94.9mm;灌水的增产效果在不同年份间存在差异,干旱年份的增产幅度显著大于正常年份。小麦总耗水量和WUE、产量均呈二次曲线关系,其中WUE以W1为最大,而产量以W2最大。综合考虑小麦产量和水分利用效率,正常降水年份在拔节期灌1次水、干旱年份灌拔节水+孕穗水(2水)为小麦节水高产灌溉模式。     

高产小麦花后植株氮素累积、转运和产量的水氮调控效应

为给高产小麦合理灌溉和氮肥施用提供科学依据,以小麦品种豫麦49-198为材料,在豫北高产麦田研究了不同水、氮处理对小麦花后植株氮素吸收、累积和转运的影响。试验采取灌水与施氮量两因子裂区设计,其中灌水为主区,设全生育期不灌水(W0)、拔节期灌1水(W1)和拔节水+开花水灌2水(W2)3个水平;施氮量为副区,设置4个水平,即每公顷施纯氮量0kg(N0)、180kg(N1)、240kg(N2)和300kg(N3)。结果表明,W1和W2下小麦籽粒产量较W0分别提高16.6%和25.6%,蛋白质产量分别提高14.2%和19.2%。籽粒产量和蛋白质产量的提高与氮素积累和转运有关。灌水增加了茎鞘、叶片和颖轴的氮素累积量,提高了茎鞘氮素转运效率和贡献率,但减小了叶片氮素转运量、转运效率和贡献率。施氮可显著增加小麦花后植株氮素累积量及氮素转运量,进而提高小麦籽粒氮素累积量和蛋白质产量。与N0相比,成熟期N1、N2和N3籽粒氮素累积量分别增加44.9%、59.3%和60.2%,叶片贡献率分别增加60.2%、40.9%和61.5%,籽粒产量分别提高75.3%、73.5%和79.8%。水氮互作显著影响叶片氮素累积量和氮素转运效率,但对籽粒产量和蛋白质产量影响不显著。综合来看,在豫北高产条件下,不灌水或灌1水时小麦适宜施氮量为180~240kg·hm-2,灌2水时适宜施氮量为240kg·hm-2。     

水氮限量供给下两个高产小麦品种氮素吸收与利用特征

为给华北地区冬小麦节水高产高效栽培提供理论依据,选用当地两个主栽冬小麦品种济麦22和石麦15为材料,在大田春灌一水(W1)和春灌二水(W2)2个灌水条件下均设置192kg.hm-2(N1)和270kg.hm-2(N2)2个施氮水平,研究了在水氮限量供给下冬小麦氮素吸收利用特征。结果表明:(1)在W1水平下,济麦22籽粒产量N1与N2处理无显著差异,石麦15籽粒产量N1处理显著高于N2处理;在W2水平下,两个小麦品种均以N1处理籽粒产量最高;在相同施氮水平下,两个小麦品种籽粒产量均以W2处理最高;在不同水氮处理下,济麦22籽粒产量高于石麦15。(2)在相同灌溉水平下,两品种氮素利用效率和氮肥生产效率均以N1处理较高;在相同施氮水平下,两个品种氮素利用效率和氮肥生产效率均以W2处理较高;在不同水氮处理下,济麦22氮素利用效率和氮肥生产效率高于石麦15。(3)在相同灌溉水平下,两小麦品种花后氮素积累量和分配比例均以N1处理最高;在相同施氮水平下,两小麦品种花后氮素积累量和分配比例均以W2处理最高。在不同水氮处理下,石麦15花后氮素积累量和分配比例高于济麦22。(4)方差分析表明,灌溉、品种、氮肥以及氮肥与品种、灌溉与氮肥的互作对籽粒产量影响均达显著水平,其中灌溉效应起主导作用。综合分析认为,两个小麦品种在限量供水(W2水平)、适量供氮(N1)处理下可以协调促进花后氮素积累、分配和有效转运,获得高产、高氮素利用效率和高氮肥生产效率。     

水氮限量供给下两个高产小麦品种物质积累与水分利用特征

为给小麦节水高产高效栽培提供科学依据,以主栽小麦品种济麦22和石麦15为材料,在大田条件下,设置2个灌水水平[春灌一水(W1)和春灌二水(W2)],在每个灌水水平下设置2个施氮量处理[192kg.hm-2(N1)和270kg.hm-2(N2)],探讨了有限水氮供给条件下两品种的干物质生产与水分利用特征。结果表明:(1)在W1水平下,济麦22的N1与N2处理籽粒产量和水分利用效率无显著差异,石麦15的N1处理籽粒产量和水分利用效率显著高于N2处理;在W2水平下,两品种籽粒产量和水分利用效率均以N1处理较高;在相同施氮水平下,两品种籽粒产量和水分利用效率均以W2处理较高;在不同水氮处理下,济麦22籽粒产量和水分利用效率高于石麦15。(2)在相同灌溉水平下,两品种花后物质积累量和分配比例均以N1处理高于N2处理;在相同施氮水平下,两品种花后物质积累量和分配比例均以W2处理高于W1处理;2个品种比较,石麦15花后物质积累量和分配比例高于济麦22,而济麦22花前物质积累量及其对产量的贡献率高于石麦15。(3)在不同水氮处理下,济麦22总耗水量、土壤贮水消耗量及花后耗水比例均大于石麦15。综合上述结果认为,两小麦品种在W2N1水氮组合下可实现高产与水分高效利用的协调统一。     

水氮对冬小麦花后籽粒淀粉含量及产量的影响

为进一步探索水分和氮肥对小麦淀粉含量和产量的影响,以冬小麦品种矮抗58为材料,在小麦全生育期不灌水(W0)和拔节期灌水(W1)两种水分条件下,分析了不同施氮处理间(0、180、240和300kg·hm 2,分别用N0、N1、N2、N3表示)冬小麦花后籽粒淀粉含量和产量的差异.结果表明,N2处理获得较高小麦籽粒产量、支链淀粉和总淀粉含量及较低直/支比,不施氮或施氮过多均不利高产和籽粒淀粉积累.与W0相比,W1处理有利于小麦籽粒产量提高及支链淀粉和总淀粉积累.水、氮互作对小麦籽粒产量和淀粉含量影响明显.在8个处理中,以W1N2处理对提高小麦籽粒产量和改善籽粒淀粉品质有利,为比较理想的水氮运筹方式.     

不同灌水次数和施氮量对冬小麦群体动态和产量的影响

为了明确灌水次数和施氮量对高产冬小麦群体动态和产量的影响,分别于2006-2007、2007-2008年度在保定市和藁城市用当地冬小麦推广品种河农822和石新616研究了不同灌水次数(在保证底墒基础上全生育期灌0、1、2和3水,分别用W0、W1、W2和W3表示)和施氮量(0、112.5和225 kg/ha,分别用N0、N1和N2表示)对小麦群体动态和产量的影响.结果表明,2006-2007年度灌水次数和施氮量对小麦总茎(穗)数的影响较显著.W1、W2和W3的成穗数显著高于W0,W1、W2、W3之间差异不显著.3个施氮水平间各生育时期的总茎数均差异显著,且随施氮量增加而增大.大部分生育时期不同灌水次数的LAI差异不显著,而不同施氮量的LAI差异显著,N2的LAI显著高于N1和N0.灌水次数对穗数和千粒重影响显著,施氮量对穗数和穗粒数影响显著,以致灌水次数和施氮量对小麦产量的主效应均达到显著标准.4种灌水水平的产量以W3最高,W0最低;3个施氮量中N1产量最高,N0最低.灌水次数和施氮量对小麦产量和各产量构成因素的交互作用显著,W0和W1条件下产量随施氮量增加而提高,而W2和W3条件下N1产量最高,且与N0差异显著.2007-2008年度试验中,灌水次数和施氮量对各生育时期的总茎数、LAI和产量的影响均不显著.根据本研究结果可知,在河北平原地区常年降水(小麦全生育期100 mm左右)和中等肥力条件下全生育期灌溉3次,施氮量为N 112.5～225 kg/ha以及丰水降雨年份和较高肥力条件下全生育期灌溉1或2次,相应地施氮225或112.5 kg/ha,可以分别取得较理想的产量.     

基于APSIM模型的陇中旱地春小麦产量对播期、施氮和降水量变化的响应模拟

为探讨播期调控和水氮优化对小麦（Triticum aestivum L.）产量的耦合效应,在甘肃省定西市安定区李家堡乡田间试验调试参数的基础上,基于APSIM平台设置播期和水氮耦合情景［播期设早播(3月3日)、正常播(3月18日)和晚播(每年3月31日),分别用ESW、NSW和LSW表示;降水设以当年自然降水为基础减少20%、减少10%、不变、增加10%和增加20%等5个梯度,分别用W1~W5表示;施氮量设0、 52.5、105、157.5和210 kg·hm^-25个梯度,分别用N1～N5表示］,对2000-2018年不同处理的春小麦产量进行了模拟,定量分析了不同降水年型下最佳播期和水氮管理耦合方案。结果表明,基于APSIM-wheat模型,春小麦不同播期模拟产量的归一化均方根误差在5%以内,模型的有效性指数均大于0.5,说明此模型在研究区具有较好的拟合度和适宜性。经回归分析,限制小麦产量因素的影响程度表现为降水量>施氮量>播期。从不同耦合方案的产量及产量年际变率看,该地区春小麦在干旱年,晚播W5N3（降水量增加20%施氮量为105 kg·hm^-2）处理下可获得最优产量3 803.77 kg·hm^-2;平水年,正常播W4N3（降水量增加10%施氮量为105 kg·hm^-2）处理下可获得最优产量4 390.93 kg·hm^-2;湿润年时,晚播W5N4（降水量增加20%施氮量为157.5 kg·hm^-2）处理可获得最优产量4 657.88 kg·hm^-2。     

水氮交互对弱筋小麦蔗糖含量和籽粒淀粉积累及品质的影响

为了解弱筋小麦产量和品质的水氮调控效应,于2003~2004年度在大田条件下研究了水氮因素及其交互作用对弱筋小麦旗叶蔗糖合成、籽粒淀粉积累、产量和品质性状的影响。结果表明,就弱筋小麦品种豫麦50而言,150kg/hm2的氮肥用量有利于促进旗叶蔗糖合成,增加籽粒淀粉积累量和籽粒产量,而氮肥施用量过多(270kg/hm2)或全生育期不施氮肥均不利于弱筋小麦产量和品质的形成;在试验条件下,灌拔节水 灌浆水(花后15d)有利于后期旗叶蔗糖合成和籽粒淀粉积累,其籽粒产量最高,品质性状最优;而灌拔节水(1水)或拔节水 灌浆水 麦黄水(3水)均不利于旗叶蔗糖合成和籽粒淀粉积累,导致籽粒产量和品质不同程度的下降。从水、氮的交互效应看,以全生育期施氮量150kg/hm2并保证拔节水和灌浆水是弱筋小麦较为理想的水氮运筹方式。     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

<Emphasis Type="Italic">Pulque</Emphasis>, An Alcoholic Drink from Rural Mexico,Contains Phytase. Its <Emphasis Type="Italic">in vitro</Emphasis> Effects on Corn Tortilla

Pulque is made by fermenting the agave sap or aguamiel of Agave atrovirens with a whole array of microorganisms present in the environment including several lactic acid bacteria and yeasts such as Saccharomyces cerevisiae. Ascorbic acid was determined in pulque and aguamiel, respectively. Phytase activity in lees, liquid and freeze-dried pulque was assayed by measuring the appearance of phosphate from phytate by a colorimetric method likewise phosphate from phytate present in fresh corn tortilla was measured after in vitro incubation with pulque. Iron, zinc, calcium, magnesium and selenium contents were measured in pulque and corn tortilla as well as in nixtamalized corn flour (NCF), the latter is used to make instant tortilla, since corn provides most of the energy as well as most of the phytate in the Mexican rural diet. Pulque showed phytase activity but much less ascorbic acid and iron than previously reported; additionally, phytase in pulque hydrolyzed most of phytate’s corn tortilla. Lees, which is mostly made of pulque’s microbiota, significantly accumulated iron and zinc but no selenium. NCF was fortified with iron by the manufacturers but poorly blended. There were significant differences on selenium content between tortillas samples, apparently some soils in central Mexico are selenium deficient. Moderate pulque intake appears to increase the bioavailability of iron and zinc bound by phytate in corn.