The influence of different nitrogen treatments on the size distribution of protein fractions in hard and soft wheat

The relative quantity of specific proteins, protein subunits, as well as amount and size-distribution of polymeric proteins in wheat kernels may vary due to environmental conditions. In this study, the effect of different nitrogen treatments on polymeric and monomeric proteins in wheat was determined. Two soft white biscuit wheat cultivars, a cracker wheat and a hard red bread wheat were planted under irrigation in a randomized complete block design with three replications in two successive years at six different nitrogen treatments. SE-HPLC was used to determine the amount of monomeric and polymeric proteins, and various quality characteristics were measured after harvesting. The large and small SDS-extractable polymeric proteins were not influenced by different N levels. There was a strong cultivar influence, where some cultivars had a larger reaction to N treatments than others. The later application (at flag leaf stage) of nitrogen did not increase the protein fractions. The total amount of N given seemed to have a greater influence on the protein fractions than the timing of the fertilizer application. The lowest N treatment consistently gave the lowest flour protein content value. There was a strong correlation between flour protein content and large monomeric proteins.     

Size Characterisation of Glutenin Polymers by HPSEC-MALLS

The use of an on-line coupling of a new high-performance size exclusion chromatography (HPSEC) phase characterised by a very high exclusion limit and a multiangle laser light scattering detection (MALLS) for the size characterisation of wheat glutenin polymer was examined. Flour glutenin polymers which were extracted and purified by differential solubility in aqueous 50 and 70% propan-1-ol were solubilised with or without sonication in combination with a surfactant, 2% SDS. The glutenin polymers of the two genotypes studied, Soissons (5+10, Glu-1D) and Thésée (2+12, Glu-1D), were characterised by large polydispersity and by significant differences of size distribution of total polymers. The molecular size distribution of the total polymers, which can be used to differentiate the two genotypes, was highly correlated with the percentage of high-molecular glutenin subunits (HMW-GS) in glutenins. Furthermore, the results obtained for both the SDS-soluble and SDS-insoluble glutenin polymers from the two varieties revealed significant differences in size distribution, and also in molecular conformation (dependence of size upon mass). The molecular dimensions of SDS-insoluble polymers increased more slowly with the molecular weight than SDS-soluble polymers, which suggested a more compact structure. To conclude, the method appears to be a viable procedure to obtain rapid size characterisation of unreduced glutenin.     

施氮量对强筋小麦产量、氮素利用率和品质的影响

为探明协同提高强筋小麦产量、氮素利用率和品质的施氮量,以强筋小麦品种济麦20（中穗型）和洲元9369（大穗型）为材料, 研究了180、240和300 kg·hm^-2三个氮肥水平（分别用N180、N240和N300表示）对强筋小麦产量、氮素利用率、品质及其相关指标的影响。结果表明,相同施氮量下,洲元9369的产量、氮素利用率、面团形成时间、面团稳定时间、面包体积和面包评分均高于济麦20。当施氮量由N180增至N240时,2个品种的产量无显著变化,但沉降值、面团形成时间、面团稳定时间、面包体积和面包评分均显著提高;施氮量增至N300后,2个品种的产量和品质又都显著下降,籽粒总蛋白含量、谷蛋白含量、SDS-不可溶性谷蛋白含量、醇溶蛋白含量和谷蛋白聚合指数均明显降低,而SDS-可溶性谷蛋白含量和谷醇比却表现为上升趋势。经相关分析,SDS-不可溶性谷蛋白含量、谷蛋白聚合指数与面团形成时间、面团稳定时间、面包体积和面包评分均呈显著正相关。以上结果表明,谷蛋白聚合程度降低是过量施氮条件下强筋小麦品质下降的主要原因。综合考虑小麦产量、氮素利用率和籽粒品质,240 kg·hm^-2为本研究条件下的最佳施氮量。     

磷肥用量对超级早稻生长、产量及磷吸收利用的影响

以超级早稻中早39和普通早稻金早09为材料,研究比较了不同施磷量对超级早稻生长、产量及磷吸收利用的影响。结果表明,分蘖中期,在P0和P1处理条件下,中早39的生物量显著低于金早09,但是齐穗期以后,所有磷肥用量处理下,中早39的生物量及产量均高于金早09。施用磷肥能显著提高2个品种的有效穗数,但P1和P2处理间中早39的有效穗数无显著差异。 P1和P2处理下中早39的氮、磷吸收量显著高于金早09,磷肥吸收利用率和磷肥偏生产力也高于金早09,但是磷肥农学利用率低于金早09。随着施磷量的增加,中早39的有效穗数和产量增加量均小于金早09,同时中早39的磷肥吸收利用率、农学利用率和磷肥偏生产力下降程度均高于金早09。综上所述,超级稻中早39对磷肥的敏感性低于普通早稻金早09,最适磷肥（纯P）用量为30 kg/hm2。     

Winter wheat genotypes under different levels of nitrogen and water stress: Changes in grain protein composition

Hard white winter wheat with superior and consistent quality is preferable for Asian markets. This study investigated the combined influences of moisture deficit during grain-fill and N management on protein quality, dough rheological properties, and protein molecular weight distributions in soft and hard winter wheats. Genotypes were grown under an irrigation gradient and two N-fertilization levels. Grain polyphenol oxidase (PPO) activity, SDS sedimentation, and Mixograph analyses were evaluated. Flour protein composition was characterized using SE-HPLC. Moisture stress during grain-fill increased flour protein content. N fertilization increased flour protein content. No significant correlation was found between flour protein and PPO. Changes in protein composition were related to general increases in protein content, regardless if the result of reduced irrigation or increased fertilization rate. The percentage of monomeric proteins increased more than the polymeric proteins as flour protein increased. Similarly, SDS sedimentation volume increased as a function of protein content. As expected, subunit GluD1 5+10 was associated with larger sedimentation volume and higher dough strength in genotypes as compared to those with subunit GluD1 2+12. Biplot analyses showed that genotypes of similar protein quality and composition responded similarly to N and irrigation treatments.     

Effects of differential rates of nitrogen and phosphorus on early blight in potatoes

The Kennebec variety of potato was exposed toAlternana solani inoculum during the 1970 and 1971 seasons to determine the effects of differential rates of nitrogen and phosphorus on the incidence of early blight. Both high nitrogen and low phosphorus treatments significantly reduced the incidence of early blight and the combination of high nitrogen and low phosphorus consistently gave the lowest incidence of the disease during both years. The data suggest that this combination of nutrients may be related to early blight resistance in the plant by extending the period of meristematic activity permitting the plant to wall off infection. Yield data indicated that there was too great a yield difference between fertilization for optimum early blight control and fertilization for optimum yield. Therefore, in Maine, potatoes should be fertilized for optimum yield with a reasonable specific gravity, and early blight should be controlled by the application of fungicides and sanitation measures.     

The origin and early development of wheat glutenin particles

Breadmaking quality is strongly related to the glutenin macropolymer (GMP) fraction. Don and co-workers [Don, C., Lichtendonk, W.J., Plijter, J.J., Hamer, R.J., 2003a. Glutenin macropolymer: a gel formed by particles. Journal of Cereal Science 37, 1–7] showed that GMP consists of spherical glutenin particles and suggested that these originate from the protein bodies (PBs) observed in developing grain. We have tested this hypothesis by systematically comparing SDS-soluble and SDS-insoluble protein fractions from both PBs and flour. These preparations were analysed at the molecular, oligomer, particle and microscopic levels. Comparison of PBs isolated from immature seeds with glutenin particles isolated from mature seeds revealed strong similarities in protein composition and the presence of large glutenin oligomers. However, the glutenin particles from mature wheat were significantly larger than PBs. We suggest that PBs are the building blocks for the formation of much larger glutenin particles which are formed during the desiccation phase of kernel development.     

小麦淀粉合成关键酶基因和相关蛋白表达对不同施磷量的响应

为深入研究磷素在小麦淀粉产量和品质形成过程中的作用,以新疆冬小麦主栽品种新冬20号为试验材料,研究0 kg·hm^-2（CK）、105 kg·hm^-2（LP）和210 kg·hm^-2（HP）3种施磷（P₂O₅）量对小麦籽粒灌浆特性、淀粉合成关键酶(AGPase和GBSS)活性和基因表达、胚乳可溶性蛋白和淀粉粒结合蛋白含量及谱带特征、胚乳微观特性等的影响。结果表明,籽粒灌浆后期磷肥对粒重的促进作用逐渐增强;低磷（LP）条件下, agp1、 agp2、 gbss1、 gbss2基因表达量显著提高;3个处理下AGPase活性的变化趋势基本一致;籽粒灌浆中期（14～21 d）,低磷处理的GBSS活性显著高于CK;不同磷处理对淀粉粒结合蛋白和胚乳可溶性蛋白含量的影响显著,但对蛋白谱带特征的影响较弱。扫描电镜结果显示,不同磷处理的胚乳淀粉粒形态未发生明显变化;与CK和高磷（HP）处理相比,低磷处理下籽粒胚乳横断面蛋白基质较少,淀粉粒与蛋白质结合较疏松。说明常规施磷（低磷）条件下,淀粉合成关键酶基因（agp和gbss）相对表达量提高或酶活性变化可影响籽粒淀粉合成及胚乳中蛋白与淀粉粒的嵌合度,并最终造成粒重的增加和淀粉特性的变化。     

长期隔年施磷对陇东旱塬作物产量和土壤肥力的影响

为探讨不同施肥方式对旱地土壤的培肥作用及增产效果,以1979-2019年在甘肃省陇东旱塬黑垆上土进行的长期定位施肥试验为基础,研究了不施肥料(CK)、单施氮肥(N)、氮磷肥配施(NP)、秸秆还田+氮磷肥配施(磷肥为隔年施用,施磷年份该处理记为SNP,不施磷年份记为SN)4种措施对作物产量、产量稳定性和可持续性以及土壤综合肥力的影响。结果表明,长期隔年施磷(SN)的春玉米和冬小麦产量分别较CK增加151.4%和159.2%,较长期施磷处理(SNP)增加8.6%和6.9%;SN的春玉米产量稳定性和可持续性均低于N和NP处理,而冬小麦产量稳定性和可持续性均优于N和NP处理;SN处理显著提高了耕层土壤综合肥力(IFI),其耕层土壤IFI值分别较CK、N和NP处理高25.5%、21.3%和6.1%,年际间变异强度高于CK和N处理。说明,在陇东旱塬黑垆土春玉米-冬小麦轮作体系下,采用秸秆还田+氮磷配施隔年施磷技术,既在减少50%化学磷肥投入的情况下仍能保证作物产量稳定和持续,并能有效提高耕层土壤综合肥力。     

The origin and early development of wheat glutenin particles

Breadmaking quality is strongly related to the glutenin macropolymer (GMP) fraction. Don and co-workers [Don, C., Lichtendonk, W.J., Plijter, J.J., Hamer, R.J., 2003a. Glutenin macropolymer: a gel formed by particles. Journal of Cereal Science 37, 1–7] showed that GMP consists of spherical glutenin particles and suggested that these originate from the protein bodies (PBs) observed in developing grain. We have tested this hypothesis by systematically comparing SDS-soluble and SDS-insoluble protein fractions from both PBs and flour. These preparations were analysed at the molecular, oligomer, particle and microscopic levels. Comparison of PBs isolated from immature seeds with glutenin particles isolated from mature seeds revealed strong similarities in protein composition and the presence of large glutenin oligomers. However, the glutenin particles from mature wheat were significantly larger than PBs. We suggest that PBs are the building blocks for the formation of much larger glutenin particles which are formed during the desiccation phase of kernel development.     

全周期胶园间作对豆薯和大豆的产量、品质和土壤速效养分的影响

研究在全周期胶园宽行间作豆薯和大豆的产量、品质和土壤速效养分的影响。结果表明,与单作相比,间作大豆产量显著降低40%(p0.05),间作豆薯产量略低但差异不显著(p0.05)。总体上,单作和间作处理豆薯和大豆不同位置的可溶性糖、淀粉、粗蛋白和粗脂肪的含量没有显著差异(p0.05),但间作提高了间作带中间区域豆薯的粗脂肪含量。单作豆薯和大豆平均土壤铵态氮、硝态氮均显著高于间作处理的不同位置(p0.05);单作豆薯和大豆土壤速效钾含量高于间作处理且显著高于单作小区两侧(p0.05);而单作豆薯和大豆土壤速效磷则低于间作处理,其中单作豆薯显著低于间作豆薯小区中间区域(p0.05)。综上所述,豆薯比大豆更适合间作于全周期胶园,间作对作物的品质总体上没有影响,但对降低土壤无机氮含量较明显。     

不同供磷水平对火龙果幼苗生长及养分吸收的影响

火龙果是热带地区重要的经济作物,近年来种植规模不断扩大,然而关于火龙果对磷吸收以及响应规律的研究仍然极其匮乏。本研究以‘软枝大红’火龙果为材料,采用盆栽方式,分析不同施磷水平（0、25、50、100、200 mg/kg）下火龙果幼苗根系形态和养分吸收量的差异,探究火龙果幼苗生长适宜的磷供应浓度。结果表明：火龙果幼苗在供磷水平25 mg/kg和50 mg/kg,地上部生物量分别为37.1 g/株和36.2 g/株,显著高于其他处理;供磷水平未影响地上部磷和钾吸收,但当供磷水平在50 mg/kg时,氮吸收量显著高于供磷水平0、100和200 mg/kg处理;火龙果幼苗在供磷水平25 mg/kg和50 mg/kg,总根长分别为1068.8 cm和1069.6 cm,显著高于其他处理;供磷水平50 mg/kg的根表面积显著高于0 mg/kg和200 mg/kg处理;土壤碱解氮含量和总根长及根表面积呈显著负相关,表明供磷水平通过影响根系生长间接影响火龙果幼苗对氮素的吸收。综上所述,供磷水平在50 mg/kg可改善火龙果幼苗根系形态,促进幼苗对氮素吸收。     

氮、磷节约高产型水稻品种筛选

为筛选氮、磷节约高产型水稻品种,以正常施肥条件下的F优498和宜香2115作为对照,选取贵州省水稻研究所近年来选育的12个杂交籼稻新品种(组合)为材料,设置不同减氮处理和减磷处理,比较这些新品种(组合)在减肥条件下的产量和肥料利用率。结果表明,成优981、成优33、汕优108、D44/QR35、成优489等5个品种(组合)在减氮45 kg/hm^2的条件下较正常施氮的对照品种平均增产3.97%,属节氮高产型品种;汕优108和D44/QR35在减磷37.5 kg/hm^2的条件下较正常施磷的对照品种平均增产3.20%,属节磷高产型品种。节肥高产型水稻品种具有较多的每穗粒数和更大的群体颖花量。     

磷胁迫下氮形态对苗期玉米氮素吸收与分配的影响

采用营养液培养的方法,比较Ca_3(PO_4)_2模拟磷胁迫条件时3种氮处理(NO_3~--N、NH_4~+-N、NO_3~--N+NH_4~+-N)对玉米氮素吸收与分配的影响。结果表明,与KH_2PO_4处理相比,磷胁迫处理时,硝态氮、铵态氮及铵硝混合营养处理的玉米整株生物量分别降低38.1%、17.4%和20.8%;与此同时,铵态氮处理的玉米植株全氮、氮素累积量、有机氮及硝态氮含量显著升高,而硝态氮处理时全氮、氮素累积量、有机氮显著降低,硝态氮含量无明显变化;此外,与硝态氮及铵硝混合处理相比,铵态氮处理的玉米叶中可溶性蛋白含量下降幅度最大,而游离氨基酸、脯氨酸含量下降幅度最小。因此,本试验中,铵态氮处理的玉米更耐磷胁迫,表现为增加了氮的吸收和积累以及增强可溶性蛋白降解为氨基酸的过程。     

Effect of mycorrhizae, Thiobacillus and sulfur nutrition on the chemical composition of soybean [Glycine max (L.)] Merr. seed

A field experiment carried out in a calcareous soil with a low available phosphorus to evaluate effectiveness of biofertilizers, mycorrhizae (Glomus intraradices) and Thiobacillus sp. inoculation individually or in combination on seed yield, oil, protein and some elements (P, Fe, Mn, Zn) concentration in two soybean [Glycine max (L.) Merr.] cultivars. The applied treatments were different fertilizers with 6 levels (including: NP (control, 12 kg N ha(-1) as urea, 46 kg P2O5 ha(-1) as triple super phosphate); NPK (NP + 75 kg K2O ha(-1) as potassium sulphate); NPKS [NPK+ S (100 kg S ha(-1))]; NPKST (NPKS + seed inoculation with Thiobacillus bacteria); NPKM (NPK + Seed inoculation with mycorrhizae fungi) and NPKSTM (NPKS + seed inoculation with Thiobacillus and mycorrhizae) and two cultivars (JK and 032). Before planting, soybean seeds were inoculated by Bradyrhizobium japonicum in all treatments. Results showed that combined inoculation of biofertilizers increased yield, however the highest yield was observed in treatment NPKST. Increasing oil content (percentage) was more pronounced in treatments NPKM, while most protein content (percentage) increasing was observed in NPKS and NPKM. Fe and Zn concentrations were unaffected significantly by fertilizer treatments, but NPKSTM showed significantly higher value of seed's Mn concentration compared to treatments NP and NPK. Although no significant difference was observed in terms ofP concentration of 032 line among fertilizer treatments, JK cultivar and NPKSTM caused a significant increasing in P concentration compared to NP, NPKS and NPKM. Present results suggested that applying biofertilizers i.e., mycorrhizae and Thiobacillus increased soybean yield compared to control (NP). Overall, this study demonstrated that soybean seed yield and its chemical composition could be affected by biofertilizer inoculation.     

基于高通量测序技术分析不同耕作方式下水稻根际土壤真菌多样性

为研究不同耕作方式下水稻根际土壤真菌群落多样性,本研究以旋耕、免耕和粉垄耕作处理的水稻根际土壤为研究对象,采用高通量测序技术分析了真菌群落结构和多样性,并结合土壤环境因子进行相关性分析。结果表明：3种耕作处理水稻根际土壤中优势菌门为子囊菌门、接合菌门、担子菌门和球囊菌门,优势菌属为镰刀菌属、被孢霉属、Pyrenochaetopsis、柄孢壳属、毛壳菌属、支顶孢属、隐球菌属、Westerdykella、顶囊壳属、绿僵菌属。接合菌门和被孢霉属、支顶孢属、隐球菌属、顶囊壳属真菌相对丰度在不同处理间差异显著。Alpha多样性指数分析显示,3种耕作处理间无显著差异。PCoA分析表明,不同耕作处理下的土壤真菌群落分布特征存在明显差异。冗余分析表明前两个排序轴共解释了3种耕作处理间土壤真菌群落变化的87.46%。相关性分析显示,土壤pH与接合菌门真菌丰度呈极显著正相关关系,土壤速效磷、碱解氮和有机质含量与接合菌门真菌丰度呈极显著负相关关系,土壤速效磷与担子菌门真菌丰度呈显著正相关关系。综上表明,短期不同耕作方式处理下水稻根际土壤真菌群落结构和多样性存在差异,不同处理下真菌群落分布受土壤pH值、有机质、碱解氮和速效磷影响。     

氮磷钾配施对鸦胆子养分吸收与分配的影响

运用“3414”不完全正交回归设计,采用盆栽试验,研究了氮磷钾配施对鸦胆子养分吸收与分配的影响。结果表明,施氮处理显著提高了鸦胆子叶、茎、根氮浓度,其中叶氮浓度最高,但对磷和钾素的吸收影响不显著。土壤氮亏缺时,植物将较多的氮、磷和钾素分配到根部。供磷和供钾水平对鸦胆子氮、磷和钾素的吸收分配规律的影响均不显著,氮磷、氮钾和磷钾施肥处理之间的交互作用不明显,叶片氮、磷、钾浓度的大小受氮肥施用量的变化影响较大。不同施肥处理条件下,鸦胆子植株对磷的吸收量最多,钾次之,氮最少,其氮、磷、钾的吸收比例平均为1∶1.4     

不同控释氮肥运筹对粳稻养分吸收与氮素利用的影响

以绥粳18为供试材料,通过盆栽试验,在一次性施入控释氮肥免追肥条件下,设置不同施肥量(高、中、低、无)和施肥深度(5 cm、10 cm),探讨不同氮肥施用方式对粳稻养分吸收和氮素利用的影响。结果表明,在不同氮肥运筹条件下,粳稻各生育期氮、磷、钾的吸收、转运均存在明显的协同效应,施肥深度5 cm组,随着氮肥施用量的增加,粳稻的氮吸收总量增加,同时可促进磷的吸收,但影响幅度较小。钾变化与氮、磷变化有所不同。施肥深度10cm组,施高量氮肥抑制了粳稻对磷的吸收、减少了对氮的吸收,但有利于提高氮素利用率,对钾的吸收无显著影响。施用树脂包膜控释肥,纯氮用量为153 kg/hm^2、施肥深度5 cm、一次性施肥免追肥可获得最优水稻氮素利用效率并显著提高磷钾肥利用效率。     

不同氮磷钾施用量对杂交粳稻产量的影响

通过进行不同氮磷钾肥施用量对杂交粳稻产量及其构成因素影响的研究,结果表明:辽优5218和辽优5238在高氮量处理区能明显提高成穗率,中氮量和高氮量之间对辽优5238成穗数影响差异不大;辽优5238分蘖速率对于磷肥用量的增加并不敏感;辽优5218在高磷量下前期分蘖加快,有效分蘖率下降;过高或过低钾肥用量对辽优5218分蘖没有明显促进作用;辽优5218在高氮高磷和中钾肥量的条件下,产量明显高于其他处理,而辽优5238则可以在低氮、低磷、低钾条件下获得较高产量。     

吉林省半干旱区春玉米干物质与氮、磷、钾养分累积与分配

在大田条件下研究4种栽培方式(农户习惯、高产高效、高产、保产增效)产量构成、干物质及氮、磷、钾的累积转运特征.结果表明,高产栽培方式下产量最高,为11 135.8 kg/hm²,较农户习惯增产112.7%.高产高效栽培方式下玉米生育后期子粒干物质分配比例高于其他3种栽培方式;成熟期后高产栽培方式下氮素子粒分配比例最高,保产增效栽培方式下磷素子粒分配比例最高.农户习惯栽培方式下子粒氮、磷、钾累积量与转运量显著低于其他3种栽培方式.高产高效栽培方式下子粒氮、磷、钾累积量最大,氮、磷、钾转运量保产增效栽培方式下最大.高产高效栽培方式下子粒中钾的累积比例显著低于氮、磷,其钾转运贡献率比氮、磷转运贡献率高20%~200%.