氮磷钾不同配比对饲用稻威优198产量及糙米蛋白含量的影响

采用田间小区试验研究“推荐配比”(N:P2O5:K2O比率为190:90:100 kg hm-2)、“高氮量配比”(N:P2O5:K2O比率为210:90:100 kg hm-2)、“低氮量配比”(N:P2O5:K2O比率为170:90:100 kg hm-2)以及“常规配比”(N:P2O5:K2O比率为216:112.5:202.5 kg hm-2)4种氮、磷、钾配比施肥对饲用稻威优198蔗糖合成酶(SUS)、腺苷二磷酸焦磷酸化酶(AGPase)、硝酸还原酶(NR)、谷氨酰胺合成酶(GS)以及产量和糙米蛋白质的影响。结果表明:“推荐配比”能提高不同生育时期水稻功能叶(旗叶)和粒籽中碳、氮代谢关键酶的活性,这些关键酶活性的变化显著影响水稻产量和糙米全氮以及蛋白氮的含量。统计(P0.05)结果证实“推荐配比”能提高水稻产量达到8200 kg hm-2,与“常规配比”相比产量提高了24.81%;“推荐配比”糙米全氮和蛋白氮含量分别达到22.70 g kg-1和21.98 g kg-1,与“常规配比”相比差异显著,并且其全氮和蛋白氮含量分别提高17.01%,18.38%。     

Irrigation Module and Sowing Date Affect Seed Cotton Yield,Quality, Productivity Indices,and Economics of Cotton in North-western India

ABSTRACT

Delayed sowing and imprecise application of irrigation water to cotton has been the major hurdle in sustaining cotton yield in north-western India. Therefore, studies were initiated to ascertain the impact of heavy or normal level of presowing irrigation (PSI), scheduling time of first postsowing irrigation (POSI) under two sowing dates (SDs) on cotton arranged in a split block design replicated thrice. PSI_h (100 mm) recorded 23.2% higher seed cotton yield over PSI_n (70 mm) owing to better yield attributes and higher stand. First POSI at 4 weeks after sowing (WAS) resulted the highest yield (3072 kg ha^?1), while one at 6 WAS (POSI₆) recorded least due to poor population and reduced yield attributes. Water productivity under POSI₆ was lesser by 29.1%, 25.2%, and 16.2% as compared to POSI₃, POSI₄, and POSI₅, respectively. April sown crop out yielded the May sown cotton crop by 939 kg ha^?1 due to better yield attributes. Nitrogen factor productivity (NFP) among SD remained higher by 23.3% for April as compared to May sowing. PSI_h exhibited better NFP over PSI_n. POSI₆ recorded least NFP by 24.4%, 28.5%, and 16.3% as compared to POSI₃, POSI₄, and POSI₅, respectively and was indicative of relatively poor utilization of N under delayed schedules. Therefore, planting in April after heavy PSI and scheduling first POSI at 4 WAS is best strategy for sustaining cotton yield and maximizing farmer profitability.     

黑龙江农田土壤壬基酚及其短链聚氧乙烯醚残留调查

对黑龙江土壤样品中的壬基酚(NP)、壬基酚一氧乙烯醚(NP1EO)和壬基酚二氧乙烯醚(NP2EO)的残留状况开展研究。结果表明,NP、NP1EO和NP2EO均有不同程度的检出,检出率在68.46%~95.38%之间;NP、NP1EO和NP2EO的浓度分别为ND~156.8μg kg-1、ND~15.70μg kg-1和ND~13.63μg kg-1,均值分别为22.02μg kg-1、4.04μg kg-1和2.15μg kg-1;进一步分析,已检出的样品中,NP在0~10μg kg-1的比重最大,NP1EO在4~6μg kg-1比重最大,NP2EO在1~2μg kg-1比重最大。NP的残留水平高于NP1EO和NP2EO,说明NP相对较难降解,更易在土壤中累积。     

小反刍兽疫N蛋白单克隆抗体的制备及竞争ELISA方法的建立

小反刍兽疫(PPR)是由小反刍兽疫病毒(PPRV)引起的一种危害严重的急性接触性传染病。为了检测血清中存在的抗PPRV的抗体,本研究利用纯化后的真核表达的PPRVN蛋白重组蛋白(rBacmid-PPRN)作为免疫原免疫BALB/c小鼠(Mus musculus),并使用原核表达的PPRVN蛋白重组蛋白(rpET-PPRN)作为间接ELISA检测抗原,共筛选得到8株抗PPRVN蛋白的单克隆抗体(mAb)。其中1D5单抗腹水效价达1∶106,分泌单抗亚类为IgG2b。以1D5作为竞争抗体、纯化后的rpET-PPRN蛋白作为包被抗原,建立了检测小反刍兽疫血清抗体的单抗竞争性ELISA(c-ELISA)方法。所建立的c-ELISA方法能够特异性的区分牛瘟阳性血清和小反刍兽疫阳性血清,并具有较高的灵敏度和特异性。应用建立c-ELISA检测方法检测共129份山羊(Capra hircus)血清样品,与标准c-ELISA试剂盒的符合率为96.9%。本研究成功地建立了可特异性检测动物血清中抗PPRV抗体的竞争性ELISA方法,对小反刍兽疫的诊断、疫苗免疫水平的监控及控制其流行具有重要意义。     

Predicting the Classes and Distribution of Salt-Affected Soils in Northwest Libya

Sodicity and salinity can adversely affect soil structure and are common constraints to plant growth in arid regions. Current remote sensing techniques cannot distinguish between the various classes of salt-affected soils. Field and laboratory measurements of salt-affected soils are time-consuming and expensive. Mapping of the salt-affected soils can be used in soil conservation planning to identify regions with different degrees of limitations. There is a need to use existing field and laboratory measurements to create maps of classes of salt-affected soils. The objectives of this study are to classify salt-affected soils, use existing field data to interpolate and validate geospatial predictions of the classes of salt-affected soils using Geographic Information Systems (GIS), and create maps showing the different classes and distribution of salt-affected soils. The classification framework for salt-affected soils is based on electrical conductivity (ECe), soil pH and the sodium adsorption ratio (SAR), and provides four degrees of limitations to salt-affected soils: slight (normal soils), moderate (saline soils), severe (sodic soils), and extreme (saline-sodic soils). Spatial interpolation of the field data from northwestern Libya was verified by cross-validation, and maps of the salt-affected soils in the region were created. The majority of soils in this region of Libya are normal (slight degree of limitation). Twenty percent of the topsoil is saline-sodic (extreme degree of limitation). Land use recommendations and rehabilitation strategies can be developed from such maps of salt-affected soil classes. The methodology followed in this study can be applied to other arid regions around the world, particularly in developing countries where budgetary constraints limit detailed field and laboratory measurements of sodicity and salinity.     

Amendment of hydroponic nutrient solution with humic acid and glutamic acid in tomato (Lycopersicon esculentum Mill.) culture

Abstract

Can humic acid (HA) and glutamic acid (GA), when added to tomato (Lycopersicon esculentum Mill. cv. ‘Hongyangli’) nutrient solution in a hydroponic system, improve growth? Tomato seedlings were grown in six nutrient solutions: (1) control (C), (2) C + 25 mg L^?1 HA (HA1); (3) C + 50 mg L^?1 HA (HA2); (4) C + 100 mg L^?1 GA; (5) HA1 + GA; (6) HA2 + GA. Various biochemical and physiological parameters were measured. HA increased photosynthesis rate and mesophyll conductance. HA did not significantly affect transpiration, stomatal conductance, titratable acidity, or antioxidant activity. In addition, GA improved protein and sugar content, mesophyll conductance and yield. The combination of HA and GA was more effective, especially with 50 mg L^?1 HA. The activity of superoxide dismutase (SOD) and peroxidases (POD) did not change in the presence of HA or GA. Malondialdehyde (MDA) content increased by 30% in HA2 together with GA. HA has a positive effect on tomato hydroponic growth when applied with GA. This expands the use of HA and GA for horticultural commodities in hydroponic systems.     

石灰性紫色土硝化作用及硝化微生物对不同氮源的响应

土壤中发生的硝化作用是对p H高度敏感的典型过程。本文采用室内恒温培养法,结合定量PCR和高通量测序,研究石灰性紫色土硝化作用以及氨氧化细菌(Ammonia-oxidizing bacteria,AOB)、氨氧化古菌(Ammonia-oxidizing archaea,AOA)、亚硝酸盐氧化细菌(Nitrite-oxidizing bacteria,NOB)的丰度与群落结构对不同氮源的响应。结果表明:不同氮源均刺激土壤硝化作用的发生,CO(NH2)2处理下的净硝化速率最大,约是CK处理的4.76倍,(NH_4)2SO4和NH_4Cl处理下的净硝化速率分别为N 3.88和3.34 mg kg-1d-1。相比于(NH_4)2SO4和CO(NH2)2处理,NH_4Cl处理降低了硝态氮的累积量,抑制了铵态氮的减少量。AOB amo A基因拷贝数在28 d培养过程中变化显著(p0.05),在(NH_4)2SO4和CO(NH2)2处理中呈先增长后降低趋势,在NH_4Cl处理中呈持续增长趋势;而AOA amo A基因拷贝数无显著变化(p0.05)。说明石灰性紫色土硝化作用的主要推动者是AOB,而不是AOA。在28 d培养过程中,亚硝酸盐氧化细菌占总微生物的比例高于氨氧化细菌和古菌,意味着石灰性紫色土中可能存在全程氨氧化微生物(Comammox)。高通量测序的结果表明:石灰性紫色土中AOB的优势种群为亚硝化螺菌Nitrosospira Cluster 3,AOA的优势种群是土壤古菌Group 1.1b,NOB的优势种群是硝化螺菌Nitrospira。     

Silicon Effect on Nutrient Acquisition of Peanut (Arachis hypogaea L.) Under Aluminum Stress

Aluminum (Al) toxicity represents one of the main yield-limiting factors for crops in acid soils. Silicon (Si) is known to increase tolerance in higher plants. This study was conducted to determine whether treatment with Si could improve nutrient uptake by peanut under Al stress. Peanut (Arachis hypogaea L. cv Zhonghua 4) was raised with or without Si (1.5 mM) in the growth chamber under 0 and toxic Al (0.3 mM) levels. Aluminum stress significantly decreased the root- and total-dry weight by 52.4% and 32.0%, respectively. The content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was significantly decreased, but that of Al increased markedly in shoots and roots after Al exposure at seedling, flower-needle, and pod-setting stage. Silicon alleviates Al toxicity in peanut plants in relation to Al distribution and allocation of tissue P, K, Ca, and Mg by favoring the partitioning of dry mass to roots.     

氮磷肥配合施用对桑树生长和桑叶产量的影响

在大田条件下研究了不同氮、磷肥施用水平对桑树生长和桑叶产量的影响。结果表明,氮磷肥适合用量配比能明显促进桑树生长,桑树每株枝条数、枝条长和枝条基部径围及桑叶百叶重均明显随氮肥和磷肥用量提高而增加。结果显示在氮肥用量为450kg/hm2时,N∶P2O5施用比例为3∶1时桑叶产量最高,在各种氮磷肥用量组合中,N450P150处理的桑叶产量比其他处理平均高5139kg/hm2,增产率达22.4%。试验结果表明,氮、磷肥对桑叶增产效果有互促作用,即高量氮肥施用需要有足够的磷肥施用才能充分发挥其增产效果,反之亦然。     

有限性灌溉对设施草莓产量及水分利用效率的影响

在日光温室环境及盆栽条件下,通过与全灌(FI)比较,研究了亏缺灌溉(DI)及分根交替灌溉(PRD)对草莓产量和灌水利用效率(IWUE)的影响.试验从开花期开始到果实成熟期结束.共分5个处理,全灌(FI);分根灌溉PRD分2个处理水平,即PRD1和PRD2;限制灌溉DI也分两个处理水平,即D11和D12.与F1处理相比,DI1和DI2处理的叶水势和气孔导度明显偏低,单株叶面积、鲜果重、平均单果重也显著低于FI处理.但水分利用效率却比FI处理的高(分别高15.8%和29.3%);PRD1处理的叶水势与FI处理的相当.且高于其它处理,而气孔导度比FI,DI1和D12处理的明显降低,与PRD2处理的相近.PRD1处理的鲜果重、平均单果重与FI处理的相当,比DI1,DI2和PRD2处理的显著提高;与FI处理相比,DI1,DI2,PRD1和PRD2处理分别节水31.5%,50.0%,31.5%和50.0%,水分利用效率分别提高了15.8%,29.3%,44.4%和84.4%,从草莓产量和水分利用效率各指标可以看出,PRD1处理比DI1,DI2和PRD2处理表现出明显的优势,其综合效益最佳.     

新发PDCoV和TGEV双重RT-PCR检测方法的建立及初步应用

猪Delta冠状病毒(Porcine deltacoronavirus,PDCoV)是一种新发现的冠状病毒,临床上主要引起感染仔猪出现水样腹泻、呕吐和脱水等症状,和猪传染性胃肠炎病毒(Porcine transmissible gastroenteritis virus,TGEV)感染引起的临床症状极为类似,且临床上PDCoV和TGEV混合感染时有发生,单靠临床诊断很难区分两种疾病,因此建立同时检测且区分PDCoV和TGEV的检测方法具有重要的临床意义.本研究根据GenBank中收录的PDCoVN基因和TGEVN基因序列设计了2对引物,在同一反应体系中同时扩增PDCoV的N基因片段和TGEV的N基因片段,通过对RT-PCR反应条件的优化,建立了同时检测PDCoV和TGEV的双重RT-PCR方法,并对该方法进行了特异性、灵敏性和重复性研究.结果显示,所建立的双重RT-PCR对PDCoV和TGEV的最低检测量分别是3.14×102 copies/μL和3.68× 103 copies/μL,利用该双重RT-PCR方法对猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)、猪博卡病毒(Porcinebocavirus,PBoV)、猪繁殖与呼吸综合征病毒(Porcine respiratory and reproductive syndrome virus,PRRSV)和猪伪狂犬病毒(P.pseudorabiesvirus,PRV)的扩增结果均为阴性,显示出较好的特异性.为了解所建立的双重RT-PCR方法的临床应用效果,对252份临床样品进行了检测.结果表明,双重RT-PCR检出PDCoV阳性样品31份(阳性率为12.30％),TGEV阳性样品12份(阳性率为4.76％),同时感染PDCoV和TGEV的阳性样品2份(阳性率为0.79％),且检测结果与单一PDCoV和TGEV RT-PCR相符.因此,本研究所建立的双重RT-PCR方法可用于PDCoV和TGEV的临床检测,为进一步研究PDCoV和TGEV的临床鉴别诊断和流行病学调查提供了理论依据和技术支持.     

不同利用方式下土壤有机质和全磷的可见近红外高光谱反演

以太湖流域直湖港小流域稻田、桃园和菜地的土壤样本为研究对象,研究了不同光谱建模方法和土地利用方式对土壤有机质和全磷高光谱反演的影响。结果表明:(1)偏最小二乘回归分析(Partial least squarer egression,PLSR)模型的建模和预测精度较高且稳定;人工神经网络中广义回归神经网络(Generalized regression neural network,GRNN)网络预测精度较高但易出现过拟合现象,反向传播神经网络(Back propagation neural network,BPNN)网络比较稳健但精度略低;偏最小二乘与人工神经网络相结合则可综合两者优点,改善复杂样本下的预测精度。(2)土壤有机质的光谱反演结果优于全磷。3种土地利用方式中,稻田的预测效果总体优于桃园和菜地。在当前研究区域内土地利用方式对土壤有机质光谱反演影响不大,但对全磷反演影响较大。今后利用光谱对土壤全磷反演时需分土地利用方式对模型进行校准。     

外源胡敏酸对土壤有机质组分变化的影响及其与茶树铅有效性的关系

盆栽试验分析了胡敏酸输入土壤6个月后茶树根际和非根际土壤有机质SOM及其组分,包括水溶性物质WSS、富啡酸FA、胡敏酸HA以及土壤微生物生物量SMB的变化,并对不同土壤有机质组分碳含量和茶树不同组织铅含量作了相关性分析。外源胡敏酸设置3个浓度水平（0、300、600 mg kg-1）,铅设置2个浓度水平（0、300 mg kg-1）,试验共有6个处理。茶苗置于温室培养,6个月后分新叶、老叶、新茎、老茎、根收获。结果表明：根际并非总是富含有机质,未加铅处理根际SOM含量低于非根际;而加铅处理根际SOM含量高于非根际。HA加入土壤能够显著增加根际和非根际SOM和SMB的含量,但是加铅处理和不加铅处理增加幅度不同。高浓度HA显著增加了根际FA的含量,可能是HA部分裂解所致。非根际有机质各组分与茶树铅含量无显著相关关系;根际SOM、HA和茶树不同组织铅含量没有显著相关关系。根际WSS、FA与茶树嫩叶、老叶、嫩茎、老茎以及根部铅含量均存在显著或极显著正相关关系;而根际SMB与茶树各个组织铅含量存在显著负相关关系。总之,胡敏酸施入土壤改变了土壤有机质及其各个组分的含量,而根际某些土壤有机质组分的改变又显著影响了茶树不同组织铅的吸收和分布。     

N-甲基-D-天冬氨酸(NMDA)对大鼠下丘脑生长抑素分泌及其mRNA表达的影响

N-甲基-D-天冬氨酸(NMDA)是动物机体内存在的一种天然氨基酸衍生物,参与下丘脑-垂体生长轴的调控分泌作用。本实验选用SD大鼠(Rattus norvegicus)下丘脑,采用神经细胞体外培养模型来研究NMDA对下丘脑合成和分泌生长抑素(SS)的影响。结果表明,适量浓度的NMDA可显著促进下丘脑神经细胞SS的分泌及其mRNA的表达,明显提高细胞内的Ca2+水平,并使cAMP浓度降低,表明SS基因表达和分泌的增加可能主要是通过Ca2+和环腺苷酸(cAMP)共同介导实现的。     

近红外光谱法快速测定土壤碱解氮、速效磷和速效钾含量

运用偏最小二乘法(PLS)和人工神经网络(ANN)方法分别建立了0.9 mm筛分风干黑土土壤碱解氮、速效磷和速效钾含量预测的近红外光谱(NIRS)分析模型。使用偏最小二乘算法建立的碱解氮、速效磷和速效钾校正模型的决定系数R²分别为0.9520、0.8714和0.7300，平均相对误差分别为3.42%、13.40%和7.40%。人工神经网络方法建立的碱解氮、速效磷和速效钾校正模型的决定系数分别为0.9563、0.9493和0.9522，相对误差分别为2.67%、6.48%和2.27%，测试集仿真的相对误差分别为5.44%、16.65%和7.87%。结果表明，人工神经网络方法所建立的校正模型均优于偏最小二乘法所建模型；用近红外光谱分析法预测土壤碱解氮含量是可行的，而速效磷、速效钾模型的测试集样品仿真的相对误差较大，其预测可行性还需做进一步研究。     

Influence of Salicylic Acid and Jasmonic Acid on Wheat Under Drought Stress

Salicylic acid and jasmonic acid play an important role in plants coping with abiotic stresses. An experiment was conducted to examine the effect of salicylic acid and jasmonic acid on wheat under drought. Seeds were primed with jasmonic acid (100µM) and salicylic acid (10 Mm). Water stress was applied by withholding water and each treatment was replicated three times with a factorial block design. Application of Salicylic acid and Jasmonic acid mitigated drought effects in wheat. Results revealed that 100µM Jasmonic acid was more effective than 10 mM SA. Drought decreased germination by 26%, whereas application of Jasmonic acid and Salicylic acid ameliorated stress with the increase of germination by 27% and 21%, respectively. An increase in the shoot length of 23% and 20% was observed with Jasmonic acid and Salicylic acid, under drought conditions. The increase in water potential was 60% and 47% with JA and SA while the increase in proline and soluble sugar was 14% and 25% respectively. The application of Jasmonic acid and Salicylic acid has a potential to enhance the growth of wheat plants under drought.     

Influence of PGPR-enriched liquid organic fertilizers on the growth and nutrients uptake of maize under drought condition in calcareous soil

In order to study the effect of water deficit stress (WDS), plant growth promoting rhizobacteria (PGPR)-enriched and non-enriched vermicompost tea(VT) and vermiwash(V) on the growth and nutrients uptakes of maize, a greenhouse experiment was conducted. The two-factor experiment was set up in a completely randomized design with three replications. The factors included: 1) liquid organic fertilizers (LOFs) with five levels (control, VT, V, vermicompost tea enriched with bacterium (VTB) and vermiwash enriched with bacterium (VB)) and 2) WDS with three levels (Field Capacity (FC), 80% FC and 60% FC(. At each irrigation interval, the volume of the used LOFs was equivalent to 60% of the volume of water required for 60% FC. At 60% FC, shoot dry matter (SDW), shoot N, P, Zn, Cu, and Fe uptake significantly decreased compared with those of FC and 80% FC, whereas shoot K uptake significantly increased. At all WDS levels, application of LOFs led to increase in SDW and shoot nutrients uptake. The highest amount of studied traits was obtained in VTB and VT treatments. Generally, VT treatments were more effective than V. Furthermore, PGPR-enriched LOFs were more effective than non-enriched ones. Application of LOFs may be considered as a practical approach for amplifying drought tolerance and reducing the risk of water scarcity in maize cultivation.     

Relationships between ammonia oxidizers and N2O and CH4 fluxes in agricultural fields with different soil types

Nitrous oxide (N₂O) is a greenhouse gas that contributes to the destruction of stratospheric ozone, and agricultural soil is an important source of N₂O. Aerobic soils are sinks for atmospheric methane (CH₄), a greenhouse gas. Ammonia monooxygenase (AMO) can oxidize CH₄, but CH₄ is mostly oxidized by methane monooxygenase (MMO), and CH₄ oxidation by AMO is generally negligible in the soil. We monitored the N₂O and CH₄ fluxes after urea application in fields containing different soils using an automated sampling system to determine the effects of environmental and microbial factors on the N₂O and CH₄ fluxes. The soil types were Low-humic Andosol (Gleyic Haplic Andosol), yellow soil (Gleyic Haplic Alisol) and gray lowland soil (Entric Fluvisol). Cumulative N₂O emissions from the yellow soil were higher than those from other soil types, although the difference was not significant. The CH₄ uptake level by Andosol was one order of magnitude higher than that by other soils. There were significant relationships between the ammonia oxidation potential, AOB and AOA amoA copy numbers, and the CH₄ uptake. In contrast, the gene copy numbers of methane-oxidizing bacteria (MOB) pmoA were below the detection limit. Our results suggested that the AMOs of AOB and AOA may have more important roles than those previously considered during CH₄ oxidation in agricultural soils treated with N fertilizers.     

基于不同植被指数的TRMM数据降尺度及误差校正研究

[目的]对不同时间尺度的热带测雨卫星(TRMM)数据进行空间降尺度及误差校正研究,为华中地区洪涝灾害监测等提供科学参考.[方法]主要借助增强型植被指数(EVI)和归一化植被指数(NDVI)分别运用地理加权回归(GWR)模型实现2001-2019年华中地区TRMM数据的空间降尺度,并结合地理差异分析(GDA)和地理比率分...     

Trace Metal Contamination During Grinding of Plant Samples

Inductively coupled plasma-mass spectroscopic (ICP-MS) analysis of leaves from 22 cabbage crops in the Sa P? and B?c Hà districts of Láo Cai Province, North-Western Vi?t Nam, revealed unexpectedly high concentrations of chromium (Cr) and nickel (Ni). The concentrations were strongly linearly related (r² = 0.94), indicating sample contamination during grinding through a stainless-steel hammer mill. We tested this hypothesis in two ways. First, brown rice ground through the same mill was contaminated not only by Cr and Ni, but also cobalt (Co), iron (Fe) and molybdenum (Mo). Second, scanning electron microscopy/energy dispersive analysis of x-rays (SEM/EDS) of the ground samples revealed small fragments with co-located Fe, Cr and Ni, consistent with stainless steel wear fragments. Other grinders may perform differently and we suggest that quality assurance protocols for trace metal analysis of plants should include testing for grinder wear metals. Lastly, brown rice appears to be convenient for investigating contamination of plant tissues during grinding.