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1.
AA3型连续流动分析仪（CFA）同时测定橡胶叶全氮、全磷、全钾的方法研究 总被引：10，自引：0，他引：10
通过对AA3型连续流动分析仪所附试剂配制等方法的改进,研究AA3同时测定橡胶叶片氮、磷、钾的方法。结果表明,氮、磷、钾混合标准曲线相关系数均达0.999 9以上;氮、磷变异系数均小于0.5%(n=10),当钾浓度相当于标准曲线中间浓度范围时(即6～10 mg/L),变异系数为0.97%～1.13%,重现性良好;氮、磷、钾加标回收率分别为99.7%～101.1%、99.3%～100.7%、98.4%～102.8%,待测液中氮、磷、钾检出限分别为0.019、0.004、0.072 mg/L。橡胶叶片氮、磷、钾测定结果与常规法相比无显著差异。该方法用于橡胶叶片H2SO4-H2O2消煮后氮、磷、钾同时测定,快速高效,一天半可测300个样品待测液,提高工效10多倍。 相似文献
2.
玉米叶片总蛋白提取和双向电泳技术的改进 总被引：7，自引：1，他引：7
针对植物组织蛋白质含量较低,有些组分在两性电解质中的溶解性低以及绿色组织中的色素、酚类、醌类等次生代谢产物干扰蛋白质双向电泳分离效果的问题,以玉米苗期叶片为材料,对蛋白质裂解液、蛋白质浓度测定体系、等电聚集电泳电压和时间、聚丙烯酰胺凝胶浓度等技术参数做了改进。用改进的裂解液提取的蛋白质样品浓度达3.8μg/μL,比改进前提高90%。通过在浓度测定体系中加入HCl并用裂解液代替超纯水配制标准蛋白,可得到线性更好的蛋白浓度测定标准曲线。用改进后的等电点聚焦电泳的电压、时间和聚丙烯酰胺凝胶浓度,可从玉米叶片总蛋白质样品中分离出963个清晰的蛋白点,在其他条件相同的情况下,比改进前的技术体系多分离出429个蛋白点。 相似文献
3.
施氮和大气CO2浓度升高对春小麦拔节期光合作用的影响 总被引：1，自引：0，他引：1
为明确高大气CO2浓度下小麦叶片光合作用的适应机制及氮素的调控作用,利用开顶式气室,通过盆栽试验,测定和分析了不同大气CO2浓度和施氮量下小麦拔节期叶片的光合参数、叶绿素含量等指标.结果表明,高大气CO2浓度(760 μmol·mol-1)处理的小麦叶片的叶绿素含量、光合速率(Pn)、气孔导度(G5)和蒸腾速率(Tr)均随着施氮水平的升高而升高,平均增幅分别为31.6%、69.6%和57.6%,而胞间CO2浓度(Ci)和水分利用效率(WUE)随施氮水平的升高而呈先下降后上升的趋势.高大气CO2浓度下小麦叶片Pn、Ci和WUE显著高于正常CO2浓度(400 μmol·mol-1)处理,平均增幅分别为36.8%、74.O%和102.7%.在400 μmol·mol-1 CO2浓度下测定时,与正常大气CO2浓度下生长的小麦相比,高大气CO2浓度下生长的小麦拔节期叶片Pn在高施氮水平(0.2 g N·kg-1土)下未发生下调,而在低、中施氮水平(0和0.1 g N·kg-1土)下叶片Pn明显降低.因此,高大气CO2浓度下施氮可显著提高小麦叶片的Pn和WUE,且充分供氮可使叶片不发生光合适应现象,这可能与较高的施氮水平提高了高大气CO2浓度下小麦叶片的叶绿素含量有关. 相似文献
4.
大豆植株全氮磷钾含量变化分析 总被引：14，自引：3，他引：14
对东北三省6个大豆品种,在苗期、分枝期、花期、结荚期、鼓粒期和成熟期,测定叶片、叶柄、茎杆、荚的全氮(N)、全磷(P_2O_5)、全钾(K_2O)含量,并进行显著性测定,相关和通径分析。结果表明:不同品种间全氮含量差异接近显著;全磷含量差异不明显,可能由于施用磷酸二铵做种肥所致;全钾含量差异显著。不同生育阶段全氮,全磷含量变化极显著,F_N=175.53F_P=8.238(F_(0.01)=5.42);全钾变化平稳。植株不同器官全氮含量以叶片(4.644％)>荚(4.408％)>茎杆(1.780％)>叶柄(1.179％);全磷含量荚(0.997％)>叶片(0.856％)>茎杆(0.610％)>叶柄(0.489％);全钾含量荚(2.010％)<茎杆(1.881％)>叶柄(1.788％)>叶片(1.270％)。大豆全氮、磷、钾含量间有明显的相互作用。全氮与全磷,全氮与全钾呈显著正相关,r_(N、P)=0.539,r_(N、K)=0.6003,全磷与全钾直接作用不明显,但通过全氮的间接作用明显。 相似文献
5.
施氮量对茶树生长及叶片光合特性的影响 总被引：1，自引：0，他引：1
采用水泥池培育的方法,研究了不同氮肥施用量对茶树生长和叶片光合特性的影响。试验设置4个施氮水平,分别为0kg N/hm2（CK）、112.5 kg N/hm2（N1）、225 kg N/hm2（N2）和450 kg N/hm2（N3）。结果表明：施氮显著促进茶树生长,施氮处理茶叶产量比CK显著提高116.98%～141.51%（P〈0.05）,但施氮处理间差异不显著（P〉0.05）;施氮处理茶树叶片叶绿素总量提高30.56%～72.67%,类胡萝卜素含量降低13.37%～29.74%,并与CK差异显著（P〈0.05）;施氮处理茶树叶片净光合速率比CK显著提高14.88%～17.26%（P〈0.05）,但施氮处理间差异不显著（P〉0.05）;氮肥施用提高茶树叶片气孔导度、蒸腾速率和水分利用效率。适量的施氮可提高茶树叶片叶绿素含量、提高光合速率,促进茶树生长和茶叶产量提高;但随着氮肥施用量的增加,单位氮肥对茶树生长的促进效应降低。 相似文献
6.
为了解施用氮肥对受铜毒害小麦的生长发育的调控效应，在不同质量浓度的Cu^2＋溶液浸种后,测定了不同施氮条件下小麦种子萌发过程中淀粉酶与POD的活性、脯氨酸与叶绿素的含量。结果表明,施N肥有利于铜胁迫条件下小麦叶片中叶绿素的合成。在低质量浓度Cu^2＋（≤60mg／L）胁迫务件下，施N肥有利于增强小麦淀粉酶的活性，抑制植物体内过氧化物的产生，促进小麦种子的萌发和幼苗生长；高质量浓度Cu^2＋（〉60mg／L）胁迫条件下,施N肥降低小麦淀粉酶活性．促使小麦体内过氧化物大量产生，抑制小麦种子的萌发和幼苗生长。 相似文献
7.
为明确湖南稻作烟区植烟土壤全氮含量和空间分布及主要影响因素,采用地统计学和分组回归方法研究了土壤全氮含量区域和空间分布及特征,并分析了土壤耕层厚度、海拔高度、土壤pH值和有机质含量对土壤全氮含量的影响。结果表明：湖南稻作烟区植烟土壤全氮含量丰富,其平均值为2.37 g/kg,变幅为0.62～5.26 g/kg,适宜样本(全氮含量为1.00～2.00 g/kg)占32.02%,有21个县区土壤全氮含量>2.00 g/kg,土壤全氮含量有从东南向西北递减的分布趋势。耕层厚度越深,土壤全氮含量越低;土壤全氮含量随海拔升高,达到峰值(高度为150～250 m)后下降;植烟土壤的全氮含量与土壤pH、有机质呈正相关。 相似文献
8.
CO2浓度升高条件下水稻蒸腾与N吸收的关系 总被引：2，自引：2，他引：0
利用FACE（Free Air Carbon Dioxide Enrichment）平台技术,用水培试验研究了低氮（14 mg/L）和高氮（28 mg/L）水平下,大气CO2浓度升高条件下水稻蒸腾与N吸收速率的相关关系。结果表明,在CO2浓度升高条件下,水稻生物量增加了36%（低N）和29%（高N）;总吸N量也增加达7%（低N） 和5%（高N）;而总蒸腾量减少28%（低N）和10%（高N）。由于促进更多分蘖的发生,高CO2浓度使分蘖期水稻平均N吸收速率提高了31%～156%（低N）和19%～87%（高N）,在其他时期无明显影响;而高CO2浓度对水稻平均蒸腾速率的影响主要表现在抽穗到灌浆末期。在对照条件下,平均蒸腾速率和平均N吸收速率呈显著正相关;但在CO2浓度升高条件下,两者相关关系不显著。说明人们所推测的“蒸腾效应”——高CO2浓度条件下降低了的蒸腾作用并非影响水稻N吸收的关键因素。 相似文献
9.
氮肥施用方式对土壤有机质与氮素含量的影响 总被引：3，自引：0，他引：3
在秸秆还田条件下,研究了氮肥施用方式对白浆土有机质与氮素时空动态的影响.结果表明:在秸秆还田条件下,白浆土0～20 cm土壤有机质含量随生育进程呈增加的趋势,至收获期达到最大值,20～30 cm土壤于R4期达到最大值;白浆土全氮含量随生育进程呈单峰曲线,于R2～R4期达到最大值;碱解氮含量随生育进程呈单峰曲线,0～20 cm土壤于R5期、20～30 cm土壤于R2期达最大值.种肥施氮增加了0～20 cm土壤有机质含量,追施氮肥使10～30 cm土壤有机质含量增加;种肥施氮增加了R2期以前土壤全氮含量,追施氮肥对土壤全氮含量影响不明显;种肥施氮使20～30 cm土壤碱解氮含量降低,对0～20 cm土壤影响不大,追施氮肥使土壤碱解氮含量增加.白浆土有机质含量与全氮含量、有机质含量与碱解氮含量、碱解氮含量与全氮含量均呈极显著正相关. 相似文献
10.
施用生物质炭对酸性茶园土壤氨挥发的影响 总被引：2，自引：0，他引：2
氨挥发是土壤氮素损失的主要因素之一。通过田间试验,研究了施用生物质炭对酸性茶园土壤理化性质及氨挥发的影响,以期为评价生物质炭在茶园土壤中的应用提供科学数据。试验设不施氮肥(对照CK)、单施氮肥(B0N1,225 kg·hm-2)、施8 t·hm-2生物质炭基础上增施氮肥(B1N1)、施16 t·hm-2生物质炭基础上增施氮肥(B2N1)4个处理,施氮量春季追肥、秋季追肥和冬季基肥比例为3︰3︰4,进行了为期1年的观测。结果表明,与B0N1处理相比,B1N1和B2N1处理显著提高了土壤p H值和有机碳含量(P0.05),显著降低了土壤容重(P0.05),全氮量变化不显著(P0.05);与B0N1处理相比,B1N1和B2N1处理土壤铵态氮平均含量降低了5.34%~12.59%,硝态氮平均含量增加了11.02%~36.54%,促进硝化作用。酸性茶园土壤氨挥发量为13.01~40.95 kg·hm-2,氨挥发损失率为7.29%~12.42%,冬季基肥期氨挥发损失量最大;施氮显著增加土壤氨挥发量(P0.05),增施生物质炭则显著降低了氨挥发量(P0.05),降幅为26.25%~28.21%。土壤铵态氮浓度是影响氨挥发的最主要因素,施用生物质炭降低了土壤铵态氮浓度,从而抑制了氨挥发。 相似文献
11.
Joseph E. Laferriere Charles W. Weber Edwin A. Kohlhepp 《Plant foods for human nutrition (Dordrecht, Netherlands)》1991,41(3):277-282
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. 相似文献
12.
13.
Lakshman Lal 《Potato Research》1987,30(2):329-334
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. 相似文献
14.
《Journal of Crop Improvement》2013,27(2):81-114
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. 相似文献
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16.
Tatiana G. Polotow Sandra C. Poppe Cristina V. Vardaris Douglas Ganini Maísa Guariroba Rita Mattei Elaine Hatanaka Maria F. Martins Eduardo F. Bondan Marcelo P. Barros 《Marine drugs》2015,13(10):6117-6137
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. 相似文献
17.
Youna Hemery Ulla Holopainen Anna-Maija Lampi Pekka Lehtinen Tanja Nurmi Vieno Piironen Minnamari Edelmann Xavier Rouau 《Journal of Cereal Science》2011
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. 相似文献
18.
Alexander N. Shikov Elena V. Flisyuk Ekaterina D. Obluchinskaya Olga N. Pozharitskaya 《Marine drugs》2020,18(11)
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future. 相似文献
19.
M. I. Siri P. Villanueva M. J. Pianzzola L. Franco Fraguas G. Galván M. Acosta F. Ferreira 《Potato Research》2004,47(3-4):127-138
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. 相似文献
20.
Tovar LR Olivos M Gutierrez ME 《Plant foods for human nutrition (Dordrecht, Netherlands)》2008,63(4):189-194
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. 相似文献