高效液相色谱法测定不同品种番木瓜果实中维生素C含量

通过优化实验条件,使用高效液相色谱法对海南省种植范围较广的几种番木瓜(中白、大青、小青)维生素C(Vc)含量进行测定。选取3个番木瓜品种成熟果实,通过HPLC方法测定Vc的标准溶液线性、精密度、回收率等,并比较该法与国标方法的重复性。结果显示,获得线性回归方程y＝35.41x－4.16(r＝0.999),Vc在 60～300 μg/mL 的浓度范围线性关系良好,方法回收率为98.56%～103.21%,精密度RSD为0.69%;测得中白、大青、小青果肉Vc含量分别为49.12、43.38、46.31 mg/hg。HPLC法结果重现性RSD为0.68%;2,6-二氯靛酚滴定法结果重现性RSD为5.45%,表明HPLC法是检测番木瓜等深颜色水果Vc含量可靠的方法。     

分散固相萃取-反相高效液相色谱法测定蔬菜、水果中10种氨基甲酸酯类农药残留

建立分散固相萃取-反相高效液相色谱同时测定蔬菜和水果中10种氨基甲酸酯类农药(涕灭威，涕灭威砜，涕灭威亚砜，克百威，3-羟基克百威，灭多威，甲萘威，异丙威，速灭威，仲丁威)残留的分析方法。样品经乙腈提取，PSA分散固相萃取净化，液相色谱柱后衍生分离，荧光检测(λex＝330 nm, λem＝465 nm)测定，外标法定量。10种农药在0.005～0.50 mg/L范围内线性关系良好；检出限在0.004～0.008 mg/L；平均加标回收率在75.6%～112.3%，相对标准偏差(RSD)在 0.8%～10.2%。该方法具有快速、灵敏、准确、重现性好以及操作简单等特点，适合日常大批量蔬菜和水果样品中10种氨基甲酸酯类农药残留的测定。     

HPLC法测定人参脂溶性成分中亚油酸含量

建立HPLC法测定人参脂溶性成分中亚油酸的含量。采用Agilent TC C18色谱柱(4.6×250 mm,5μm),以乙腈-0.1%磷酸溶液(65∶35,v∶v)为流动相,检测波长为203 nm,流速为1.0 mL/min,进样体积为10μL,柱温为25℃。结果亚油酸浓度在5.25~525μg/mL范围内与峰面积呈良好的线性关系(r=0.9997),平均回收率为98.59%,RSD值为1.54%。表明该方法操作简单、稳定可靠,适用于人参脂溶性成分中亚油酸的含量测定,为人参脂溶性成分的研究提供依据。     

木薯叶黄酮醇检测方法优化及其含量比较分析

木薯叶富含丰富的黄酮醇类物质，高效的提取和分析方法可为获取木薯叶黄酮醇提供至关重要的评价技术。本研究旨在优化木薯叶中4种黄酮醇物质（杨梅苷、芦丁、烟花苷和水仙苷）的提取和检测方法，以及分析不同木薯品种、采收期和成熟度对这些黄酮醇含量的影响。结果表明：使用50%乙醇水溶液，料液比为1∶50(g/mL)，超声提取温度50℃，超声提取时间60 min可有效提取木薯叶中的4种黄酮醇；不同的C18色谱柱配备HPLC-DAD能有效分离木薯叶中的4种黄酮醇；方法验证结果显示，4种黄酮醇在一定浓度范围内线性相关性良好，R2分别达到0.9999、0.9999、0.9999和0.9998；检出限在6.0～10.0 mg/kg之间；定量限在20.0～32.0 mg/kg之间；检测方法系统适应性较好，保留时间和峰面积变化相对标准偏差（RSD）均小于1%；样品日内、日间和月内稳定性较好，含量变化RSD在0.44%～3.57%之间，平均加标回收率在92.68%～109.14%之间，RSD均小于6.0%。利用建立的提取和分析方法，分析了30个木薯种质中4种黄酮醇含量，芦丁和烟花苷含量占4种黄酮醇总量的93.50%～...     

超快速高效液相色谱法测定普通白菜中16种氨基甲酸酯类农药残留

研究应用超快速高效液相色谱仪柱后衍生荧光检测器同时测定普通白菜中16种氨基甲酸酯类农药残留。对流动相组成、波长选择、梯度洗脱等条件进行比较研究,建立了样品经乙腈提取,SPE-NH2固相萃取柱净化,液相色谱柱后衍生分离,荧光检测(λex＝339 nm, λem＝445 nm)测定,外标法定量的检测方法。研究表明：基于液相色谱荧光检测条件,16种农药残留在0.025～1.0 mg/L浓度范围内线性关系良好;检出限0.002～0.010 mg/L;平均加标回收率73.0%～103.0%,相对标准偏差(RSD)1.5%～8.8%。该研究确定的方法具有检测范围广、快速、灵敏、准确、重现性好、易推广等特点。     

15种茶叶中茶碱含量的测定

运用高效液相色谱仪采用梯度洗脱法测定不同茶叶中茶碱的含量。结果 15种茶中茶碱含量在0.19-1.27mg·g~(-1)范围内,含量最高是工夫红茶,其次是茉莉花茶,最低是乌龙茶。结论:不同茶叶其茶碱的含量不一。本测定方法在茶碱质量浓度在1.13~113μg·m L~(-1)范围内有良好的线性关系;加样平均回收率(n=9)为100.71%,RSD为1.93%。     

大豆生育期间尿囊素和尿囊酸的分配和运输

以大豆品种WellⅡ为试材,在营养生长时期(V)、花期(R_2)、结荚初期(R_3)、中期(R_4)和后期(R_6)五个生育时期,每一生育期又分为顶芽、叶柄、叶源、茎、荚、根等十八个部位,对尿囊素和尿囊酸含量进行详细研究。其结果指出,尿囊素和尿囊酸由根部经木质部向顶端运输。尿囊素和尿囊酸在各生育期和植株各部位均有分配,但其含量各异,一般出现在茎、荚皮和大豆种皮中,但在种子胚中没有观察到尿囊素和尿囊酸的存在。在各生育期中,尿囊素和尿囊酸高峰出现在植株上的部位各异。     

刺五加总黄酮含量的分析

目的:测定刺五加总黄酮含量。方法:采用三氯化铝—醋酸钠比色法,测定总黄酮的含量。结果:刺五加总黄酮含量在5.8mg～34.8mg范围内,芦丁mg数与吸光度值线性关系良好,平均回收率为100.63%,RSD=1.05%,R2=0.9995。刺五加不同部位总黄酮含量分别为:根皮18.96%,茎皮(1年生)10.29%,茎皮(2年生)9.08%,茎皮(3年生)8.3%,茎皮(4年生)8.27%,叶柄(8月25日)5.43%,叶柄(9月3日)5.14%。结论:刺五加不同部位总黄酮的含量有很大差异,茎皮中总黄酮的含量随着年限的增加而降低。     

HPLC法测定加味天麻胶囊含量的方法研究

目的建立加味天麻胶囊含量的高效液相色谱测定法。方法采用C18色谱柱,流动相为乙腈-0.05%磷酸溶液(3:97),流速:1.0ml/min,检测波长为220nm,进样量为10μl。结果在该色谱条件下,在浓度2~19.8μg/ml范围内线性关系良好,r=0.9997,重复性RSD=0.46%,平均回收率为98.6%(RSD=0.41%)。结论本法灵敏、简便、准确、重复性好,能有效控制加味天麻胶囊的含量。     

市售红参质量评价

目的评价市售红参的质量。方法采用比色法测定,检测波长为544nm。结果比色法测定在20~120μg(r=0.9993)范围内线性关系良好,平均回收率为101.3%,RSD=2.45%(n=5)。峰泉红参中人参总皂苷含量最高,其次为华瑞红参。结论该方法操作简便,稳定性和重现性好,可用于红参中人参总皂苷含量的测定。所测5种市售红参中有4种人参总皂苷含量大于2.5%。仅有一种人参总皂苷含量略低于2.5%。     

Allelopathy in Agroecosystems in Spain

Summary

This paper reviews the effects of allelopathic interactions in agroecosystems in Spain on plant physiological activity and their ecological advantages. The phenological stage of growth of donor plants and the effective allelochemicals in the soil solution while studying the role of phenolic compounds were highlighting. Finally possible future prospects and conclusions regarding weed control by allelochemi-cals under integrated crop management strategies are discussed.     

Factors in the Reduction in Grain Number in Winter Wheat by Early-Sowing in Yamaguchi

Abstract

Grain number per spike of wheat is lower in early sowing than in the conventional standard cultivation in Yamaguchi, Prefecture, Japan. Components of the grain number per spike in five cultivars were analyzed with respect to temperature during the spike development period throughout three growing seasons 2001/2002, 2002/2003 and 2003/2004 to find the cause of the problem of early sowing cultivation. The plants sown in early-October and late-November were called the early sown group and the standard group, respectively, in the following. Three of the five cultivars, Hokushin, Akitakko and Nanbukomugi, showed a strong winter habit, which requires very cold temperatures for spike differentiation. The other two cultivars, Iwainodaichi and Airakomugi, had a moderate winter habit. Grain number per spike and grain yield were decreased by early-sowing (compare with the standard group) in almost all cultivars throughout the three growing seasons. The three cultivars which had a strong winter habit had fewer spikelets per spike in the early-sown group than in the standard group. The other two cultivars which had a moderate winter habit had fewer grains per spikelet in the early-sown group. The higher the temperature during the spikelet formation phase, which is from flag leaf initiation to terminal spikelet initiation, the higher the number of spikelets per spike in the standard group. The spikelet number per spike in the early-sown group increased with the increase in productive tillers under fertile conditions. Such conditions also increased the grain number per spike.     

我国干热区甘蔗抗旱植蔗主要问题研讨

我国干热蔗区是我国甘蔗糖业的重要生产基地,蔗区光热资源丰富,唯降水分布不均成为植蔗生产的主要限制因子;根据蔗区植蔗特点和甘蔗需水规律,苗期抗旱是干热蔗区抗旱植蔗的关键,保证较多的总苗数和足够的生长量是苗期抗旱植蔗需解决的关键技术难题,制定相应的苗期抗旱植蔗栽培技术措施是解决该难题的重要保障;该观点为我国干热蔗区植蔗生产、甘蔗引育种提供理论和技术支持。     

2009年中国稻米市场分析及2010年展望

以翔实的资料对2009年中国稻米生产、消费、进出口、供求平衡、库存、价格走势、购销政策和国际稻米供求等情况进行了全面地分析,对影响2010年稻米市场价格走势的各种因素进行了深入研究,并在此基础上对2010年我国稻米市场价格走势进行了预测,结论是我国稻米价格仍呈上行趋势。     

Diurnal changes in net photosynthetic rate in potato in two environments

Summary Diurnal changes in net photosynthetic rate were measured in a furrow-irrigated potato crop and in a riverbed crop where the water table was always maintained at 20–28 cm from the soil surface. In the irrigated crop, the photosynthetic rate during mid-afternoon was about half the peak rate observed at noon. This reduction was accompanied by a near tripling of stomatal resistance, a 45% reduction in transpiration, and a 5-fold increase in the difference between leaf and air temperatures. No such changes were observed in the riverbed crop where the photosynthetic rate remained nearly constant at about 0.9 mg m⁻² s⁻¹ between 9 a.m. and 4 p.m. Tuber yield in the riverbed crop was about 30% higher than in the irrigated crop.     

棉花体细胞无性系变异的研究进展

体细胞无性系变异是一种重要的细胞工程育种技术,其应用于棉花育种的前提是建立高效的组织培养诱导再生植株体系.本文简要综述了棉花离体诱导植株再生研究的现状,重点讨论了棉花体细胞无性系变异的表现、利用方法及机理,提出了当前研究存在的问题并对今后的研究进行了展望.     

Changes in daily rainfall characteristics in major rice producing provinces in Laos

In order to find the changes in rainfall characteristics and to examine the flood damage to lowland rice, a statistical analysis was carried out on the 40-year daily rainfall record at four rainfall stations (Thangon, Paksane, Seno, and Pakse) in Laos. The rainfall record was divided into two periods of 20 years each. The results of this analysis revealed the trends in changes regarding the frequency and the timing of the heavy daily rainfall events at the four stations. In Paksane in particular, heavy daily rainfall events tended to occur in the latter half of the rainy season.     

Sugar and dry matter changes in potatoes overwintered in soil in Greece

Summary Potatoes were left in the soil from December, when the vines died, until February (cvs Claustar and Sebago) or April (cv. Spunta) in a location of central Greece with light, well drained soils and a mild climate. Tubers were analysed every two months for dry matter and sugar content and usually the dry matter content did not change significantly from December to February or April. The reducing sugars increased from December to February in tubers of all cultivars and significantly decreased in cv. Spunta from February to April.     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

中国马铃薯单倍体诱导进展

马铃薯产量、品质、加工等方面都较其他作物有更大的提升空间,但由于四倍体马铃薯存在遗传基础狭窄且复杂、难以创新等诸多问题阻碍了相关研究的深入开展。利用马铃薯单倍体或双单倍体植株有望解决上述诸多难题。马铃薯单倍体具有加速育种过程、提高选择效率等优点。马铃薯单倍体的获得包括花药培养、花粉培养、孤雌生殖、子房培养。其中,花药培养因更易取材,并且得到胚性细胞团、愈伤组织或胚状体的几率更大等优点而研究最为广泛。获得单倍体植株的成功率与试验材料的基因型、培养条件、培养基添加物等诸多因素相关。根据不同的诱导方法简要阐述了中国马铃薯单倍体研究的历史及进展。