沼液对烟苗生长及生理特征的影响

在有机烟叶生产中,为替代化学肥料,提高有机肥源在烤烟育苗中的利用效率,以烤烟育苗专用肥为对照(CK), 研究沼液营养液氮浓度分别为50、150、250 mg/L 对烟苗生长及生理特性的影响。结果表明,与CK 相比,氮浓度为50 mg/L 的处理烟苗矮小,营养液中的养分难于满足烟苗生长的需要;氮浓度为150 mg/L 的处理烟苗长势较好,能显著增加烟苗根系的干、鲜质量,同时,总根长、根表面积、体积、根系活力均有不同的程度的增加。而叶片中光合色素含量、光合特性、 生理特性各指标与CK 相比差异不大。综合来看,氮浓度为150 mg/L 的处理能够达到使用漂浮育苗专用营养液的效果,可用于有机烟草育苗生产。     

基质中添加育苗肥对烟苗生长及生理特性的影响

为缩短烤烟育苗周期、提高烟苗素质,在育苗基质中添加了不同用量的烟草专用育苗肥进行对比试验。结果表明:基质中添加520 g/m3育苗肥时,烟苗各生长期缩短,育苗周期较对照减少8 d。其中,从出苗到小十字期的生长时间缩短最多,为3.38 d;成苗期烟苗根系数量最多、质量最大,烟苗农艺性状指标最高,根系活力、叶片叶绿素含量(质量分数)和硝酸还原酶活性也最高。因此,在基质中加入适量(520 g/m3)育苗肥可促进烟苗生长,明显缩短烟苗生育期,同时培育出的烟苗根系发达,根系活力强。      

恩施烟区培育壮苗的加热技术研究初报

通过对育苗池底施加不同功率的地热线,拟探索通过苗床加热提高漂湿育苗营养液和盘面温度满足烟苗生长发育,为恩施烟区培育适时烟草壮苗提供科学的育苗方法。研究结果表明,育苗池底铺加地热线均能提高育苗温度和烟苗的生长速度,有效缩短烟苗育苗时间,促进了烟苗生物量的积累,烟苗的整体素质有一定提高。因此,结合恩施烟区地理特征,低山、二高山和高山烟区可分别在育苗池内底部铺加10、20和40 W/M²功率地热线加热,满足烟苗生长所需的温度条件,确保烟苗适时移栽。     

烤烟漂浮育苗营养液增温配套措施研究

为了抵御倒春寒对烟苗生长造成的不利影响,研究了漂浮育苗营养液增温的7种不同方式及其对烟苗生长的影响。结果表明,7种不同增温措施均可在温度较低的夜间将营养液温度控制在25~28 ℃,提高室内温度及基质温度3~4℃;烟苗出苗及漂浮育苗期分别缩短7、20 d以上;出苗率和烟苗素质明显提高。     

烤烟湿润育苗技术研究

对以育苗基质和营养液配方的筛选、肥水管理方式的改进和不同育苗方式比较为主要内容的烤烟湿润育苗技术进行了探讨。结果表明,10号育苗基质配方和2号营养液配方所育烟苗综合素质最高,茎高、茎围适中,根系发达,根系活力强,根茎叶干鲜重最重;育苗肥水管理方式由传统的"一段式"改为"前期浅灌、后期浇施"的"二段式",不仅大大降低了烟农的育苗用工,而且解决了肥水单纯采用浇施,导致基质易板结、出苗率较低、生长不整齐等问题;与漂浮育苗相比,该技术不仅保持了漂浮育苗的优势,同时提高了成苗期烟苗的素质,有效地解决了返苗期偏长的问题。     

过氧化钙增氧对漂浮育苗烤烟生长的影响

为解决漂浮育苗过程中烟苗遭受低氧胁迫,研究了过氧化钙增氧的效果以及对烟苗的根系活力、生物量、植物学性状和烟株大田生长的影响。结果表明:营养液中添加过氧化钙可提高溶解氧含量,提高根系活力、生物量和根冠比,缩短移栽后还苗时间,促进大田烟株生长。其中,过氧化钙浓度为450 g/m3的处理效果最好,与对照比,根系活力、总生物量干重、根冠比显著提高了87.5%、18.8%、14.15%,烟苗移栽后,还苗时间缩短3.4 d,自然株高提高12.1 cm。      

补充光照及微量元素对烟苗生长的影响

为克服我国东南烟区冬春漂浮育苗受低温寡照影响导致烟苗生长发育不良的障碍,培育抗逆性强的高茎壮苗,研究了在育苗工场内用不同波长植物生长灯补充光照和在育苗肥中添加硼、锰微量元素对烟苗生长和主要生理指标的影响。结果表明,与对照和全蓝光相比,采用蓝:红2:1和蓝:红1:1的植物生长灯搭配补光,对烟草漂浮苗株高、茎围的生长及叶片中叶绿素和类胡萝卜素含量有明显的促进作用,方差分析和多重比较结果均达到极显著水平;在漂浮育苗肥中添加100 mg/kg硼元素或200 mg/kg锰元素可显著增加烟草漂浮苗的株高、茎围、叶长及根系活力和蛋白质含量,添加锰元素还有助于增加叶片中叶绿素和类胡萝卜素含量。说明补充光照和微量元素有助于烟草漂浮育苗的生长。     

烟草漂浮育苗系统中培养基质对烟苗生长发育影响的研究

本文研究了烤烟漂浮育苗系统中培养基质对烟苗生长发育的影响。结果表明,1.漂浮育苗基质中有机质材料的比例对烟苗生长发育具有重要作用。在以草炭、蛭石、膨化珍珠岩为原料的培养基中草炭比例以5 0%~70%较为适宜,低于40%或高于80%均影响烟苗根系的发育。2.有机质材料的选择应充分利用当地自然资源条件,因地制宜开发利用。以一定比例的腐熟作物残体代替草炭亦是完全可行的,同样能够培育出根系发达,均匀一致的壮苗。3.基质配比确定后,苗盘中基质容重对烟苗影响较大。试验以美国漂浮育苗商品基质Sunshine Tobacco Mix L 5为材料,证明苗盘装填容重在0.15~0.2 5 g/m L适宜于烟苗的生长发育。4.基质中加入少量的肥料,有利于烟苗前期的发育,肥料浓度超过5 0 mg/L即影响烟苗生长。试验显示营养液中的氮和钙、镁、铜、铁、锰等元素在基质上部富集,可产生肥料盐害。5.漂浮育苗与传统育苗方式相比,烟苗移栽大田后还苗快,生长迅速,增加收获叶片数,促进烟株开片开秸,为烟叶的优质丰产奠定了良好的基础。      

干湿和变温处理对烟草种子萌发的影响

为寻求烟草种子的最佳引发方式,提高丸化种子的发芽率、培育健壮烟苗,采用昼温20℃、夜温10℃的变温和干湿锻炼处理烟草裸种,然后包衣丸化,并对烟草裸种和丸化种芽进行了室内发芽和田间育苗试验.结果表明变温和干湿同时处理可有效地提高烟草种子活力,处理后的烟草丸化种芽较普通包衣种子的发芽率提高17.92%～18.81%,出苗率提高11.56%～15.94%,出苗和成苗时间分别缩短3～4d和7～8d.培育的烟苗根系发达,烟苗整齐度和壮苗率也显著提高.     

烟草漂浮育苗有害藻类致病机制及其防治研究进展

烤烟漂浮育苗技术自21世纪初叶在我国大面积应用以来,已在我国的烟叶生产中发挥了重要的积极作用.然而,漂浮育苗系统的环境特点却极易导致藻类滋生.有害藻类的大量繁殖不仅会与烟苗竞争养分和溶氧,还会导致营养液理化指标下降,不利于烟苗正常生长发育.同时,许多有害藻类产生的藻毒素能够严重抑制烟草种子萌发和幼苗生长,危害烟苗健康,...     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the