人参基因组RAPD条件的优化

目的确定药用人参最佳随机扩增多态DNA(RAPD)分析方法。方法以药用人参新鲜叶为材料,研究对影响RAPD反应的各因素进行优化。结果药用人参RAPD反应体系及程序为:在25μL反应体系中,含40ng模板DNA,0.3μmol/L随机引物,0.2mmol/LdNTPs,2.5μL10×PCRBuffer,2.0UTaq酶;扩增程序为:第一步94℃预变性2min,第二步94℃变性1min,第三步36℃退火45s,第四步72℃延伸90s,返回至第二步重复40个循环,第六步72℃延伸10min,最后4℃保存以备电泳。结论建立了人参RAPD的优化反应体系及程序。     

十里香茶基因组DNA高效提取与RAPD方法建立

本文以嫩芽和鲜叶为材料,建立了十里香茶高效、微量基因组DNA提取方法,提取的DNAOD260/280在1.7～2.0之间,DNA产率在81.8～483.5 ng/mg之间,能够满足RPAD的需要。同时建立了十里香茶RAPD分子标记方法,25μL PCR反应体系中包含:50 ng DNA模板,1.2μL引物,2.5μL 10×PCR Buffer,2.5μL 25 mMMgCl2,2μL 10 mM dNTP,14.8μL ddH2 O1,U Taq聚合酶。PCR扩增程序为94℃预变性3 min,94℃变性1 min,36℃退火1 min 20 s,72℃延伸2 min4,0个循环后72℃延伸10 min。15个RAPD随机引物以十里香1号DNA为模板,分别扩增出1～7条带。     

甜菜ISSR-PCR反应体系的优化

以甜菜基因组DNA为模板,研究了ISSR的主要影响因素,建立一套适宜于甜菜的ISSR优化反应体系及程序,并对该优化体系进行了验证.实验结果表明:①优化的ISSR扩增的反应体系为:20μL的反应体积中包括2.5mmol/L MgCl2,0.25mmol/L dNTPs,1.5U Taq DNA聚合酶,0.5μmol/L引物,10×PCR Buffer 2μL,100ng DNA模板.②优化的PCR扩增条件为:94℃预变性3min,然后94℃变性30s,45℃退火30s,72℃延伸1min,35个循环后,72℃延伸5min.③利用优化的反应体系仅用1条引物就能将10份甜菜材料区分开.     

台湾麻豆文旦RAPD反应条件的优化

在参考一般RAPD反应程序的基础上,经过反复试验,确定适合台湾麻豆文旦基因组DNA的RAPD扩增程序为(总体积10 ul):模板DNA5 ng,随机引物33 ng,dNTP 1.5 ul,10×PCR buffer 1 ul,MgCl22.0 mmol/L, Taq酶1U.95℃预热2 min,94℃变性30 s,38.7℃退火45 s,72℃延伸45 s,30个cycle后72℃延伸8 min     

假臭草DNA提取及RAPD反应体系的优化

以假臭草叶片为材料，对影响其随机扩增多态DNA(RAPD)反应的各因素进行优化，建立了假臭草RAPD的优化反应体系和程序，即在10 μL反应体系中，5 ng(/10 μL)模板DNA，1.0 μmol/L随机引物F15，150 μmol/L dNTPs，2.0 mmol/L Mg2+，1.0 U Taq DNA聚合酶；扩增程序为95℃预变性4 min，95℃变性40 s，36℃退火40 s，72℃延伸1 min，10个循环，后94℃变性30 s，35℃退火30 s，72℃延伸1 min，35个循环，72℃     

茶树RAPD反应系统和扩增程序优化

以龙井43为材料，使用国产PCR仪，对茶树RAPD分析中影响PCR扩增结果的因素进行了研究，确定了茶树RAPD的最适反应系统和扩增程序，即在25μl反应体系中，含25～50ng模板DNA、2mmol／LMgCl2、各0．2mmo／LdNTPs、0．2μmol／L引物和0．5～1．0UTanDNA聚合酶；扩增程序为：94℃预变性180s，94℃变性60s，38℃退火90s，72℃延伸120s，共进行40～45个循环，最后72℃延伸300～600s，这样可以取得较好的扩增结果。     

苎麻属植物RAPD反应体系影响因子的研究

以苎麻属植物中的4个种为材料，用SDS和CTAB2种方法提取基因组DNA并比较其RAPD分析的效果；对RAPD反应体系中的一些重要参数进行了优化，建立了适合苎麻属植物RAPD分析的反应体系。即在25μL的反应总体积中Mg^2 浓度为1.5mmol/L，dNTPs浓度为0.20mmol/L，40ng模板DNA，Taq酶1.0单位；反应程序为95℃预变性5min；前5个循环为94℃变性1min，36℃结合1min，72℃延伸2min；后40个循环为94℃30s，℃36℃1min，72℃2min（最后1个循环为10min）；共45个循环。该反应体系具有良好的稳定性和重复性。     

大豆SSR检测体系的优化研究

以大豆为试材,研究了大豆SSR检测体系中PCR扩增的各主要成分对检测结果的影响,确立了适宜的退火温度和反应体积,改进了PCR扩增程序和银染方法,进一步优化了适用于大豆的SSR检测体系.优化后的SSR反应体系为:10×Buffer 1.00μL、2.00 ng/μL模板DNA、0.15μmol/L SSR引物、150.00μmol/L dNTPs、0.50 U Taq酶、2.00mmol/L Mg2 ,加ddH20至终体积10.00μL.优化的PCR扩增程序为:94℃预变性3 min;94℃变性25s,47℃退火25s,72℃延伸30s,共35个循环;72℃延伸5min,4℃保存.优化后的检测体系更为经济有效.     

甘薯TD-SSR-PCR反应体系的优化

为探索甘薯最佳TD-SSR-PCR体系,利用L16(43)正交设计研究2×PCR Mix、引物、模板DNA等主要影响因素的适宜浓度,并在此基础上对扩增程序和聚丙烯酰胺凝胶电泳上样量进行优化。结果表明,优化后的TD-SSR-PCR反应体系包括:10μL 2×PCR Mix、100 ng模板DNA、0.4μmol/L引物,1μL甘油,总体积20μL;优化后的扩增程序为:94℃预变性4 min,94℃变性45 s、Tm+5℃~Tm-5℃(每循环退火温度下降0.5℃,Tm选用一对引物中的较小Tm值)退火30 s(退火时间因扩增片段大小而异)、72℃延伸1 min共20个循环,94℃变性45 s、Tm-5℃退火30 s、72℃延伸1 min共15个循环,最后72℃延伸7 min,4℃保存;聚丙烯酰胺电泳上样量以1.5~2μL为宜。在此条件下,利用引物Z37对10份甘薯材料进行PCR扩增,得到的条带清晰、多态性高,表明此条件适用于甘薯的TD-SSR-PCR反应体系。     

巨竹ISSR反应体系的建立与优化

以巨竹叶片提取的基因组DNA为材料,用引物UBC810（序列为GAGAGAGAGAGAGAGAT）研究了PCR反应体系的主要成分、退火温度及循环次数对该种植物ISSR扩增结果的影响。结果表明,20μL的反应体系含40ng模板DNA、0．6μmol·L^-1引物,1．0UTaqDNA聚合酶,2．5mmol·L^-1 Mg^2＋,0．25mmol·L^-1dNTPs,1×Buffer。PCR扩增程序为：94℃预变性5min;94℃变性45s,54．5℃复性30S,70℃延伸90S,循环40次;72℃延伸10min,置4c℃保存。     

Mineral composition of some traditional Mexican teas

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.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

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.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

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.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

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.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

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.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

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.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

<Emphasis Type="Italic">Pulque</Emphasis>, An Alcoholic Drink from Rural Mexico,Contains Phytase. Its <Emphasis Type="Italic">in vitro</Emphasis> Effects on Corn Tortilla

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.