芒果SSR-PCR反应体系的优化

通过正交实验,以芒果品种金煌芒为材料,对影响芒果SSR-PCR反应体系中的Mg2+、dNTPs、Taq酶、模板DNA、引物这5个因素进行了优化。结果表明,各因素水平变化对PCR反应影响的显著性依次为:模板DNAdNTPs引物Mg2+Taq酶。最终确立SSR反应体系的最优条件为:20μL体系中,10×buffer2μL,模板DNA80ng,dNTPs0.4mmol/L,引物0.2μmol/L,Mg2+1.8mmol/L,Taq酶0.75U。     

正交优化芒果SRAP扩增体系及引物筛选

利用正交实验设计,对芒果SRAP-PCR反应的5因素(Mg2+、dNTPs、模板DNA、引物和Taq DNA聚合酶)4水平的扩增效果进行研究,确立适合芒果SRAP-PCR反应的最佳体系。总体积25μL的SRAP-PCR优化的最佳反应体系中含有:2.5μL 10×buffer、20 ng模板DNA、2.5 mmol/L Mg2+、0.2 mmol/L dNTPs、0.4μmo1/L Primer、Taq DNA聚合酶1.5 U。并运用该体系从153对引物组合中初步筛选出50对SRAP引物组合。建立的SRAP标记可为芒果遗传多样性、分子标记及辅助育种等提供研究基础。     

菰SRAP-PCR反应体系的优化与建立

利用单因素分析法对影响菰SRAP-PCR扩增效果的Mg2+、dNTPs、Taq DNA聚合酶、DNA模板和引物浓度5种因素进行了优化。结果表明:建立了适合菰基因组的SRAP-PCR的体系:1μL 10×Buffer、0.5 U Taq DNA聚合酶、2 mmol/L MgCl2、50 ng模板DNA、0.20 mmol/L dNTPs、正反向引物的浓度各为0.7μmol/L,共10μL。选取5对引物,利用该体系对72份菰样本进行PCR扩增,共获得132条清晰的谱带,其中91条具有多态性,比率为68.9%。菰SRAP-PCR反应体系的优化和建立将为利用该标记进行种质遗传多样性分析和连锁图谱构建等研究提供技术支持。     

国兰杂交品种(系)SRAP-PCR反应体系优化及引物快速筛选

以国兰杂交品种(系)为材料,采用L16(45)正交试验设计对Taq DNA聚合酶、Mg2+、dNTPs、模板及引物等5个重要影响因素进行优化,确定国兰杂交品种(系)SRAP-PCR反应的最优反应体系为(25μL体系):Taq DNA聚合酶,1 U;Mg2+,1.8 mmol/L;dNTPs,0.08 mmol/L;模板DNA,100 ng;引物,上下游各0.3 mmol/L;10×PCR Buffer,2.5μL。此外,本试验采用DNA混合池技术(DNA pooling)快速筛选SRAP引物,从180对SRAP引物组合中筛选出39对扩增产物丰富、多态性高的引物组合。与常规方法相比,该技术明显缩短试验周期、节约了模板用量,为快速高效筛选SRAP引物提供了新思路。     

芒果ISSR反应体系的建立与优化

运用L16(45)正交设计对芒果ISSR反应的5个因素,即DNA模板浓度、Mg2+浓度、dNTPs浓度、引物浓度、Taq DNA聚合酶浓度在4个水平上进行优化试验,通过不同反应体系扩增效果比较,建立优化的芒果ISSR反应体系,即25μL的PCR体系中含有DNA模板25 ng、Mg2+浓度为1.5 mmol/L、dNTPs 0.3 mmol/L、引物0.32μmol/L、Taq DNA聚合酶1.25 U。这为进一步运用ISSR标记在DNA分子水平上对芒果种质资源进行分析奠定基础。     

蛋黄果ISSR-PCR反应最佳体系的构建（简报）

利用正交设计的方法,对蛋黄果ISSR-PCR反应的5因素4水平进行试验,试验结果运用SAS9.0软件进行分析.结果表明,在20μL的反应体系中,蛋黄果ISSR-PCR反应的最佳体系为:Taq酶0.75 U,dNTPs 0.2mmol/L,模板80 ng,引物0.25 μmol/L,Mg2+ 1.5 mmol/L.     

石斛属部分植物SRAP-PCR反应体系的建立与优化

建立石斛属(Dendrobium)植物SRAP-PCR反应体系,为石斛的品种鉴定与分类提供理论和技术基础.采用单因素及正交试验对反应体系中的各因子进行优化,确定最优退火温度,并筛选有效引物.结果表明:适用于石斛属植物SRAP 最佳的反应体系为:Mg2+2.5 mmol/L,dNTPs 0.25 mmol/L,Taq D...     

新型植物油莎豆DNA提取与SRAP体系优化

以14个不同地理来源的油莎豆品系为实验材料,研究了油莎豆DNA快速提取方法;以SRAP反应体系中DNA模板量、Mg2+浓度和引物浓度3个因子分别设置3个水平,共配制27个反应体系,对油莎豆SRAP反应体系进行优化。研究结果表明:改良CTAB法可获得较高质量的DNA,参试材料的A260/A280介于1.70～1.98;在27个SRAP反应体系(15μL)中,最优反应体系为DNA模板25ng、Mg2+1.5mmol/L、引物浓度1μmol/L、dNTPs 0.3mmol/L和Taq酶1U,可扩增出清晰稳定的多态性条带。     

狗牙根ISSR-PCR反应体系的优化

利用正交设计试验,对影响ISSR-PCR的Mg~(2+)、dNTPs、引物、Taq DNA聚合酶和模板DNA 5个因素进行优化试验.结果表明:25μL ISSR-PCR反应体系中各因素的最佳条件为Mg~(2+)2.5 mmol/L、dNTPs 0.25 mmol/L、引物0.2μmol/L、Taq DNA聚合酶1.0 U,模板DNA 40 ng.通过对狗牙根ISSR-PCR最佳反应体系进行梯度退火试验,得到引物UBC881的最佳退火温度为50.5℃.该体系在24个狗牙根种质中获得较好的扩增结果,该优化体系为今后利用ISSR技术进行狗牙根属种质资源的遗传多样性分析奠定了技术基础.     

大豆ISSR-PCR反应体系的优化

以黑龙江省大豆为材料,利用正交试验设计,对大豆ISSR-PCR反应体系中的5种主要因素(Mg2+、引物、dNTPs、模板DNA量、Taq酶量)在4个水平上进行体系优化.结果确定了大豆ISSR-PCR反应的最佳体系(25 μL)为:Mg2+浓度1.85 mmol·L-1、dNTPs浓度1.2 mmol·L-1、引物浓度1.2 μmol·L-1、模板DNA60 ng、Taq酶量0.7 U.利用该最佳体系,选取引物855对25份材料进行扩增,以验证该体系的稳定性.建立了适于大豆的ISSR-PCR反应体系,为利用ISSR标记技术开展黑龙江省大豆遗传多样性分析提供了依据.     

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.