利用正交设计优化甘蔗SRAP-PCR反应体系

利用正交设计L16(45)对甘蔗SRAP-PCR反应体系的五大因素(Mg2+、dNTPs、引物、模板DNA、Taq酶)在4个水平上进行优化,得到如下结论:各因素水平变化对PCR反应的影响从大到小依次是:Mg2+、dNTPs、引物、Taq酶和模板DNA;通过对各因素进行筛选,建立甘蔗SRAP-PCR反应的最佳体系(20μL)为:dNTPs 0.25 mmol/L、引物0.1μmol/L、Mg2+2.5 mmol/L、Taq酶0.25U和模板DNA 60 ng。     

柱花草DNA提取及ISSR反应体系的正交优化

报道了以新鲜嫩叶提取高纯度、完整性好的柱花草基因组DNA方法.并利用正交设计,从Taq聚合酶、Mg2 、dNTP、DNA模板、引物浓度5个因素、4个水平对柱花草ISSR反应体系进行优化试验,确立了适合柱花草的快速而又高效的ISSR反应体系,即20 μL反应体系中含1×PCR缓冲液,2.0 mmol/L Mg2 ,0.2 mmol/LdNTP,0.4 μmol/L引物,60 ng DNA模板,1 U Taq聚合酶.     

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。     

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.     

橡胶树MSAP技术体系的优化与建立

通过对酶切反应最少酶用量及选择性扩增体系的优化,建立了橡胶树MSAP最佳反应体系。研究结果表明,500 ng橡胶树叶片基因组DNA,用EcoRⅠ、HpaⅡ和MspⅠ各0.5 U,在37℃酶切4 h,即可完全酶切。优化的选择性扩增体系为:Mg2+1.5 mmol/L、dNTPs 250μmol/L、引物0.15μmol/L、Taq DNA聚合酶1 U;使用该体系,可获得清晰稳定的橡胶树MSAP图谱。     

咖啡ISSR与RAPD-PCR反应体系优化

以中粒种咖啡部分种质为试材,采用U25（55）均匀设计表,对影响ISSR和RAPD标记的模板DNA、Mg2+、dNTPs、TaqDNA聚合酶和引物浓度5个因素进行优化,分别建立适合于中粒种咖啡ISSR-PCR和RAPD-PCR标记的反应体系。结果表明：2种标记的反应体系相似,20 μL的反应体系中含DNA模板20 ng,Mg2+ 1.5 mmol/L,dNTPs 0.3 mmol/L,Taq酶1.25 U,引物0.6 μmol/L。利用所确立的体系对13份中粒种咖啡种质进行扩增,结果条带清晰明亮,多态性好     

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。     

基于B/S结构的农产品质量安全追溯系统研究

以蝴蝶兰嫩叶提取的DNA为材料,蝴蝶兰SRAP反应体系中的重要参数Mg2+、Taq酶、模板DNA及随机引物,建立了一套适合蝴蝶兰基因扩增的SRAP反应体系：25 μL的反应体系中Mg2+浓度为2.0 mmol/L,Taq酶1.0 U,DNA模板40 ng,上下游引物0.8 mmol/L。该体系扩增条带清晰,重复性好,有望在蝴蝶兰属植物的遗传育种研究中运用。     

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.     

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.     

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.     

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.     

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.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.