瓜实蝇DNA甲基化的MSAP体系建立与优化

瓜实蝇[Bactrocera cucurbitae (Coquillett)]是中国重要的蔬菜害虫,但其DNA甲基化研究尚未见报道。甲基化敏感扩增多态性是研究DNA甲基化的重要技术之一。通过对酶切反应、连接、PCR扩增和引物筛选等条件优化,建立瓜实蝇MSAP反应体系,即：①20 μL酶切体系中加入10 U的限制性内切酶与600 ng基因组DNA,于37℃酶切反应过夜;②20 μL连接体系中加入T4 连接酶1 U,HpaⅡ-MspⅠ-adapter接头50 pmol,EcoR I-adapter接头5 pmol,并于16℃反应12 h;③连接产物稀释后进行PCR预扩增和选择性扩增,再经6%变性聚丙烯酰胺凝胶电泳和银染检测结果。通过该体系筛选出适用于瓜实蝇基因组DNA甲基化多态性研究的6对引物;瓜实蝇MSAP体系为瓜实蝇的表观遗传学研究提供了技术支持。     

建立番木瓜性别研究的cDNA-AFLP分析体系

以番木瓜幼苗为材料,利用多重PCB技术快速鉴定其性别.建立适合番木瓜性别研究的cDNA-AFLP分析体系,分析影响cDNA-AFLP分析体系的各种可能因素(RNA提取、酶切与连接效率、预扩增效果等),并对影响选择性扩增反应的各因子进行优化.结果表明,选择性扩增的最佳体系,即在反应体系中,各因素终浓度分别为:Ta[酶0.06U/μL;L;Mg2+2.4mmol/L;dNTP 2.0mmol/L;引物0.48 μmol/L.通过优化体系得到的选择性扩增产物,银染检测后条带清晰稳定.表明成功建立了适合番木瓜性别研究的cDNA-AnLP分析体系.     

柱花草AFLP反应体系的建立与引物筛选

以柱花草奥克雷品种为材料，采用改良的CTAB法提取基因组DNA，对影响AFLP反应体系的主要因素进行了优化，建立了柱花草的AFLP反应体系。结果表明：20 μL为最佳反应体系，酶切体系中DNA模板量为1 000 ng，用5 U EcoR I 37℃酶切2 h、5 U Mse I 65℃酶切2 h效果最佳；分别取5 μL酶切液、1 μL T4连接酶(5 μL/L)、1 μL EcoR I接头、1 μL Mse I接头、2 μL缓冲液(T4DNA酶自带)，于22℃下连接10 min效果最佳；预扩增体系中模板稀释15倍、Mg2+浓度为0.75 mmol/L、Taq酶用量为1 U、dNTPs浓度为0.2 mmol/L、引物浓度为2 ng/μL效果最佳；选择扩增体系中模板稀释20倍、Mg2+浓度为1.25 mmol/L、Taq酶为1 U、dNTPs浓度为0.225 mmol/L、引物浓度为0.4 ng/μL效果最佳。利用热研5号、奥克雷2个品种对8对引物组合进行筛选，筛选出46对引物组合，为利用AFLP标记对柱花草进行分子生物学研究及分子育种奠定基础。     

荔枝果皮cDNA-AFLP分析体系的建立

以荔枝果皮为材料,对cDNA-AFLP的选择性扩增体系进行优化,建立了适宜荔枝果皮的cDNA-AFLP分析体系,并得到了较为清晰可辨的cDNA-AFLP指纹图谱。结果表明,20μL选择性扩增的最佳体系中,各因素终浓度分别为:模板cDNA 30 ng、dNTP 0.25 mmol/L,引物0.6μmol/L,Extaq酶0.75 U。     

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.     

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。     

沉香属植物基因组DNA提取及SSR反应体系的优化

以白木香为材料,研究沉香属植物基因组DNA提取方法,并优化SSR-PCR反应体系。通过改良CTAB法提取白木香叶片基因组DNA,经电泳和吸光度检测。优化影响白木香SSR-PCR主要参数,确立适合沉香属植物的SSR-PCR反应体系和扩增条件：在20 μL反应体系中,模板DNA、引物、Mg2+、dNTP和Taq DNA聚合酶等5种主要成分的最适浓度分别为2.5 ng/μL、1 μmol/L、2 mmol/L、0.2 mmol/L、1.2 U;并用9份沉香属植物DNA样品对SSR-PCR反应体系验证,能扩增清晰     

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。     

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。     

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.     

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.     

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.     

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.     

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.     

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.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).