利用RAPD、ISSR分子标记分析野牡丹属亲缘关系

采用ISSR和RAPD分子标记技术对9个种44份野牡丹属种质资源进行了亲缘关系分析。结果表明:11条ISSR引物共扩增出91条谱带,其中多态性条带90条,多态性条带的比率为98.9%;16条RAPD引物共扩增出113条谱带,其中101条多态性条带,多态性比率为89.38%。2种分子标记相比较,ISSR分子标记检测出的多态性比率更高。44份野牡丹属种质明显聚为2组,种质资源遗传相似系数在0.61~0.88,平均相似系数0.75。基于不同引物的条带组合构建了供试的44份野牡丹属种质资源的ISSR和RAPD指纹图谱,采用这2种指纹图谱可对供试的所有野牡丹属种质资源进行鉴定。     

尖孢镰刀菌致病性菌株遗传多样性的ISSR分析

致病性尖孢镰刀菌（Fusarium oxysporum）是一种世界性分布的作物土传病原真菌,为明确其不同寄主及专化型菌株遗传差异性和亲缘关系,利用ISSR分子标记技术对来源于不同寄主（专化型）及地理分布的43个菌株进行了遗传多样性分析。结果表明,供试的15条引物通过ISSR-PCR 扩增,共扩增出147条条带,其中多态性条带为144条,平均多态性条带达98.0％。43个菌株的聚类结果表明,各菌株间的遗传相似系数为0.67～0.97,且遗传多样性与其寄主和地理来源没有明显的相关性。进一步将供试菌株中葫芦科与茄科作物尖孢镰刀菌分别进行聚类分析,当遗传相似系数为0.84时,16个葫芦科的菌株可分为6个ISSR类群;当遗传相似系数为0.77时,16个茄科的菌株亦可分为6个ISSR类群;且均表现为相同寄主或专化型菌株因地理来源不同,被归属于不同的ISSR类群,说明寄主或专化型相同的菌株与地理来源存在一定的相关性。     

橡胶树抗寒种质遗传多样性分析

应用RAPD和ISSR技术对20份橡胶树抗寒种质进行遗传多样性分析。结果表明，16个RAPD引物和12个ISSR引物分别扩增出条带113和101条，多态性条带指数(PPB)分别为61.1%和63.4%。据Nei-Li相似系数，ISSR标记在相似系数约0.74处，可将20份材料分为野生种质和栽培种质两大类；RAPD标记在相似系数约0.70处，也可将供试材料分为野生种质和栽培种质两类，但只有XJ002420为野生种质。对2种标记的分析结果进行相关分析，结果表明，RAPD和ISSR所检测的遗传相似系数呈极显著正相关，相关系数为0.672。以上结论表明，RAPD和ISSR标记可用于橡胶树种质资源的遗传多样性研究，但鉴于ISSR较RAPD有更强的多态性检出能力，ISSR技术应作为遗传多样性研究的首选单引物标记。     

黄灯笼辣椒种质资源遗传多样性ISSR分析

采用ISSR分子标记技术对22份国内外黄灯笼辣椒种质的遗传多样性进行了分析,为选配黄灯笼辣椒杂交育种亲本选择提供了参考.根据加拿大哥伦比亚大学公布的100对ISSR引物,从中筛选出17条多态性好、条带稳定的引物,用其对22份黄灯笼辣椒种质进行扩增,共获得154条谱带,其中140条为多态性条带,多态性比率为90.9％,表明ISSR标记对黄灯笼辣椒具有较高的多态性;通过对黄灯笼辣椒ISSR遗传相似系数的统计与分析,品种间的遗传相似系数在0.461～0.870之间,平均为0.778.聚类分析表明,22份材料在遗传相似系数0.52处分为2类,其中L508为种间杂种后代,与其它种质具有较远的亲缘关系,单独为一类;在遗传相似系数0.72处可以分为4类,把不同亲缘关系的种质明显区分开来,表明ISSR分子标记进行黄灯笼辣椒遗传多样性的分析是可行的.黄灯笼辣椒品种间具有较丰富的遗传多样性,并为黄灯笼辣椒品种的选育和种质资源的保护提供了理论依据.     

尖孢镰刀菌胡麻专化型(Fusarium oxysporum f . sp. lini) ISSR标记聚类分析

结合形态学特征和分子生物学方法对我国尖孢镰刀菌胡麻专化型菌株进行鉴定、聚类分析和遗传变异分析。结合传统分类方法和ITS序列分析,确定6省区96株菌株为尖孢镰刀菌。采用ISSR（简单重复序列区间）分子标记技术对这96株菌株进行分析,12条引物共扩增出800个条带,多态性条带数为797条,多态性为99.62%;在相似性系数为0.88处,96株供试菌株被分为5个类群。聚类结果表明,胡麻枯萎病菌种内存在明显的多态性,且ISSR类群与地理来源存在相关性。     

银耳芽孢遗传多样性分析

利用ISSR和RAPD分子标记分析了不同来源的14株银耳芽孢多样性.4个ISSR引物和2个RAPD引物总扩增条带数为40条带,其中多态性位点数为39,多态性位点百分比97.50%.平均等位基因位点数为1.9750,平均有效等位基因位点数为1.393 1,物种水平上Nei's基因多样度指数为0.2270,Shannon遗传多样性指数为0.3559.UPGMA聚类方法对14个银耳菌株进行聚类分析,聚类结果表明,福建省内栽培的不同银耳菌种芽孢没有差异,福建省内银耳菌种比较单一,遗传背景相当狭隘;但这些菌株的芽孢与野生采集分离的银耳菌株的芽孢存在一定的差异.     

利用醇溶蛋白、盐溶蛋白和RAPD标记划分玉米自交系类群的比较研究

利用醇溶蛋白、盐溶蛋白和RAPD分子标记研究了16个玉米自交系的遗传多样性,并对这16个自交系进行聚类分析。结果显示,在供试材料中筛选到多态性、重复性均比较好的随机引物13个,检测到醇溶蛋白、盐溶蛋白和RAPD标记的多态性条带分别为30条、34条和112条,分别占总带数的83.3%、85.0%和86.8%。3种标记所得遗传相似系数的相关性均达到了极显著水平,所得平均遗传相似系数(0.597、0.541、0.554)基本一致,RAPD标记的遗传相似系数标准差最小(0.080),相对较可靠。依据醇溶蛋白、盐溶蛋白和RAPD分子标记分别将16个供试自交系划分为3类、3类和4类,聚类分析结果都与系谱分析大体相似,同时也存在与所知系谱不符的现象。     

广东地区野生狗牙根遗传多样性的ISSR分析

应用ISSR标记,对广东地区30份野生狗牙根进行遗传多样性研究。从50个ISSR引物中筛选出15个多态性明显、反应稳定的引物,共扩增出151条谱带,平均每个引物能扩增出10.07条带,其中多态性条带总数为142条,多态性条带比率达93.7%。材料间遗传相似系数GS=0.58278～0.92715。基于遗传相似系数,利用UPGMA聚类分析表明,供试材料可聚为4类。POPGENE分析软件结果表明,平均Shannon信息指数I=0.5689,平均Nei's基因多样性h=0.3813,每位点平均有效等位基因数ne=1.6196。     

大豆疫霉菌遗传多样性的RAPD分析

利用随机扩增DNA (RAPD)技术分析了15个大豆疫霉菌( Phytophthora sojae)的遗传多样性,并同其它7 个疫霉种的8个菌株进行了比较。运用筛选出的12个引物共获得152个RAPD标记,其中84. 2%具有多态性。通 过聚类分析结果表明,疫霉属种间的遗传相似系数的变化幅度为0. 533～0. 783,大豆疫霉菌与其它几种疫霉的遗 传距离相对较远,用引物OPB06扩增到P. sojae种特有的一个RAPD标记; P. sojae种内菌株间遗传相似系数的变化 幅度为0. 855～0. 967,亦存在较丰富的遗传多样性,该遗传多样性与菌株毒力之间有一定相关性,而与菌株地理来 源没有相关性。     

东北地区玉米弯孢菌的致病性分化与RAPD分析

在东北三省15个地区采集分离26个玉米弯孢菌菌株,通过鉴别寄主技术与RAPD分子标记技术进行致病性与遗传分化的研究。结果表明,东北地区玉米弯孢菌在致病性与遗传上都存在明显的变异,二者有一定的相关性,未发现变异程度与菌株地理来源有明显的直接关系。26个菌株的致病性分为5种类型,其中中等致病类型分布遍及东北三省,为优势致病类群;强致病类型分布在吉林省的白城市;弱致病类型主要分布在吉林省的白山和梨树。用8个引物对供试菌株进行RAPD扩增,共获得77个RAPD标记,其中多态性标记71个,多态性比例92.2%。供试菌株在相似系数约0.71处共聚为4组,大多数致病性较强的菌株聚在一起,而弱致病株在相似系数相对较低时和其他菌株聚在一起。     

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).