李亲缘关系SRAP分析

利用相关序列扩增多态性(SRAP)标记对巴山脆李及达州地区优良脆李资源进行亲缘关系分析,为巴山脆李品种的鉴定和其他李资源的保护及利用提供理论依据。从180对引物组合中筛选出12对多态性高、扩增谱带清晰的SRAP引物,对22份李资源进行扩增,共获得103条谱带,其中多态性谱带64条,多态性比率为60.34%。平均每对引物组合扩增出多态性谱带5.42条。利用UPGMA法构建树状聚类图,在相似性系数0.68处可将22份样品分成3组。聚类结果与按果形分类结果一致,与其地理位置和熟期也存在一定的相关性。     

柱花草种质遗传多样性的SSR和SRAP分析

应用SSR和SRAP标记,对20份柱花草种质的遗传多样性进行研究。从113对SSR引物中筛选出41对多态性较好的引物,共扩增出229个位点,多态性比率达76.86%,平均每个引物扩增多态性位点4.29个。从224对SRAP引物中筛选出25对多态性较好的引物,共扩增出359个位点,平均每个引物扩增多态性10.72个,多态性比率达74.65%。综合SSR和SRAP两种标记对20份材料计算出的遗传相似系数(GS)为0.65~0.90,表明柱花草种质遗传多样性比较丰富;通过UPGMA聚类分析,把这20份材料聚为3个类群,其中类群Ⅰ又分为4个亚类。     

SRAP和SSR标记构建的甘蓝型油菜品种指纹图谱比较

利用SRAP ( sequence - related amp lified polymorphism)和SSR标记构建了甘蓝型油菜品种指纹图谱,并对 两种标记方法进行了比较。结果表明: (1)每对SRAP引物扩增出20. 36个条带,其中4. 44个是清晰、易于辩认的 多态性带;每对SSR引物扩增出3. 88个条带,均为多态性条带。(2)采用25对SRAP和SSR引物分别构建40个和 75个品种的特异指纹图谱, SRAP指纹中具有特异图谱的比例(82. 5%和50. 7% )高于SSR指纹图谱的结果( 60. 0%和44. 4% ) 。品种数越多具有特异指纹的品种越少。(3)运用引物组合法构建品种指纹图谱,大大地提高了指 纹图谱的特异性。25对SSR引物组合扩增97个多态性谱带,两个不同的品种具有相同谱带的概率只有6. 3108 × 10 - 30。组合指纹图谱比组合数码图谱更直观。与SRAP标记相比, SSR标记以其扩增谱带少、易于识别和统计而 更适合用于引物组合法构建品种指纹图谱。     

花生序列相关扩增多态性(SRAP)标记的研究

研究了分属3个市场型的10个中国花生栽培种的序列相关扩增多态性（SRAP）。结果表明，SARP技术可以揭示花生栽培种的遗传差异。在所试验的51对SRAP引物中，2对只获得了单态性条带，其余49对总共产生了1087条带，其中503条（46．27％）为多态性带，每对引物组合平均获得22．18条总带、10．26条多态性带。在这49对引物组合中，总带数和多态性条带的数目分别为7～63和2～32条。 10个花生栽培种间的简单匹配相似系数为0．7712～0．9250不等，根据SRAP指纹图谱进行聚类分析可将这10个品种分为4类。另外一项采用作图亲本24-3和B4的研究中，40对SRAP引物共计获得了160条多态性带。本研究为花生品种鉴定和遗传研究提供了新的DNA分子标记技术手段。     

利用SRAP分析东北地区甜菜品系遗传多样性

采用SRAP分子标记方法对东北地区的100份甜菜材料进行了遗传多样性分析。利用4个表型差异显著的甜菜品系对SRAP的88对引物组合进行扩增,筛选出有效引物组合33对。SRAP的33对引物组合共产生694条扩增带,其中有424条多态性条带,多态性条带的比率平均为61.0%。按照UPGMA方法进行聚类分析,在遗传距离0.20处,将参试材料分为四大类群,分别为高产低糖低抗型、中产高糖高抗型、高产高糖高抗型、高产低糖抗丛根病型。聚类结果与生物学和经济学性状分类基本吻合,较好地显示了甜菜材料丰富的遗传多样性和遗传基础的差异性。遗传相似系数平均值大小为国外引进品种0.8642单胚品系0.7910多胚四倍体品系0.7497多胚二倍体品系0.7101。从聚类图来看,只有个别材料和外国品种聚类到一起,可能是由外国品种杂交改良而成,遗传基础相近。从SRAP扩增条带来看,外国材料只有8～12条,东北材料有16～28条之多,中外材料之间确实存在较大差异,东北材料中缺少丰产基因型,可能是基因组成比较复杂所致。     

燕麦光周期不敏感基因的分子标记

为了寻找燕麦光周期不敏感基因的分子标记,本研究采用SSR及AFLP标记对来自加拿大和中国的22份燕麦材料进行了DNA指纹分析及光周期不敏感基因的分子标记研究。结果表明,所选6对燕麦SSR引物中有3对扩增出多态性高的条带,通过带型分析可以将所研究的多数燕麦品种区分开,所选的10对大麦SSR引物和4对小麦SSR引物在22个燕麦品种中多态性不高,不能将不同燕麦品种区分开来。同时利用AFLP标记对其中5个不同熟期的燕麦材料进行了分析,64对AFLP引物组合经选扩共获得18 240个条带,平均57条/引物组合。统计分析AFLP图谱,获得品种特异条带20条,可将各燕麦品种区分开。此外获得光周期不敏感燕麦品种特异条带2条,可作为燕麦光周期不敏感基因的相关分子标记。     

RAPD和SSR标记检测海南普通野生稻籼粳分化的比较研究

应用RAPD和SSR分子标记技术分别对来自海南省的51份普通野生稻样品籼梗分化情况进行研究.结果表明,40条RAPD引物中筛选出具有多态性的引物15条,共扩增出具有多态性标记位点96个,占总位点的78.05%,所用引物多态性信息量(PIC)平均值为0.720.28对SSR引物中筛选出条带清晰且多态性高的22对引物,共扩增出188个标记位点,其中172个具有多态性,占总位点的92.10%,SSR引物的PIC平均值为0.794.显然,SSR检测出多态性条带的能力优于RAPD.RAPD和SSR标记的分子聚类获得了趋势相近但不完全相同的聚类树状图.聚类结果表明.2种标记均揭示了海南普通野生稻具有一定程度的籼粳分化.其中偏粳多于偏籼.本研究为进一步明确海南普通野生稻在中国栽培稻起源演化上的地位.并对海南普通野生稻资源的发掘利用提供理论依据.     

基于转录组的剑麻SSR标记开发与筛选

本研究基于剑麻转录组测序获得的70110条Unigene序列,采用MISA 1.0软件查找SSR位点,利用Primer 3.0设计SSR引物,通过聚丙烯酰胺凝胶电泳技术对其中的100对SSR引物有效性进行验证.总计获得了13175个SSR位点,SSR的分布频率为15.61％.70110条Unigene序列总计包括60种...     

利用SRAP分子标记技术分析茄子遗传多样性

利用SRAP技术对36份茄子栽培种进行遗传多样性分析。结果表明：22对引物对36份茄子DNA进行PCR扩增，经过染色后共获得292条多态性条带，平均每个引物组合扩增出13.27条多态性条带。36份茄子品种间遗传相似系数在0.568～0.870，平均遗传相似系数为0.757，这表明该群体的遗传背景相对狭窄。利用UPGMA法对36份茄子资源进行聚类分析，结果显示，在相似系数为0.690处，可将36份茄子资源划分为5个组。     

新型特早熟春性甘蓝型油菜的遗传多样性及其杂种优势

利用SSR和SRAP两种分子标记技术研究了通过甘蓝型油菜与白菜型油菜种间杂交培育出的新型特早熟春性甘蓝型油菜品系的遗传多样性,利用其中10个恢复系和3个保持系转育而来的不育系进行NCⅡ双列杂交,测定其杂种优势,并分析遗传距离与杂种优势的关系.研究结果表明:(1) 30对SRAP引物扩增出250条多态性条带,多态性比率为61.9%.39对SSR标记共扩增出145条多态性条带,多态性比率为97.3%.(2)两种标记混合聚类结果表明,在相似系数0.588处可将全部材料划分为A、B两大类群,其中A类包含一个来自039×浩油11号的甘白种间杂交后代和白菜型亲本浩油11号,B类包含039、E144和其余的甘白种间杂交后代.在相似系数0.714处B类又可以分为6个不同的亚类,两个甘蓝型亲本材料单独聚在一个亚类中,其余的64份甘白种间杂交后代分别聚在5个不同的亚类中,说明新型特早熟春性甘蓝型油菜品系具有丰富的遗传多样性.(3)配制的30个杂交组合中,产量超亲优势在20%以上的有22个,占组合数的73.3%,产量杂种优势非常明显,而含油量杂种优势不明显.(4)SRAP标记遗传距离与产量杂种优势达到极显著正相关;而SSR标记遗传距离与产量杂种优势相关不显著.因此,利用分子标记技术预测油菜的杂种优势,SRAP标记效果更好.     

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.     

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.     

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.