老虎须的组织培养与植株再生

以老虎须茎段为试验材料,采用不同激素组合对其进行愈伤组织诱导和分化、芽增殖与生根研究。结果表明：老虎须茎段愈伤组织诱导和分化的最适培养基分别为MS＋6-BA 1.0 mg/L＋KT 3.0 mg/L＋NAA 0.5 mg/L和MS＋6-BA 1.0 mg/L＋KT 1.0 mg/L＋NAA 0.5 mg/L;芽增殖的最适培养基为MS＋6-BA 2.0 mg/L＋IAA 0.2 mg/L;生根的最适培养基为1/2 MS＋IBA 0.5 mg/L。     

高品质甜叶菊品系“1096”的组培快繁

采用改良DNS等方法筛选出的生长快、糖苷含量高的甜叶菊品系1096为材料,研究了不同外植体、不同激素种类和配比对愈伤组织诱导、不定芽分化和生根的影响。结果表明:以茎尖为外植体愈伤组织和不定芽诱导率均最高;其次是带腋芽茎段;再次为叶片。无腋芽茎段和无菌根均能诱导出愈伤组织,但不能诱导成芽。茎尖不定芽诱导的最佳培养基为MS+6-BA 1.0mg/L;叶片不定芽诱导的最佳培养基为MS+6-BA 1.0mg/L+IAA 1.0mg/L;带腋芽茎段不定芽诱导的最佳培养基为MS+6-BA 1.5mg/L。不定芽继代增殖培养采用MS+6-BA 0.5mg/L+NAA0.05mg/L;在1/4MS+IBA 0.1mg/L+NAA 0.1mg/L+1g/L活性炭的培养基上诱导生根,生根率可达100%,生根苗移栽后成活率达95%。     

猫尾射的组织培养

以猫尾射无菌播种苗(去除根部)为外殖体,对其愈伤组织诱导和分化及其不定芽增殖进行研究。结果表明,外殖体在MS＋6-BA 1.0 mg/L＋NAA 0.1 mg/L培养基上,愈伤组织诱导和分化的效果较好,愈伤诱导率为82.0%,分化率为74.5%;经不定芽增殖培养基MS＋6-BA 0.5 mg/L＋NAA 0.05 mg/L培养,不定芽增殖倍数为8.2,平均株高为4.7cm。组培苗在MS＋IBA 0.5 mg/L培养基上生根率达90%。生根苗移栽成活率达84%。     

外植体和培养因子对剑麻不定芽诱导及植株再生的影响

以剑麻H.11648为材料,研究不同外植体、培养基和激素对不定芽诱导及生根的影响。试验结果表明,以珠芽苗茎尖为最佳快繁材料,最佳消毒时间25 min,最适合的基本培养基为SH;最佳分化培养基为SH＋NAA 0.05 mg/L＋6-BA 4 mg/L,芽的分化率达到85%,同时可做增殖培养基,增殖平均倍数为18。分化芽在MS和SH两种培养基中添加NAA 0.1 mg/L＋6-BA 0.1 mg/L中均可生根,生根率为95%。     

频繁开花高产小桐子组织培养的初步研究

为了奠定频繁开花型高产小桐子的快繁及转基因基础,通过对小桐子茎段腋芽培养、叶片和叶柄愈伤诱导及不定芽分化的不同激素组合培养进行研究。结果表明：适合该高产品种的茎段培养的最佳培养基为MS＋6-BA 0.5 mg/L＋IBA 0.1 mg/L,叶片愈伤诱导及不定芽分化培养基为MS＋6-BA 2.5 mg/L＋IBA 0.5 mg/L,叶柄愈伤诱导及不定芽分化培养基为MS＋6-BA 1.0 mg/L＋IBA 0.2 mg/L,生根培养以1/2MS＋IBA 0.5 mg/L＋AC 0.1%较为适宜。引起小桐子组培苗玻璃化现象的主要原因之一是BA浓度过高;在不定芽的分化培养中,愈伤过多会严重影响不定芽的数量及质量。     

白掌的离体快速繁殖初探

以白掌带顶芽或腋芽茎段，进行组培试验，研究表明：适合诱导培养基为1／2MS＋6-BA3．0mg／L，诱导率为100％；适合不定芽增殖培养基为Ms＋6-BA4mg／L＋NAA0．5mg／L，适合生根诱导培养基为1／2MS＋NAA1．0mg／L或1／2MS＋IBA1.0mg／L，生根率可达90％以上；继代过程中次数多了会出现玻璃化现象，而6-BA浓度4或0．5mg／L的交替使用有效减低玻璃化的发生，也有利于芽苗的增殖。     

辣木离体组织培养技术研究

为建立辣木离体组织培养体系,以辣木嫩枝为外植体,对外植体的选取与消毒、不定芽的诱导及增殖、炼苗移栽等技术进行研究。研究结果表明,用75%酒精消毒1 min,再用0.1%HgCl_2消毒25 min,污染率和褐化率均能保持相对较低水平。以辣木带腋芽茎段为外植体,不定芽的最佳诱导和增殖培养基分别为MS+0.5mg/L6-BA+20g/L蔗糖和MS+0.5mg/L6-BA+0.2mg/LNAA+30g/L蔗糖,芽的诱导率和增殖系数分别可达73.3%和5.6。辣木生根培养基最佳配方为1/2MS+2mg/LNAA+0.2mg/L6-BA+20g/L蔗糖,生根瓶苗经炼苗10天后移栽至泥炭土:珍珠岩=1:1的基质中成活率可达80.6%。     

蜻蜓凤梨叶片组织培养植株再生的研究

以蜻蜓凤梨试管苗叶片为外植体进行离体再生研究。结果表明，叶片诱导直接分化不定芽的最佳培养基是MS＋BA 5.0 mg/L＋IBA 1.5 mg/L，分化率高达80%。增殖培养基为MS＋BA 0.5 mg/L＋NAA 0.2 mg/L。壮苗培养基为MS＋NAA 2.0 mg/L。生根培养基为MS＋NAA 2.0 mg/L＋AC 0.5 g/L，生根率达100%。     

银后粗肋草的离体培养和快速繁殖

以银后粗肋草的幼嫩叶片为材料,研究不同植物生长调节剂组合对愈伤组织诱导和分化的影响;以带侧芽的茎段为材料,研究不同接种方式、不同6-BA和NAA组合对丛生芽诱导的影响;以愈伤组织诱导的不定芽和茎段诱导的丛生芽为材料,研究不同植物生长调节剂组合对丛生芽的增殖和生根的影响;最后研究不同移栽基质组合对试管苗移栽成活的影响。结果表明:(1)叶片接种在MS+6-BA 2.5 mg/L+NAA 0.1 mg/L培养基培养中60 d后,愈伤组织诱导率为63.41%,不定芽再生率为26.88%,平均生成芽数为3.80个。(2)带侧芽的茎段水平放置接种在MS+6-BA 2.0 mg/L+NAA 0.1 mg/L培养基上,丛生芽诱导率为91.91%,平均生成芽数为5.29个。(3)将经叶片诱导愈伤组织分化所得的不定芽和经茎段诱导所得的丛生芽切成单株,接种到MS+6-BA 3.0 mg/L+NAA 0.1 mg/L或MS+KT 3.0~4.0 mg/L+NAA 0.1 mg/L增殖培养基中,不定芽和丛生芽增殖和生长良好。(4)将在增殖培养基中长至4 cm以上的小植株转入到1/2 MS+NAA 0.2 mg/L的生根培养基中培养20 d后,生根率达100%,平均根长4.49 cm,每株平均根数6.80条。(5)生根苗移栽到1/2木屑+1/4珍珠岩+1/4菜园土混合基质中,成活率达95.40%。     

苎麻茎尖的组织培养及其诱导植株的再生

对苎麻50号品系的茎尖进行组织培养并诱导植株再生。结果表明:最适茎尖转绿和分化的培养基是1/2MS 6-BA1.0mg/L CH300mg/L的液体培养基,茎尖分化率为100%。最适成苗培养基为MS 6-BA0.5mg/L IAA0.1mg/L CH300mg/L,成苗率是53.3%。扩繁培养基为MS 6-BA0.3￣1.0mg/L,繁殖系数达6.7。适宜生根培养基为1/2MS NAA0.01mg/L。最佳茎尖剥取材料是无菌试管苗,茎尖长以0.3mm带1￣2个叶原基为宜。从茎尖接种培养成苗到移栽需4个月左右。     

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).