紫罗兰愈伤组织诱导及植株再生的研究

以紫罗兰幼苗子叶、子叶柄、下胚轴作外植体接种MS附加不同激素的培养基诱导愈伤组织，并进一步诱导分化出芽及再生植株。子叶和下胚轴外植体在MS＋0.1mg/LNAA培养基上愈伤组织发生率达100％，下胚轴愈伤组织转移MS 0.1mg/L 6-BA培养基上易诱导分化出小苗，分化频率达67％，再生小苗在1／2MSA＋0.2mg/L IBA培养基上生根率达86％。     

二步培养和AgNO3对甘蓝型油菜子叶和下胚轴芽再生的影响

以甘蓝型油菜（Brassica napus L.）品种“浙双758”为材料,研究二步培养及添加AgNO3对甘蓝型油菜子叶和下胚轴外植体离体再生的影响。外植体先在含0.5-1.5 mg/L 2,4-D的MS培养基上 “预培养”3 d 或7 d诱导愈伤组织的产生,再转到含有3 mg/L BA和0.15mg/L NAA及添加或不添加2.5 mg/L AgNO3的分化培养基上诱导芽的分化。结果表明,外植体愈伤组织诱导率和芽再生率与2,4-D浓度、预培养时间和AgNO3密切相关;分化培养基中添加银离子可显著增加不定芽的再生频率;二步培养及添加AgNO3可使半子叶、完整子叶和下胚轴外植体芽再生频率分别达到了96.1%,96.7%和96.7%。     

2个葡萄品系外植体愈伤组织诱导和植株再生

进行了无核白、红地球2个葡萄品系外植体愈伤组织诱导和植株再生的研究。通过葡萄品系无核白、红地球叶片和叶柄外植体的愈伤组织的诱导、再分化,以器官发生途径实现植株再生。结果表明:(1)愈伤组织诱导以MS+BA5mg/L+NAA0.5mg/L+蔗糖40g/L培养基最佳,诱导率为35%;同一葡萄品种的叶片与叶柄诱导愈伤组织的频率基本相同,而红地球外植体诱导愈伤组织的频率高于无核白;(2)不定芽的诱导再生以1/2MS+BA0.5mg/L+NAA0.05mg/L+CH500mg/L+蔗糖30g/L培养基最佳,平均诱导率达35.4%;叶柄来源的愈伤组织诱导不定芽的频率高于叶片愈伤组织;(3)根系的诱导以1/2MS+KT0.5mg/L+IBA1.0mg/L+AC2g/L+蔗糖15g/L培养基最佳,无核白和红地球来源的不定芽诱导生根频率基本相同,都在80%以上。     

激动素和萘乙酸不同浓度配比对大豆组织培养器官分化的影响

本文报道激动素(KT)和萘乙酸(NAA)不同浓度配比对大豆上胚轴和小真叶外植体愈伤组织器官分化的影响以及对分化成苗与未分化愈伤组织过氧化物酶活性的分析。 B_5基本培养基附加KT1+NAA 0.2毫克/升(5:1)对大豆上胚轴和小真叶外植体愈伤组织再生植株较适宜,增加NAA的比例抑制芽的分化,增加KT的比例抑制根的分化,都不利于再生植株。 过氧化物酶活性,分化成苗愈伤组织都较未分化愈伤组织的高。     

台湾释迦的离体培养与植株再生

选取台湾释迦实生苗的不同部位为外植体进行离体培养与植株再生研究。结果表明：诱导台湾释迦愈伤组织的最佳外植体为下胚轴,最适愈伤组织诱导培养基为MS＋6．BA0．5mg／L＋2,4．D2mg／L;愈伤组织分化培养基为MS＋6．BA2mg／L＋NAA0．1mg／L;增殖培养基为MS＋6-BA0．5mg／L＋NAA0．1mg／L;生根培养基为1/2MS＋NAA0．2mg／L。     

银合欢组织培养研究初报

以银合欢(Leucaena leucocephla(Lamarck)de Wit)无菌实生苗子叶和胚轴切段为外植体,以MS为基本培养基,研究不同BA和NAA浓度组合对银合欢组织培养效果的影响。结果表明：愈伤组织诱导培养中,以子叶的培养反应性最好,其愈伤组织诱导率在各种组合中都达到100 %,其中以附加0.1 mg/L NAA和2.5-7.0 mg/L BA效果最好;胚轴在添加0.1 mg/L NAA及3.0-4.5 mg/L BA的MS培养基上培养时愈伤组织诱导率较高。子叶愈伤组织在MS+3.0 mg/L     

双低油菜品种组织培养的反应

在有激素培养基中萌发的油菜种苗的子叶大而厚、根少而短、下胚轴粗短,并有少数愈伤组织出现。2,4—D1～3mg/1均能诱导愈伤组织形成,添加0.1～1mg/16BA有利于愈伤组织的分化培养。子叶愈伤组织诱导率高于下胚轴,三个品种中,双低油菜DSV—SR—50的诱导率最高。来自激素萌发培养基的下胚轴的愈伤组织发生早、发展快、诱导频率高,并有直接分化出芽的。愈伤组织在含有IAA1mg/l和6BA1～7mg/l的B5培养基中都能分化出芽,但以添加6BA3～5mg/l对频率最高。小塔的愈伤组织分化频率最高为45.65％,以下为DSV—SR—5034.32％,Liglando 22.79％。并讨论了前期培养基和材料基因型与愈伤组织诱导分化的问题。     

亚麻转基因植株的再生及生根培养的研究

本试验以亚麻幼苗的下胚轴为外植体,利用抗除草剂Basta的目的基因和G USINT基因,采用农杆菌介导法进行了亚麻转基因过程中植株再生及生根适宜培养基的筛选试验.经试验得出:在附加少量BA和NAA的Ms培养基上愈伤组织的再分化率可达31.8%～40 .2%.经GUS基因检测在脱菌后3天亚麻下胚轴初步形成的愈伤组织的转化率可达72.2%;四周后的转化率为25%;再生植株的转化率为20%.在1/2Ms培养基中附加0.001mg/L NAA 可使再生植株的生根率达到87.4%.通过试验初步建立起了根瘤农杆菌介导法亚麻转基因系统.     

亚麻转基因植株的再生及生根培养的研究

本试验以亚麻幼苗的下胚轴为外植体 ,利用抗除草剂 Basta的目的基因和 GUSINT基因 ,采用农杆菌介导法进行了亚麻转基因过程中植株再生及生根适宜培养基的筛选试验。经试验得出 :在附加少量 BA和 NAA的 Ms培养基上愈伤组织的再分化率可达31.8%～ 40 .2 %。经 GUS基因检测在脱菌后 3天亚麻下胚轴初步形成的愈伤组织的转化率可达 72 .2 %;四周后的转化率为 2 5 %;再生植株的转化率为 2 0 %。在 1/2 Ms培养基中附加 0 .0 0 1mg/L NAA可使再生植株的生根率达到 87.4%。通过试验初步建立起了根瘤农杆菌介导法亚麻转基因系统。     

‘黄天霸’百合花器官愈伤组织诱导及植株再生

以‘黄天霸’百合花器官为外植体,采用正交试验,进行愈伤组织诱导及再分化研究,获得再生植株。结果表明,‘黄天霸’百合花器官的不同部位,其分化能力不同,出愈率由高到低依次是花丝>花柱>子房>花瓣>花药,花丝是较适宜诱导产生愈伤组织的外植体。花丝愈伤组织诱导的适宜培养基为MS+0.5 mg/L 6-BA+0.3 mg/L NAA+0.3 mg/L 2,4-D,出愈率为69.56％,适宜愈伤组织增殖培养基为MS+0.5 mg/L 6-BA+0.5 mg/L NAA;适宜芽分化的培养基为MS+0.6 mg/L 6-BA+0.6 mg/L NAA,芽诱导率达100％;最适生根培养基为MS+0.1 mg/L NAA,生根率达100％;试管苗移栽于草炭 ∶ 蛭石 ∶ 珍珠岩 ∶ 园土 ∶ 河沙=2 ∶ 1 ∶ 1 ∶ 1 ∶ 1的基质中,成活率达92％。     

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).