培养条件对甘蓝型黄籽油菜下胚轴的再生影响

以甘蓝型黄籽油菜GH01的下胚轴为材料，研究影响外植体芽再生的因素。试验结果表明，苗龄、预培养基的激素浓度和预培养时间、分化培养基等对芽再生频率均有较大影响。8d苗龄的下胚轴置MS 1．5mg／L2，4-D 0．1mg／L6-BA培养基预培养4d后，转分化培养基MS 4．0mg／L6-BA 0．05mg／LNAA 5．0mg／LAgNO3 0．6mg,／LGA3培养，可获得较高的芽再生频率。添加5mg／LAgNO3处理可防止外植体褐化并有利于芽分化；0．6mg／L GA3处理可促进胚状体形成，提高芽再生频率。GH01最高芽再生频率为40．50％。     

甘蓝型油菜下胚轴培养和高频率芽再生技术的研究

以１１个甘蓝型油菜品种（系）的下胚轴为外植体,研究影响下胚轴细胞再生的若干因素。结果表明,用附加２,４－Ｄ的培养基对下胚轴切段进行短时间的预培养可显著提高细胞的生长和分化能力,使芽再生率达９０％以上;ＡｇＮＯ３对细胞的生长有很大的促进作用;丝氨酸和谷氨酰胺的有益效应不明显;下胚轴的上端比下端产芽早,但两者产芽率差异不显著;不同的基因型对同一培养条件反应不同,芽分化频率差异很大。     

6-BA和AgNO3对芥菜型油菜下胚轴芽再生的影响

以芥菜型油菜品种Brown mustard的下胚轴为外植体,接种于不同配比6-苄基腺嘌呤（6-BA）和硝酸银（AgNO3）组合的分化培养基中,研究6-BA和AgNO3对芥菜型油菜下胚轴芽再生的影响。结果表明分化培养基中含3 mg/L 6-BA＋5 mg/L AgNO3时出芽率最高,出芽率达到58.33%,芽丛数平均为1.73。     

亚麻体细胞无性系的建立及其植株再生

以亚麻无菌苗（7—10天培养）切取的茎尖和下胚轴作为外植株，分别接种于N6、B5基础培养基，均附加IAA4mg／L、KT2mg／L和LH200mg／L，经过四个星期的离体培养，获得具备不定苗发生能力的愈伤组织，诱导率平均达94．2％。然后把它们转移至继代培养基中进行再分化培养，培养得到绿苗及胚性意伤组织，分化频率平均达6．3倍。切取下的绿苗植于改良后的B5培养基上进行生极培养，生根率达90％以上。对成活的204株再生植株进行三个世代的连续观察，获得雄性不育体、感病、矮杆等广泛的性状变异。     

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％。     

大豆不同外植体植株再生的研究

采用不同大豆品种的下胚轴、上胚轴、小真叶和幼胚作外植体进行植株再生的研究。结果表明汾豆３３号诱导植株再生率最高;诱导频率依次为下胚轴＞上胚轴＞小真叶＞幼胚;下胚轴在Ｂ５＋ＮＡＡ０．３ｍｇ／Ｌ＋ＫＴ１ｍｇ／Ｌ培养基上可诱导出愈伤组织并直接分化成苗,植株再生频率为３４％,最高达５０％。获得大豆高频率再生植株,收到较饱满的种子。     

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。     

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%。     

龙眼胚性悬浮细胞原生质体培养及其体胚发生再生植株

以“红核子”、“东壁”、“十二月龙眼”等龙眼品种的胚性悬浮细胞为起始材料分离原生质体,采用液体浅层培养、包埋悬浮培养等方式,进行原生质体培养与植株再生研究。研究结果表明,海藻酸钙包埋悬浮振荡培养(50r/min)是龙眼悬浮细胞原生质体培养的适宜培养方式,在含有多种生长调节剂的改良MS培养基(MP6)上,再生小克隆的形成频率可高达5%;采用龙眼胚性愈伤组织体胚诱导、成熟和萌发的优化方案,原生质体再生小克隆分化子叶形胚状体的频率达100%,萌发植株的频率一般大于45%。      

播娘蒿高频率再生植株因素的研究

以播娘蒿子叶、子叶柄和下胚轴为外植体，研究不同外植体、激素组合以及硝酸银对播娘蒿再生频率的影响。结果表明：外植体、激素以及硝酸银的影响都非常显著；最佳外植体为下胚轴；最佳激素组合为6－BA（2．0mg/L) NAA(0.5mg/L);附加AgNO3(1.7mg/L)可使下胚轴再生频率提高63．42％。诱导生根的最佳培养基为1／2MS＋NAA（0．5mg/L) IBA(0.5mg/L)。     

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).