蔗糖、激素及基因型对小麦花药培养的影响

为进一步提高小麦的花药培养效率，以6个普通小麦杂交组合的F1群体为材料，研究了小麦花药离体培养中不同蔗糖浓度和不同激素组合以及基因型对小麦花药培养特性的影响。结果表明，蔗糖浓度对小麦花药愈伤组织的诱导有显著影响，最适蔗糖浓度为100g／L；不同激素组合对小麦花药愈伤组织的再分化频率也有影响，3个基因型均以W14附加1.5mg／LKT＋0．5mg／L IAA激素组合的绿苗分化率最高（分别为59．09％、48％和57．14％），显著高于W14附加1.5mg／LKT及1.5mg／LKT＋0．1mg／L NAA的绿苗分化率。研究还表明，不同基因型小麦花药组织的脱分化特性和再分化特性不同；同一基因型小麦花药愈伤组织的诱导和再分化之间存在显著的正相关。     

玉米花药培养影响因素研究

采用36种玉米基因型材料,研究了基因型、培养基、接种前冷藏以及田间早期对雄穗注射一定浓度的2,4-D和在接种前用一定浓度的2,4-D浸泡雄穗对出愈率的影响。结果表明:在玉米培养基 N6(微量元素) 2,4-D2mg/L KT2mg/L 水解酪蛋白(CH)500mg/L 活性炭0.2% 糖12% 琼脂6.5g的诱导培养基中,36个基因型玉米中只有7个基因型能诱导出愈伤组织。其中博丰5号在接种前用4℃冷藏7d出愈率可增加3.71%;SB304在13～14叶期用2,4-D注射雄穗能有效提高其出愈率;金象4号雄穗在接种前用2,4-D浸泡,随着2,4-D浓度的增加或浸泡时间的加长,其出愈率都在增加。     

白菜游离小孢子培养高频胚诱导技术体系优化

为优化白菜游离小孢子培养高频胚诱导技术体系,以20个不同基因型白菜栽培品种为供试材料,对影响白菜游离小孢子胚诱导和植株再生因素进行研究。结果表明:有14个基因型产生了小孢子胚,不同基因型之间胚诱导率差异显著,表明基因型是影响小孢子胚发生的主要因素;通过对白菜游离小孢子培养高频胚诱导技术体系的优化,胚诱导率明显提高,最优组合为盛花期取蕾;花瓣长与花药长比为0.5~0.75;4℃低温预处理1 d;150 g/L蔗糖的NLN培养基33℃高温热激2 d,重新离心更换130 g/L蔗糖的NLN培养;激素最优组合为6-BA0.1 mg/L、NAA 0.5 mg/L;在培养基中添加活性炭有利于胚的形成,最佳浓度为0.5 g/L。     

花生花药培养的初步研究

本研究对14个基因型花生的花药进行了培养。结果表明,花药愈伤组织诱导率受基因型、花蕾长度、蔗糖浓度和基本培养基等因素的影响。小孢子单核期为适宜的诱导时期,培养基以6％～13％蔗糖浓度的B5培养基较好;基因型不同,愈伤组织诱导的最适基本培养基不同,在接种的14个基因型中,11个基因型(占78．57％)在B5培养基上产生较高的愈伤组织诱导率,变幅为62．75％～97．8％。在附加4．0mg／L 6-BA、0．5mg／L TDZ和0．4mg／L AA的改良MS养基上,基因型19获得了11．63％的体胚分化率。     

基因型和AgNO3对甘蓝型油菜子叶外植体植株再生的影响

以甘蓝型油菜无菌苗子叶为外植体,接种于不同配比激素组合的培养基,研究AgNO3及基因型对油菜子叶外植体再生频率的影响.通过对芽苗分化率的方差分析表明,基因型、AgNO3及基因型与AgNO3互作对植株再生的影响均达到极显著水平,其影响程度为基因型＞AgNO3＞基因型×AgNO3.诱导芽苗分化的最佳培养基为MS+4mg/L BA+0.3mg/L NAA+5～10mg/L AgNO3.     

超级黑糯玉米花药单倍体诱导培养基的筛选

通过多因素正交实验发现,基本培养基种类和激素配比是影响超级黑糯玉米花药培养的重要因素,并确定N₆和正14两种基本培养基较适合该类玉米花培诱导。进一步优化培养基的研究表明,两种培养基对该类玉米花药诱导效果最好。玉米花药培养对基因型依赖很大,且不同基因型的玉米花药诱导需要的基本培养基也不同。超级黑糯玉米花培较适合的培养基是N₆和正14的液体和半固体两种培养基。     

冬瓜组培再生体系的初步建立

以冬瓜子叶节为试材，探讨培养条件、不同基因型及诱导、伸长和生根培养基不同激素类型与配比情况，初步建立了冬瓜组培再生体系。结果表明：种子剥皮消毒后，在纸桥培养基暗培养发芽率较高，且节约成本；以暗培养5 d、见光培养1 d刚转为淡绿色的闭合子叶，其不定芽诱导率最高，约75％；以13个不同基因型冬瓜子叶节为外植体，接种至不同激素浓度组合的培养基上，筛选出分化率较高的品种B214，其不定芽再生率可达到79.2％，诱导分化培养基为MS+4.0 mg/L 6-BA+0.4 mg/L NAA，伸长培养基为MS+1.0     

糖液预处理对提高玉米花培诱导率的研究

对不同材料用蔗糖溶液预处理花药,使之产生质壁分离,再接种于不同蔗糖浓度的培养基上.探讨了玉米花药胚状体(愈伤组织)产生情况,指出胚状体(愈伤组织)与基因型关系很大,用25%浓度蔗糖预处理花药6～7min及培养基中加15%浓度蔗糖诱导频率最高。     

岗松扦插繁殖试验初报

以岗松枝条为试验材料,分别就插穗部位的选择不同激素种类及浓度处理对扦插成活率的影响进行了试验研究。初步结果表明:插穗选1-2年生枝条的基部或中部茎段;激素种类及浓度处理选用500 mg/L的NAA或IBA浸泡30 min,能极显著提高扦插成活率。     

不同处理方法对赪桐种子萌发的影响

以发芽率、平均发芽时间为指标，研究不同清水浸泡时间、热水处理、烘焙处理、破壳处理、激素处理和低温层积等因素对赪桐种子萌发的影响。结果表明：采用破壳处理方法能极显著地提高种子发芽率，其发芽率达到92%；在不同烘焙处理中，6 h处理为最佳，其发芽率达74%；在不同的浸泡处理中，以自然水浸泡72 h处理为最佳，其发芽率达60%；在不同播种深度处理中，以3 cm播种处理为最佳，其发芽率达60%；激素处理能明显提高种子的发芽率，浓度为30 mg/L的萘乙酸、25 mg/L赤霉素、30 mg/L的6-BA溶液的浸泡处     

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).