小麦花粉的离体萌发研究

为筛选适合小麦花粉离体萌发的培养基配方,建立有效的离体萌发方法体系,以小麦品种西农1376为材料研究了不同浓度组合的蔗糖和聚乙二醇4000(PEG4000)在小麦花粉离体萌发中的作用,在此基础上又研究了硼酸(H3BO3)、钙离子(Ca2 )以及生理活性类物质维生素B1(VB1)对小麦花粉离体萌发的影响.结果表明:(1)一定浓度的蔗糖、PEG4000、H3BO3、Ca2 对小麦花粉的萌发有明显的促进作用,而VB1对花粉萌发的效果不明显;(2)18%蔗糖 9% PEG4000 2 g/L Ca(NO3)2·4H2O 60 mg/L H3BO3的培养基成分比较适合小麦花粉的离体萌发;(3)在28℃的条件下培养50 min最适合小麦花粉的萌发及观察与统计;(4)在上述培养基和培养条件下直接采用本研究设计的离心管封闭培养方法可使西农1376的花粉萌发率达到70%以上.     

牛角瓜花粉萌发及花粉管生长研究

运用方差分析、多重比较、正交实验和极差分析方法,对牛角瓜花粉的萌发和花粉管生长进行研究,结果表明,培养基内硼酸、硝酸钙、蔗糖、硫酸镁在一定浓度范围内,对花粉萌发及花粉管生长起促进作用,但浓度过高或过低时,则有抑制作用;钾对花粉萌发及花粉管生长影响不显著;蔗糖和硝酸钙对牛角瓜花粉萌发有显著影响,蔗糖和硫酸镁对牛角瓜花粉管生长有显著影响;牛角瓜最适花粉液体培养基为：15% 蔗糖＋350 mg/L Ca(NO3)2?4H2O＋60 mg/L H3BO3＋150 mg/L MgSO4?7H2O;在30～35℃温度条件下,牛角瓜花粉块萌发和花粉管生长最好。     

3份胡椒属种质花粉离体萌发研究

以海南蒟、大叶蒟和球穗胡椒的花粉为材料,研究了不同培养基和采样时间对花粉萌发率的影响。结果表明：3种胡椒种质花粉的最佳萌发条件分别为100 g/L蔗糖＋100 mg/L硼酸+600 mg/L Ca(NO3)2、100 g/L蔗糖＋100 mg/L硼酸＋300 mg/L Ca(NO3)2和100 g/L蔗糖＋200 mg/L硼酸＋300 mg/L Ca(NO3)2。ME3培养基抑制海南蒟和球穗胡椒花粉萌发,蔗糖、硼酸和Ca2+的协同作用可以提高胡椒花粉萌发率,硼酸的浓度需要控制在一定范围内(≤200mg/L     

柱花草花粉活力的测定方法

利用6种常用花粉活力测定方法对柱花草花粉活力进行测定，并筛选出各方法的最佳配方。结果表明：以离体萌发法为最佳，最适培养基：10%蔗糖、10% PEG-6000(聚乙二醇)、0.01% H3BO3、0.03% CaCl2·2H2O、0.01% KNO3，pH 6.5，柱花草花粉在该培养基上30℃条件下培养10 min，萌发率可达84.03%。0.5% I2＋1.5% KI的碘-碘化钾染色效果好，色差明显，较离体萌发法测定值偏高，但差异不显著，可选作简单快速测定法；FDA(荧光素二醋酸脂)染色法、醋酸洋红染色     

大麻花粉萌发的影响因子及花粉储存的初步研究

利用不同蔗糖浓度、硼酸浓度、Ca2 浓度、温度对6个不同熟性的大麻品种的花粉进行萌发研究,结果表明:大麻花粉培养以15%蔗糖 80mg/L硼酸的液体培养基时花粉的萌发率最高,花粉管的生长速度则以硼酸浓度为20mg/L时最快,加入Ca2 则抑制花粉萌发,培养温度25℃最好。花粉储存中,常温下,未干燥的大麻花粉生活力只能保持3d(天);干燥、密封后在1—4℃条件下花粉活力最多可保持30d;干燥、密封后在-20℃条件下,储存120d后的花粉还有较高的萌发率(34%)。     

马铃薯花粉的离体萌发

选出普遍适合马铃薯花粉萌发的液体培养基 :10 %蔗糖 + 0 0 2 %CaCl2 + 0 0 2 %H3BO3+ 0 0 2 %MgSO4 ·7H2 O + 0 0 1%KNO3,在此培养基上花粉的最高萌发率达 78 1%。培养基中加入0 4 %的NaCl能显著提高萌发速度但并无促进萌发的作用 ;5～ 7d的低温预处理能显著提高花粉萌发率和萌发的同步性     

甘蔗花粉离体萌发研究

为筛选适宜栽培种甘蔗花粉离体萌发的培养基配方,建立有效的离体萌发体系,以糖用甘蔗主栽品种ROC22花粉为材料,通过单因素试验探索满足甘蔗花粉离体萌发的基本条件,然后利用L₁₆(4 ⁵)正交试验,寻求甘蔗花粉离体萌发的最适宜培养基配方,在此基础上进一步探讨不同温度对甘蔗花粉萌发的影响。在单因素试验中,培养基以刚好凝固时为最佳。蔗糖、硼酸和硝酸钙在一定范围内对甘蔗花粉萌发起促进作用,超过一定浓度则起抑制作用。硫酸镁作用不稳定,硝酸钾影响较小。正交试验中,蔗糖对甘蔗花粉离体萌发率和花粉管生长速率影响最大,呈显著水平,硼酸次之,硫酸镁影响最小。花粉萌发的适宜温度为30 ℃,萌发率和花粉管长度分别为89.83%和143.03 μm。200 g/L蔗糖+400 mg/L硼酸+100 mg/L硝酸钙+400 mg/L硫酸镁+1 g/L琼脂,在30 ℃下培养花粉萌发率最高,花粉管生长状态良好,这种方法可快速有效鉴定不同甘蔗花粉活力差异。     

大麻花粉萌发的影响因子及花粉储存的初步研究

利用不同蔗糖浓度、硼酸浓度、Ca2 浓度、温度对6个不同熟性的大庥品种的花粉进行萌发研究,结果表明:大麻花粉培养以15%蔗糖 80 mg/L硼酸的液体培养基时花粉的萌发率最高.花粉管的生长速度则以硼酸浓度为20mg/L时最快,加入Ca2 则抑制花粉萌发,培养温度25℃最好.花粉储存中,常温下,未干燥的大麻花粉生活力只能保持3d(天);干燥、密封后在1-4℃条件下花粉活力最多可保持30d;干燥、密封后在-20℃条件下,储存120d后的花粉还有较高的萌发率(34%).     

响应面法优化金银忍冬花粉离体萌发培养基组分

目的以优化金银忍冬花粉离体萌发的培养基组分。方法以盛花期新鲜花粉为材料,采用花粉离体萌发方法,在单因素试验的基础上,通过响应面法优化培养基组分。结果金银忍冬花粉离体萌发的最佳培养基组分为蔗糖质量浓度为400g/L、硼酸质量浓度为127.23mg/L、2,4-D质量浓度为75.00mg/L,在此培养基组分条件下,金银忍冬花粉萌发率的预测值为90.24%,验证萌发率为89.65%。结论利用响应面分析法可得到理论最佳培养基组分,验证结果表明该方法科学、高效。     

不同培养基组分对黄檗花粉离体萌发的影响

以期筛选出黄檗花粉离体萌发最适宜的培养基,以新鲜的黄檗花粉为研究对象,采用花粉离体培养的方法,通过L_9(3~4)正交试验设计,探究蔗糖、硼酸和硝酸钙对黄檗花粉离体萌发的影响。结果表明:蔗糖对黄檗花粉萌发率的影响最大,而对花粉管长度无显著影响;硼酸对花粉管长度的影响最大,而对萌发率无显著影响;硝酸钙对二者均有影响。黄檗花粉离体萌发最适宜的培养基为:10%蔗糖+0.008%硼酸+0.02%硝酸钙。     

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.