不同低温处理对油棕叶片解剖结构的影响

以2年生的油棕幼苗为材料,根据温度的日变化规律,设置4个不同的最低温度处理,分别为CK(自然温度处理),16℃(T1处理)、12℃(T2处理)、8℃(T3处理),处理20 d后对其在不同低温处理下叶片的伤害情况、解剖结构的变化进行了分析研究。结果表明:随着处理温度的降低,叶片受伤害情况越来越严重。其中油棕叶片总厚度和组织疏松度(SR)2个叶片结构指标在不同低温处理下变化明显,可作为油棕抗寒种质鉴定的结构指标,为培育适合在中国栽培的抗寒油棕品种提供理论指导。     

油棕种质资源评价研究的现状及展望

高产、抗寒和抗旱是我国油棕育种的重要目标。本文综述了油棕种质资源评价研究方面的进展，尤其是在高产、抗寒和抗旱鉴定评价方面；提出了目前油棕资源评价中存在的问题，并对未来的研究方向进行了展望，以期为培育适合我国栽培的高产、抗寒和抗旱品种提供参考。     

云南大理油棕自交子一代对低温胁迫的生理响应及抗寒性评价

低温是限制油棕生长发育和产量的重要影响因子,探究低温条件下油棕的生理响应机制,为油棕耐寒种质资源的选育及推广提供理论依据.以云南大理抗寒高产油棕成龄树的自交F1代有性系苗木为试验材料,在4℃低温胁迫下处理0(对照)、1、3、5 d,根据叶片寒害程度及其恢复生长情况将其划分为4个寒害等级,即1级(无)、2级(轻)、3级(...     

油棕幼苗对低温胁迫的生理响应及其抗寒力评价

在0～15℃温度范围内，测定10个油棕种质的叶绿素、游离脯氨酸、可溶性蛋白、可溶性糖、丙二醛含量及相对电导率等与抗寒性大小有关的生理生化指标，利用SAS8.1统计主成分分析法，对10份油棕种质的抗寒能力进行综合评价，结果表明：(1)丙二醛和相对电导率是反映油棕低温胁迫的最重要指标，其次是叶绿素和脯氨酸含量，再次为可溶性糖和蛋白质含量。(2)主成分分析结果表明，低温胁迫处理的10个油棕种质的综合抗寒力为：RYL38＞RYL36＞RYL31＞RYL33＞RYL39＞RYL34＞RYL32＞RYL37＞RYL40＞RYL35。     

低温胁迫下不同浓度ABA对4个油棕新品种幼苗生理特性的影响

探讨低温胁迫下不同品种油棕幼苗ABA合成酶基因NCED3表达特性及不同浓度ABA对其幼苗生长和生理的影响,为提高不同品种油棕幼苗抗寒能力提供理论依据。以油棕新品种Ni、C×N、B×E、D×N为材料,对其进行低温胁迫处理（15、10、5 ℃,5 d）,利用实时荧光定量PCR（qPCR）检测4种油棕幼苗的NCED3基因表达特性;然后,10 ℃低温胁迫下对4种油棕幼苗外施不同浓度ABA（50~300 μmol/L ABA）,测定其可溶性蛋白、可溶性糖、脯氨酸含量和超氧化物歧化酶（SOD）及过氧化物酶（POD）活性等生理指标。结果表明,低温胁迫可触发4种油棕幼苗ABA合成酶基因NCED3的过量表达,外施50~300 μmol/L ABA均降低幼苗质膜透性和SOD酶活性,抑制MDA和H₂O₂含量上升,缓解低温胁迫引起的膜脂过氧化,提高可溶性蛋白、可溶性糖含量和POD活性,进而提高油棕幼苗抗寒性。4个品种中,B×E材料的耐寒能力较强。     

低温胁迫下油棕幼苗的某些生理生化特性

观测盆栽油棕幼苗在低温胁迫下的一些生理指标变化.结果表明,随着温度的下降和低温胁迫时间的延长,油棕幼苗叶片相对含水量和可溶性蛋白含量不断下降;可溶性糖含量、脯氨酸含量、束缚水/自由水的比值、SOD、POD、CAT活性先上升而后下降;MDA含量和相对电导率不断增大;油棕幼苗正常生长的临界温度约为10℃,其可忍受低温的温度范围约为4～7℃;抗寒性弱的油棕幼苗品种在4℃下可忍受6 d左右.     

油菜抗寒性生理生化机制及基因工程研究进展

低温是限制油菜生长和分布的一种非生物胁迫因素。在国内外大量研究成果的基础上,系统阐述了油菜在低温胁迫下生物膜、酶活性、渗透调节物质等生理生化方面的适应性变化及其与抗寒性的关系,并对油菜抗寒基因工程方面的研究进展作了综述；提出了在油菜抗寒性研究中存在的问题，并对未来工作重点进行了展望。     

海南岛气候与油棕种植

本文对马来西亚与海南岛的崖县、儋县、定安等地的油棕单产作了比较,以马来西亚最高,其余依次递减,究其原因主要是海南各地有不同程度低温和台风为害所致。目前,在气温和台风难于人为控制的情况下,欲求海南油棕高产,只能择地而种。按油棕生态要求,可将海南划分为5个区:西南部干热区(崖县、乐东、东方等地),是海南种油棕最好的地方;东南沿海风热区(陵水、万宁等地),油棕达中年后易受风害,经济寿命短;西部旱寒区(儋县等地),油棕产量低于前两区,但高于其他油料作物;中部重寒区(通什、琼中、澄迈等地),种植油棕要冒风险;东北部风寒区(琼山、文昌等地),种植油棕较危险。     

我国橡胶树抗寒生理研究的进展

零上低温寒害是我国橡胶树北移种植的主要限制因子。自本世纪50年代起,我国开始研究橡胶树抗寒生理学。研究的领域包括寒害成因、抗寒力的本质、提高抗寒力的措施以及鉴定抗寒力的方法。本文着重分析橡胶树寒害成因和抗寒生理—生化变化过程,并对今后橡胶树抗寒生理的研究提出初步设想。     

冬小麦抗寒性鉴定的低温处理方式和鉴定指标的研究

为了筛选冬小麦抗寒性鉴定的低温处理方式和鉴定指标,以冬小麦强抗寒品种东农冬麦1号、弱抗寒品种济麦22和不抗寒品种中国春为试验材料,设室内快速低温、室内缓慢低温和田间种植三种处理,测定和分析了不同处理下小麦叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性及抗坏血酸(ASA)、谷胱甘肽(GSH)、丙二醛(MDA)、过氧化氢(H2O2)含量.结果表明,与室内缓慢低温处理相比,室内快速低温处理下小麦各项指标较接近田间种植处理,且与田间种植处理相关性较显著.低温下抗寒品种的H2O2及MDA含量显著低于弱抗寒品种和不抗寒品种,SOD活性和ASA含量与H2O2含量呈极显著负相关.因此,室内快速低温处理结合SOD活性及ASA、H2O2和MDA含量分析可以进行小麦品种抗寒性鉴定.     

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).