不同施氮量对甜菜的产质量效应研究

施用氮肥可显著促进甜菜叶丛生长，施氮量与产量和产糖量之间均呈二次曲线相关，与块根含糖率呈极显著的负相关，过量施用氮肥不利于甜菜干物质的合理分配，造成产量降低，产糖量减少。甜菜植株含氮量与施氮量呈显著正相关，地上部钾含量随施氮量增加而减少，而地下部钾含量随氮量增加显著增加。本试验中甜菜的合理施氮量为１２０ｋｇ／ｈｍ＾２。     

河套地区甜菜含糖与相关因素的调查

调查结果表明,甜菜收获前割擗叶子、过量施氮肥和低密度种植是影响河套地区甜菜糖分的主要因素,可降低含糖3.0～4.0锤度;其次是提前收获,可降低含糖约2.0锤度。该区有利于提高甜菜含糖的适宜保苗密度为6.7～7.5万株/hm2,种肥适宜用量为:氮30～75kg/hm2,磷60～120kg/hm2,钾22.5kg/hm2;追肥适宜用量为:氮120～180kg/hm2,磷45kg/hm2,钾60kg/hm2。同时要注意选用优良品种,它是影响甜菜含糖的内在因素。     

施氮量与甜菜产量的形成

试验表明,施氮量与甜菜叶面积、光合势、叶绿素含量均呈显著正相关,与净光合生产率呈负相关,故高氮处理,因叶面积指数和光合势过大,净光合生产率低,不利于产量形成;根产量与施氮量呈二次曲线相关,含糖率与施氮量呈负相关,高氮处理T/R值明显增加,导致根产量和含糖率降低;随施氮量增加,造蜜性物质增加,块根品质降低;本试验以施120kg/ba氮产糖量最高,过量施氮降低产糖量.     

不同施钾水平与甜菜产质量关系的研究

在不同施钾水平下对甜菜块根产量、含糖率及产糖量进行了研究。其结果表明:随着施钾水平的提高,甜菜块根产量、含糖率及产糖量增加,并且均与施钾水平呈显著正相关。施钾水平在每公顷K2O150kg以上时,处理间块根产量差异不显著;施钾水平在每公顷K2O100kg以上时,处理间含糖率及产糖量差异不显著。在土壤含钾量较高的黑龙江省南部黑土地区,生产上钾肥用量宜控制在每公顷K2O100～150kg。     

甜菜施锌效应的研究

试验结果表明,锌营养具有提高甜菜幼苗抗坏血酸氧化酶活性,增加全生育期叶绿素合量和净光合率,促进干物质积累,显著提高根含糖率等效应。亩施1kg硫酸锌作种肥在黑土地较对照可提高根含糖率0.76度,提高产糖量2.9％;在碳酸盐黑土地可提高根含糖率1.1度,增产块根7.1％,产糖量提高15.4％。     

氮素运筹对干旱区滴灌甜菜生长的影响

选取Beta356甜菜品种为试验材料,以不施氮素处理(N1)为对照,设置3种氮素运筹模式,即分别在叶丛快速增长期、块根膨大期和糖分积累期施用3种比例的氮素(60∶30∶10、50∶30∶20、40∶40∶20),氮素总量为585 kg/hm~2,各处理施氮量保持一致,测定叶片和块根生长速率、叶面积指数以及甜菜块根产量。以探讨氮素运筹对甜菜生长和产糖量的影响,为干旱区滴灌甜菜高产高糖氮素管理提供参考。结果表明,与对照相比,施氮可以减缓甜菜叶片的衰老速率。滴灌甜菜块根膨大期叶片生长以老叶为主,氮素运筹不改变老叶的主体地位,但是对叶片生长速率具有一定的调控作用。块根膨大期老叶面积及其叶面积日增长量与甜菜块根产量和含糖率显著正相关,新叶面积与甜菜块根产量显著正相关,与块根含糖率显著负相关。氮素运筹对块根生长无显著影响,根长、根宽和块根维管束环数在块根膨大中期与块根产量显著正相关,在块根膨大后期与块根含糖率显著正相关。块根膨大期的老叶面积和块根体积可用于衡量甜菜产糖量,新叶面积可用于衡量块根含糖率。通过氮素运筹保证块根膨大期老叶叶面积同时适当控制新叶发生速率,促进根系发育,有利于提高滴灌甜菜块根产量和含糖率。     

甜菜平衡施肥技术研究

本试验运用一次回归正交设计法,对氮、磷、钾、锌4种肥料与糖用甜菜块根产量、含糖率及产糖量的关系进行了综合分析.结果表明1)4种肥料对甜菜块根产量均有极显著的增产作用.对块根产量贡献依次为N＞K2O＞P2O5＞Zn;2)对含糖率的作用大小不同.其中,增施钾肥有助于提高含糖率,氮肥与磷肥对含糖率呈负效应,锌肥效果不明显.对含糖率贡献依次为K2O＞Zn＞P2O5＞N;3)对产糖量的作用主要表现在钾肥与锌肥有极显著的正效应,氮肥与磷肥作用不明显.对产糖量贡献依次为K2O＞Zn＞P2O5＞N.因此,综合评价平衡施肥技术为每公顷施纯N240.00kg、P2O5240.00kg、K2O168.75kg、Zn33.75kg,对增加甜菜块根产量、提高含糖率及产糖量效果较优.     

甜菜工艺有害物质的遗传变异与选择

利用３年品种比较试验资料进行了甜菜工艺有害物质钾、钠、氨基氮含量的遗传力、变异系数、遗传进度以及３性状和根产量、含糖率相关系数等遗传参数的估算。结果广义遗传力的大小顺序为Ｋ＞Ｎａ＞ＡｍＮ、遗传变异系数的大小顺序为Ｎａ＞ＡｍＮ＞Ｋ。以５％的选择强度进行选择，Ｋ、Ｎａ、ＡｍＮ含量可分别降低１．３１、１．１１和０．６２ｍｍｏｌ／ｇ甜菜。Ｋ、Ｎａ、ＡｍＮ含量与根产量的遗传相关为正相关，与含糖率呈负相关．降低工艺有害物质的含量，可选育出单位面积可回收糖量高的甜菜品种。     

施用氮肥对甜菜产质量的影响

试验结果表明,随着施氮量的增加,甜菜根产量的增加趋势是平缓的,当施氮量达到150kg/hm2,根产量不再增加;随施氮量的增加,茎叶产量明显增加,茎叶重与根重比也增大,同时糖浸出液中钾、钠等不纯性物质的含量增加,导致含糖率下降,产糖量降低。     

甜菜的杂种优势分析

本文通过对甜菜多粒雄性不育系测交组合试验所调查的甜菜4个主要产质量性状杂种优势分析,表明,杂种优势在性状之间和组合之间的差异是明显的,其优势程度依次为:产糖量>根产量>褐斑病病情>含糖率,而优势的稳定性则为,含糖率>褐斑病病情>根产量>产糖量。各性状优势间的相关表现为,根产量及含糖率与产糖量是极显著的正相关;根产量及含糖率与褐斑病病情均为负相关;根产量与含糖率为正相关。含糖率和产糖量两个性状明显回归于中亲和低亲,根产量明显回归于中亲和高亲。因此,通过利用杂种优势是可以选育出既丰产又高糖且抗病性强的品种。     

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).