化学药物诱导玉米孤雌生殖研究初报

采用4种药物配方、3种使用方法对不同类型玉米材料孤雌生殖诱导效果进行了试验,结果表明4种药物配方以2%二甲基亚砜诱导效果最好,其结实穗率是对照的2.8倍.3种使用方法间其诱导结果差异不大,以注射效果略好.不同类型材料间诱导结果显著不同,大小顺序为玉米群体＞玉米杂交种＞育种中间材料＞自交系,同类材料不同品系间的诱导结果也大不一样,与材料的基因型或纯合程度有关。     

除草剂诱导玉米纯系选育新技术研究

以氟乐灵和炔苯酰草胺作为一种新的诱导剂,以不同遗传背景的玉米自交系及杂交种为试材,通过不同试剂、不同浓度、不同时期处理,进行化学诱导玉米孤雌生殖研究。结果表明,80μmol/L为氟乐灵和炔苯酰草胺的最佳诱导浓度,结实株率分别达到24.03%和36.36%;最佳处理时期在雌穗吐丝后第5天。杂交种的诱导效果普遍好于自交系及不同世代的材料,糯玉米好于普通玉米,Lancaster群好于Reid群。     

药剂诱导玉米孤雌生殖

试验用9种诱导剂配方处理了15份遗传背景不同的材料,研究了影响诱导玉米孤雌生殖诱导率的因素,其中包括材料、诱导剂种类和浓度、处理时期和方法。试验结果表明,药剂处理能提高玉米孤雌生殖结实率,并从所选试材中筛选出最佳诱导剂配方为0.1%COL 0.1%DMSO,孤雌生殖诱导率可达0.237%;组合药剂的诱导效果优于单一药剂的诱导效果;最佳处理时期和方法是吐丝前向苞叶内注射诱导剂;最佳诱导孤雌生殖材料为糯玉米杂交种,其次为普通玉米群体材料。     

化学药剂诱导玉米孤雌生殖选育自交系初报

用DMSO、PEG、6-BA等3种药剂7种诱导剂配方,处理140穗玉米自选系．收获78粒。初步断定获得纯自交系48个。筛选出最佳诱导剂配方DMSO2％＋PEG500mg／L＋6-BA500mg／L;单一药剂以6-BA500mg／L的诱导效果最好。     

诱导玉米孤雌生殖选育自交系研究初报

诱导玉米孤雌生殖,是一项快速选育玉米优良自交系的高新技术。它具有选育自交系年限短、效率高、用地少、简便省事的优点。经过几年研究探索,我们已经筛选出效率较高的诱导物质,确定了诱导物质的最佳使用时期与使用浓度,筛选出一批玉米孤雌生殖后代材料和自交系,测交筛选出较当地对照品种户单4号高产、早熟的玉米新组合N13－4×N3－9－4等。但诱导玉米孤雌生殖选育优良自交系,还存在诱导率低而不稳的问题,需要进一步研究提高。     

Col和DMSO诱导矮败小麦孤雌生殖的研究

在设置的隔离区内，种植矮败小麦轮回选择群体，以不育株为供试亲本，用秋水仙素（Ｃｏｌ）和二甲基亚砜（ＤＭＳＯ）诱导孤雌生殖。试验结果表明，Ｃｏｌ和ＤＭＳＯ均具有诱导不育株孤雌生殖的作用，并且二者之间存在极显著的互作效应。同一药剂不同的诱导方法，其诱导效果存在差异．小穗剪颖后再将药液滴入颖花内的孤雌生殖结实率较高；用药处理时间和用药后穗子套袋与否对孤雌生殖结实率影响不显著。经鉴定，孤雌生殖纯系在纯度和遗传稳定性方面均接近于对照品种（丰抗８号）．本文从遗传理论和育种实践的角度，对药物诱导矮败小麦孤雌生殖的可行性及在小麦育种中的应用价值进行了讨论。     

除草剂诱导玉米孤雌生殖新技术的应用及问题讨论

用除草剂诱导玉米孤雌生殖作为玉米自交系选育的新方法已开始在育种上应用。根据多年研究和应用实践,对该技术的诱导效果、诱导机理、技术特点、倍性和伪株问题、该技术的特殊用途及发展潜力进行分析和讨论。     

魔芋高效再生体系的建立与优化

研究不同激素及浓度配比对魔芋愈伤组织、不定芽和根诱导的影响。结果表明,诱导愈伤组织的最佳激素组合为ＭＳ＋６－ＢＡ０.5 ｍｇ／Ｌ＋ＮＡＡ ０．５ ｍｇ／Ｌ,其诱导率为８２％;诱导不定芽分化的最佳配方为ＭＳ＋６－ＢＡ １．５ ｍｇ／Ｌ＋ＮＡＡ ０．５ ｍｇ／Ｌ,其分化率为４９０％;诱导生根的最佳激素组合配方为ＭＳ＋ＮＡＡ ０．５ ｍｇ／Ｌ＋６－ＢＡ １．０ ｍｇ／Ｌ,其生根率为９０％。     

Col和DMSO诱导矮败小麦孤雌生殖的研究

在设置的隔离区内，种植矮败小麦回选择群体，以不育株为供试亲本，用秋水仙素（Ｃｏｌ）和二甲基亚砚（ＤＭＳＯ）诱导孤雌生殖。试验结果表明，Ｃｏｌ和ＤＭＳＯ均具有诱导不育株孤雌生殖的作用，并且二者之间存在极显著的互作效应。同一药材不同的诱导方法，其诱导效果存在差异，小穗剪颖后再将药液滴入颖花内的孤雌生殖结实率较高；用药处理时间和药处理时间和用药后了套袋与否对孤雌生殖结实率影响不显著。经鉴定，孤雌生殖纯系     

玉米孤雌生殖诱导系及标记基因的观察

本文观察比较了玉米孤雌生殖诱导系的单倍体诱导频率、开花习性和农艺性状表现,以及几个标记性状的主要特点。结果表明:WS14和Stock6两个诱导系均能诱导产生玉米孤雌生殖单倍体,诱导频率分别为3.06%和1.61%,分别比对照系提高35倍和18倍。但两个诱导系均存在植株矮小、生育期较短、生产能力较低,尤其是难以散粉等缺点,作为诱导系直接应用于玉米育种尚有较大困难。在观察的几个标记性状中,以显性基因Rnj和Pu联合应用效果最好,可有效地识别玉米孤雌生殖单倍体,单独应用则存在一定限制。隐性基因gl₁识别可靠性较好,但需转育到育种材料中才能利用,而隐性基因lg₁则由于可给育成自交系带来明显缺点性状而难以利用。     

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).