橡胶种子及萌发苗的抗氰呼吸

结果表明,橡胶种子各部位的抗氰呼吸速率不同,种子在发育、贮藏和萌发进程中抗氰呼吸的速率也不相同。总之,活力高的种子以及种子及苗的活跃生长部位或组织抗氰呼吸所占比率较高。     

橡胶种子萌发苗的抗氰呼吸

结果表明，橡胶种子各部位的抗氰呼吸速率不同，种子在发育、贮藏和萌发过程中抗氰呼吸的速率也不相同。总之，活力高的种子以及种子及苗的活跃生长或部位或组织抗氰呼吸所占比率提高。     

橡胶树抗氰呼吸的初步研究

橡胶树树发组织切片经氰化物处理后可以诱导出抗氰呼吸,在抗氰呼吸被诱导前,存在由切割组织所引起的创伤呼吸。为了避免切割组织所产生的创伤呼吸对抗氰呼吸测定的可能的干扰。我们对无机械损伤的幼树进行了整体下局部茎干组织的呼吸测定,气相色谱分析表明,在无机械损伤的情况下,不发生创伤呼吸而只存在氰化物所诱导的抗氰呼吸。氰化物所诱导的应澈乙烯和抗氰呼吸的诱导密切相关。抗氰呼吸抑制剂水杨径肟酸强烈地抑制组织切片的创伤呼吸,并在相当长时间内抑制陈化的组织的呼吸。可见,创伤呼吸和陈化的组织的呼吸都包含有抗氰呼吸的成分。氰化物 水杨羟肟酸则更强烈地抑制组织切片的呼吸。在组织切割至陈化的过程中,存在创伤乙烯和陈化组织所产生的乙烯两个峰。氰化物强烈地抑制创伤乙烯的形成,而促进陈化过程中所产生的乙烯;水杨羟肟酸完会抑制创伤乙烯的形成,而强烈地促进组织在陈化过程中所产生的乙烯。我们推断创伤乙烯和陈化过程中所产生的乙烯的形成机理可能是不同的。氰化物 水杨羟肟酸完全抑制上述两种乙烯的形成。     

6048多胞质雄性不育系的选育

以雄性不育细胞质(CMS)中S群的S、M、R与21A及C群的Rb、Es等多种细胞质为背景,采用回交转育的方式,完成了6048雄性不育自交系的选育,不育株率与单株不育率均达100%,不育性稳定。6048可作为在玉米雄性不育育种和生产应用的雄性不育细胞质资源,应用前景广阔。     

棉花雄性不育系的研究现状与利用前景

本文从四个方面对棉花雄性不育系的研究现状与利用前景进行综述：(1)棉花雄性不育系的研究进展情况；(2)棉花雄性不育系的形态特征及其与外界环境因素之间的关系；(3)棉花雄性不育系在棉花的杂交制种中的利用；(4)棉花雄性不育系在生产应用中应解决的几个问题及其应用前景：     

美国比马棉雄性不育突变体Ms_(12)的遗传

1976年在大田发现了一株雄性不育的美国比马棉植株。棉花雄性不育作为标志性状和在人工杂交中用雄性不育系作母本是很有用的。本研究的目的是测定基因控制的比马棉雄性不育性状的遗传和检测比马棉雄性不育基因与其它突变体基因之间的可能连系。比马棉雄性不育株和正常的雄性可育“比马S-5”植株之间进行杂交,产生了雄性不育和雄性可育的F_1 植株,其比例为1∶1。F_1 不育株与比马S-5杂交的BC_1 后代符合1不育∶1可育的比例。F_1 可育株与比马S-5杂交只产生可育的后代。这些资料证明雄性不育性状受一个显性基因控制。该性状定名为雄性不育12,基因符号为Ms_(12)。连锁测验证明Ms_(12)与23个棉属突变体基因之间没有任何关联。本文还讨论了Ms_(12)与其它遗传的雄性不育性之间的相互关系。     

高粱不同细胞质不育系的测交分析

高粱迈罗卡佛尔体系是杂交种种子生产所用雄性不育性的主要来源。除最初发现的迈罗(A_1)雄性不育性外,现已报导了另外的雄性不育细胞质(Schertz等,1982;Rao等,1984)。新诱导的雄性不育细胞质对避免可能与细胞质有关联的病害和     

甘兰型油菜细胞质雄性不育“三系”及其杂种一代花器官形态变异规律

利用甘兰型油菜(Brassica napus var.Oleifera)的雄性不育性,是杂交优势育种的主要途径之一。本研究旨在探索与育性有关的花器官形态解剖指标及其遗传变异规律,用以指导“三系”选育实践。初步阐明:(1)油菜细胞质雄性不育系与细胞核雄性不育系花药发育停止时期明显不同。(2)花瓣宽度、花药长度和♀/♂值等三个性状与育性恢复基因密切连锁,是判断细胞质雄性不育系及其测交后代育性变异的主要形态指标。(3)因此,根据细胞质雄性不育系测交F_1花器官形态的表现型,可以推测测交品种核基因的显隐性程度及其恢、保特性。     

雄性不育大豆研究概况

(一) 在大豆田间偶尔可以发现大豆雄性不育株,其中有的是部分雄性不育,在这种植株上结有5—6个少量的豆荚。在引种外地品种时和在某些杂交组合或辐射杂交后代中往往见到这种现象。Hadley和Starnes(1964)首先报导了由于染色体联会上的障碍所造成的雄性不育。他们还认为在许多情况下不育性与某些变态是相关的,如矮态、短柔毛的缺乏。通过部分雄性不育植株与可育植株进行杂交的实验,可以说明这种部分的雄性不育是受细胞核控制的。根据醋酸洋红等染色方法对花粉进行检查,发现在部分雄性不育中只有5—10％的花粉是有活力的。     

棉花雄性不育系的研究现状及展望

综述了棉花雄性不育系的研究进展情况,简述了棉花雄性不育系的形态特征及其与外界环境因素之间的关系、棉花雄性不育系在杂交制种中的利用,并对棉花雄性不育系的应用前景进行了展望。     

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).