香草兰花粉保存与种间杂交育种初步研究

利用大花香草兰、帝皇香草兰与墨西哥香草兰进行种间杂交育种,以期改变目前生产上香草兰品种单一的局面。对香草兰花粉的保存方法进行研究,同时以人工授粉进行3个种间的正反交,统计杂交组合的结实率并观测杂交果荚的生长发育。结果表明,香草兰花粉适宜用花粉粒离体方式在4 ℃低温中保存50 d;6种香草兰杂交组合的平均结实率为78％,共得到31个的杂交果荚;6种香草兰杂交果荚的生长发育有一定差异,其形状与母本自交果荚类似;部分杂交果荚的长度和宽度与母本自交果荚有显著差异。香草兰杂交果荚内含有数量庞大的杂交种子,是潜在的香草兰育种新种质。     

甲霜灵在西瓜及土壤中的残留消解动态研究

采用高效液相色谱检测方法,研究甲霜灵在西瓜及土壤中2a的残留消解动态及最终残留。结果表明:甲霜灵在西瓜和土壤上的半衰期为4.10~4.30 d和8.61~9.55 d。甲霜灵灌根施药后,西瓜全果经过14 d,土壤经过28 d,消解率都达到85%以上。按最高推荐剂量500 g.a.i/hm2和1.5倍高剂量750 g.a.i/hm2使用3~4次,收获距末次施药间隔5、7、14 d,甲霜灵在西瓜全果、瓜肉和土壤中的最终残留量均低于中国食品中甲霜灵的最大残留限量标准0.2 mg/kg。所以甲霜灵在海南地区西瓜上按照推荐剂量300~500 g.a.i/hm2灌根2~3次,采摘间隔期7 d以上是安全的。     

不同疏果处理下香草兰果荚脱落及其内源激素含量变化研究

香草兰果荚发育中存在严重的果荚脱落现象,对香草兰果荚脱落情况及其內源激素含量变化进行探讨,以期解决目前生产上果荚脱落率高的问题。设疏果后保留1个、8~10个香草兰果荚以及未疏果共3种处理,从果荚发育至脱落的60 d内分期取材,采用酶联免疫法分别测定各处理果荚中生长素(IAA)、赤霉素(GA)、玉米素核苷(ZR)和脱落酸(ABA)的含量。结果表明:3种处理的果荚脱落率与保留果荚数目呈正相关;IAA和ZR的含量在前期较高,ABA的含量在中、后期较高,GA的含量一直维持在较低的水平;较高的IAA/ABA和(IAA+GA+ZR)/ABA比值有利于控制果荚脱落;疏果处理有利于坐果的激素平衡,而保留过多的果荚则不利于形成激素平衡。本研究可为解决生产中的香草兰落荚问题提供理论依据和技术方法。     

吡虫啉在海南豇豆及土壤中的消解动态研究

建立了豇豆、土壤中吡虫啉测定高效液相色谱法,并研究吡虫啉在海南豇豆和其种植土壤中的消解动态以及在豇豆中的最终残留。结果表明:方法回收率为78%~89%,在0.05~5μg/mL线性关系良好,相对标准偏差(RSD)7%,最低定量限0.01μg/mL,方法满足检测工作要求。吡虫啉在豇豆和土壤中的半衰期分别为2.9、5.1 d。以1.5倍推荐剂量一次喷施农药2.5 d后吡虫啉残留量小于0.5μg/g。吡虫啉在土壤中半衰期较短,属于易降解农药;分别以1.5、2倍推荐剂量3次施药,每次施药间隔2d,自然降解4、6d后残留量均低于0.5μg/g。     

吡虫啉在甘蔗茎和叶中残留动态研究

为了解甘蔗施用吡虫啉后在茎和叶中的残留变化,采用液相色谱法检测了甘蔗茎和叶的残留量。结果表明,在甘蔗种植后追肥时施吡虫啉1次,施药后50d,研究的两个甘蔗品种蔗茎中吡虫啉含量达到最高,60d含量低于0.04mg/kg;施用后20~30d甘蔗叶中最高,60d含量低于0.06 mg/kg,90d含量低于0.04mg/kg。     

甲哌(钅翁)打顶剂在棉花叶片和土壤中消解动态分析

通过盆栽试验,研究甲哌(钅翁)化学打顶剂在棉花叶片和土壤中的残留量及消解动态,以期为该药剂在棉花上的合理使用及制定其在棉花上的安全残留限量值提供依据。结果表明,甲哌(钅翁)在棉花叶片和土壤中的消解动态均符合一级降解动力学方程;在棉花叶片中的半衰期为13.90 d,在土壤中的半衰期为19.80 d;施药后60 d,在棉花叶片和土壤中的残留量分别为0.73 mg·kg^-1和0.41 mg·kg^-1。综上,甲哌(钅翁)棉花打顶剂用于化学打顶时,药后60 d在棉花叶片及土壤中的残留量较低,安全性较好。     

苯醚甲环唑在水稻和稻田中的残留

  为明确苯醚甲环唑在稻田系统的使用安全性,调查了我国3个不同水稻种植区域(湖南长沙、吉林长春和浙江杭州)苯醚甲环唑在稻田系统中的残留消解动态以及在糙米、稻壳、水稻茎秆和土壤中的最终残留量。按高剂量(112.5 g/hm2)施药1次后,苯醚甲环唑在不同种植区域水稻植株、稻田水和土壤中的半衰期分别为6.1~8.9 d,5.3~6.2 d和3.8~4.1 d。各试验点最终残留结果表明,施药后28 d采样时糙米中苯醚甲环唑的最终残留量均<0.01 mg/kg,水稻茎秆中含量最高,土壤中均未检出苯醚甲环唑(<0.01 mg/kg)。结合生产实际,按该试验设计的施药剂量、施药次数和采收间隔期,糙米、水稻茎秆和稻壳中苯醚甲环唑的残留量是安全的,但若是稻渔共作种植方式,则应尽量避免该农药的使用,以免对鱼类造成不利影响。     

小麦中嘧菌酯残留及膳食摄入风险评估

为对嘧菌酯在小麦生产上应用的安全性进行评价,采用田间试验,使用QuEChERS方法进行样品前处理,气相色谱法电子捕获检测器进行定量分析,对嘧菌酯在小麦中的残留动态及最终残留量进行了研究,并对小麦籽粒中嘧菌酯残留量进行了膳食摄入风险评估。结果表明,在0.01~1.0mg·kg~(-1)添加水平范围内,嘧菌酯在植株、籽粒空白添加的平均回收率为87.9%~108.4%,相对标准偏差为1.1%~6.2%,其最小检出量为5×10~(-12)g,植株、籽粒中的最低检测浓度均为0.01mg·kg~(-1)。该检测方法准确度、灵敏度高,重复性好,可满足嘧菌酯在小麦植株及籽粒中的残留分析要求。消解动态研究表明,嘧菌酯在小麦植株中的消解半衰期为3.3~4.3d。最终残留试验表明,20%嘧菌酯可湿性粉剂按施药剂量180、270g a.i.·hm~(-2),连续喷药2~3次,施药间隔7d,药后7、14、21d,嘧菌酯在小麦籽粒中的最终残留量均≤0.354mg·kg~(-1)。普通人群嘧菌酯的国家估算每日摄入量是2.43mg,占日允许摄入量的19.0%左右,因此,按本试验方式进行施药,不会对一般人群健康产生不可接受的风险。     

香蕉和土壤中吡唑醚菌酯的残留分析

建立吡唑醚菌酯在香蕉全蕉、蕉肉及土壤中的残留分析方法,测定吡唑醚菌酯在云南、海南两地香蕉及土壤中的残留动态及最终残留。结果表明：在0.01~0.1 mg/kg添加范围内,吡唑醚菌酯在香蕉果、肉、土中的平均回收率为82％~104％,变异系数为1.3％~3.6％;方法最小检出量为1×10-10 g,最低检出浓度为0.01 mg/kg。吡唑醚菌酯在云南和海南两地香蕉中的半衰期分别为17.2、16.7 d,在土壤中的半衰期分别为19.9、17.9 d。施药后35、42、49 d收获的香蕉中吡唑醚菌酯残留量均低于0.02 mg/kg。该方法准确度高,灵敏度高,线性良好。     

小麦和土壤中噻虫嗪残留及消解动态分析

为对噻虫嗪在小麦生产上应用的安全性进行评价,通过对小麦籽粒、植株和土壤进行前处理及在样品中添加噻虫嗪,建立其残留量定量检测分析方法;通过两年三地的残留试验,分析了小麦籽粒、植株和土壤中噻虫嗪的残留及消解动态,并对小麦籽粒中的残留量进行风险评估。结果表明,噻虫嗪在小麦籽粒、植株及土壤空白添加平均回收率为79.62%~94.70%,相对标准偏差为0.91%~6.56%,其最小检出量为5.0×10-8g,小麦籽粒、植株及土壤中的最低检测浓度均为0.01mg·kg-1。该检测方法重现性好,准确度、精密度高,可满足噻虫嗪在小麦及土壤中的残留分析要求。2011和2012年,河南、黑龙江和江苏三地噻虫嗪在小麦植株和土壤中的消解半衰期分别为0.85~2.24d和2.77~4.79d;通过不同施药次数、施药量及间隔采样检测,噻虫嗪在小麦籽粒中的最终残留量均≤0.038mg·kg-1,占日允许摄入量的15.04%左右(普通人群噻虫嗪的国家估算每日摄入量是0.25mg),因此按本试验方式进行施药,通常不会对一般人群健康产生不可接受的风险。     

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.