七种药剂对两种花生叶螨的室内毒力和盆栽药效测定

为明确7种常用杀螨剂对花生上二斑叶螨和朱砂叶螨的毒力差异和防治效果,为不同优势种群的防治提供高效药剂,采用浸虫法测定了7种杀螨剂对两种叶螨雌成螨和卵的毒力。毒力测定结果表明,螺虫乙酯对二斑叶螨成螨的毒力最高LC₅₀为1.213mg/L;哒螨灵、联苯肼酯、阿维菌素的毒力次之。阿维菌素对朱砂叶螨成螨的毒力最高LC₅₀为0.044mg/L;螺虫乙酯、哒螨灵、虫螨腈、联苯肼酯的毒力也较高;螺螨酯对两种成螨的毒力均最低。螺虫乙酯对二斑叶螨和朱砂叶螨卵的毒力均最高,LC₅₀分别为0.037mg/L、0.005mg/L。阿维菌素对二斑叶螨和朱砂叶螨成螨的毒力倍数差异最大,达247.8倍;其次是螺虫乙酯、虫螨腈毒力倍数为24.8倍和16.1倍;螺螨酯和阿维菌素对两种叶螨卵的毒力差异较大,分别达12.1倍和11.8倍。在盆栽花生上,43%联苯肼酯悬浮剂、22.4%螺虫乙酯悬浮剂、110g/L乙螨唑悬浮剂4000倍处理,对二斑叶螨的防效好,药后21d达83.75%～97.75%,显著高于其他药剂;7种药剂的4000倍液处理均对朱砂叶螨有很好的防效,药后21d达97.63%～100%。综上所述,除螺螨酯以外,6种供试药剂对朱砂叶螨成螨和卵的毒力均明显大于二斑叶螨,其中阿维菌素对两种成螨毒力差异最大。43%联苯肼酯悬浮剂4000倍液可有效同时防治两种叶螨,并有较好的速效性和持效性;其他6种药剂目前都是防治朱砂叶螨的高效药剂。本研究为防治叶螨合理用药提供了依据,对指导花生田叶螨的科学防治具有重要意义。     

皮氏叶螨生物学特性观察及5种药剂毒力测定

观察了6个温度条件及9种寄主植物对皮氏叶螨发育及繁殖的影响,并进行了5种药剂对此螨的毒力测定。结果表明:24~32℃为皮氏叶螨发育、存活和产卵的最适合温度,番木瓜为皮氏叶螨的最适宜寄主,其次为香蕉和番荔枝。香蕉品种间比较,巴西蕉和贡蕉分别为皮氏叶螨的最适和最不适宜的芭蕉属寄主。5种农药对皮氏叶螨雌成螨的毒力大小顺序为阿维菌素>阿维·氯>哒螨灵>果好迈>辛硫磷,其LC50分别为0.0586,0.4415,34.6817,35.0268和96.1017μg/mL。     

6个坚尼草品种比较试验报告

采用玻片浸渍法,进行了8种杀虫剂对海南白沙及东方两地的橡胶六点始叶螨(Eotetranychus sexmaculatus Riley.)♀成螨的室内毒力测定。结果表明：1.8% 阿维菌素对白沙及东方两地的♀成螨毒力均最高,LC50值分别为0.068 9、0.075 1 mg/L;其次为10% 溴虫腈和2.5% 高效氯氟氰菊酯,LC50值分别为15.481 6 、10.153 2 mg/L和431.895 2、350.068 2 mg/L,8种药剂对该螨雌成螨的毒力大小顺序均为阿维菌素、溴虫腈、高效氯氟氰菊酯、毒死蜱、哒螨灵、甲氰菊酯、三唑锡与克螨特。与敏感种群相比,白沙、东方两地六点始叶螨对克螨特、毒死蜱、甲氰菊酯、哒螨灵与三唑锡均已产生较高抗药性。     

杀虫剂对小菜蛾幼虫的毒力研究

采用浸叶法测定10种杀虫剂对海南省海口、三亚、儋州小菜蛾田间种群的毒力。结果表明：10种药剂对海口地区小菜蛾3龄幼虫的毒力LC50大小顺序为：Bt＞氟啶脲＞多杀菌素＞茚虫威＞虫螨腈＞阿维菌素＞丁醚脲＞虫酰肼＞杀螟丹＞高效氯氰菊酯;三亚地区小菜蛾3龄幼虫的毒力LC50大小顺序为：Bt＞多杀菌素＞氟啶脲＞茚虫威＞虫螨腈＞阿维菌素＞虫酰肼＞丁醚脲＞杀螟丹＞高效氯氰菊酯;儋州地区小菜蛾3龄幼虫的毒力LC50大小顺序为：Bt＞多杀菌素＞茚虫威＞氟啶脲＞虫螨腈＞阿维菌素＞丁醚脲＞虫酰肼＞杀螟丹＞高效氯氰菊酯。3个地区     

2 %阿维·绿僵菌素悬浮剂对朱砂叶螨的生物活性

为了解2 %阿维·绿僵菌素悬浮剂对朱砂叶螨的生物活性,采用盆栽幼苗喷雾法、盆栽幼苗喷雾法、保湿叶碟喷雾法研究了2 %阿维·绿僵菌素悬浮剂对不同生长阶段朱砂叶螨的生物活性,并采用茎内吸法、涂药法研究了2 %阿维·绿僵菌素悬浮剂的内吸性和渗透性,探讨了温度对其杀螨活性的影响。结果表明： 2 %阿维·绿僵菌素悬浮剂对成螨的活性(LC50：1.247 44 mg/L)优于唑螨酯(LC50：2.189 50 mg/L)和炔螨特(LC50：12.515 49 mg/L),对若螨的活性(LC50：0.362 31 mg/L)低于阿维菌素(LC50：0.279 71 mg/L),其杀卵活性(EC50：3.563 50 mg/L)优于哒螨灵(LC50：5.561 61 mg/L)但低于噻螨酮(LC50：0.274 23 mg/L);2 %阿维·绿僵菌素悬浮剂对不同生长阶段的朱砂叶螨均具有较高的活性,其内吸性、渗透性均较强,在一定的温度范围内,温度越高,杀螨活性越高。本研究结果为2 %阿维·绿僵菌素悬浮剂的田间应用提供了理论依据。     

离心管药膜法测试12种杀虫剂对香蕉花蓟马的毒力

室内采用离心管药膜法,选用12种杀虫剂原药对香蕉花蓟马若、成虫进行了毒力测定。结果显示,供试药剂对香蕉花蓟马二龄若虫的毒力(LC50)大小顺序为:甲维盐(1.63 mg/L)毒死蜱(2.18 mg/L)阿维菌素(5.11 mg/L)啶虫脒(5.86 mg/L)高效氯氰菊酯(5.90 mg/L)吡虫啉(6.59 mg/L)噻虫嗪(6.72 mg/L)噻虫胺(11.49 mg/L)杀虫单(13.25 mg/L)功夫菊酯(14.56 mg/L)噻嗪酮(20.47 mg/L)吡蚜酮(55.26 mg/L);对成虫的毒力(LC50)大小顺序为:甲维盐(2.82 mg/L)毒死蜱(4.46 mg/L)啶虫脒(6.41 mg/L)吡虫啉(6.62 mg/L)阿维菌素(6.83 mg/L)噻虫嗪(7.43 mg/L)高效氯氰菊酯(9.94 mg/L)噻虫胺(15.49 mg/L)功夫菊酯(15.87 mg/L)杀虫单(17.59 mg/L)噻嗪酮(30.26 mg/L)吡蚜酮(55.47 mg/L);供试药剂对成虫的LC50值不同程度大于若虫,表明药剂对香蕉花蓟马若虫的毒力高于成虫。     

锡兰肉桂的杀螨活性及有效成分

室内测定锡兰肉桂提取物对几种害螨的杀螨活性及其作用方式,并在活性跟踪的基础上,通过萃取、柱层析、核磁共振和质谱等方法对其有效成分进行分离及鉴定。结果表明,锡兰肉桂不同部位乙醇提取物均有一定的杀螨活性,其中叶和树皮的提取物活性最高。叶乙醇提取物对朱砂叶螨、皮氏叶螨、比哈小爪螨均有毒杀作用,其24h的LC50值分别为0.885、0.641、1.308g/L;对皮氏叶螨和朱砂叶螨还具有一定的杀卵作用,LC50分别为0.604、1.167g/L。从叶提取物中分离鉴定出活性成分丁香酚和松油烯-4-醇。丁香酚对皮氏叶螨表现出较高的毒杀活性,24h的LC50值为0.243g/L。而松油烯-4-醇则对皮氏叶螨的毒杀作用低于丁香酚,24h的LC50值为0.639g/L。分析认为,丁香酚可能为锡兰肉桂叶中主要的杀螨活性成分之一。     

大叶丁香丙酮提取物对皮氏叶螨的毒力及代谢酶活性的影响

采用叶片浸渍法和分光光度法研究了大叶丁香(Eugenia caryophyllata Thunb)丙酮提取物对皮氏叶螨(Tetranychus piercei McGrvgor)的毒力及其代谢酶活性的影响。试验结果表明:大叶丁香丙酮提取物对皮氏叶螨具有良好的毒杀作用,处理后72 h LC50值为4.31 mg/mLL;其13.33 mg/mL对皮氏叶螨的48 h和72 h校正死亡率分别为81.82％和95.35％,其6.67 mg/mL对皮氏叶螨的72 h校正死亡率为75.58％;大叶丁香丙酮提取物在5.0、4.0、3.0、2.0、1.0 μg/mL的质量浓度下,对皮氏叶螨酯酶、羧酸酯酶、碱性磷酸酯酶的活性均有抑制作用,作用大小均随处理浓度的增加而增强,但大叶丁香丙酮提取物对酸性磷酸酯酶则有一定程度的激活作用。      

假蒟提取物对皮氏叶螨的生物活性测定

通过索氏抽提和乙醇浸提法提取假蒟(Rper.saormentosum Roxb.)杀虫活性成分,即获得乙醇浸提物、乙醇索氏提取物和石油醚索氏提取物,研究其对皮氏叶螨(Tetranychus pieroei McGregor)各龄虫的触杀及对成螨驱避、产卵抑制等方面的生物活性.结果表明:乙醇浸提物和石油醚索氏提取物对皮氏叶螨卵的毒杀效果均较好,用20mg/g的浓度处理后,杀卵效果均在95%以上:对若螨的生物活性以乙醇索氏提取物最好,当浓度为15mg/g时,校正死亡率达95.19%,明显强于石油醚索氏提取物;乙醇浸提物、乙醇索氏提取物和石油醚索氏提取物对成螨的LC50分别为3.2141,6.093 1,3.518 8 mg/g,LC95分别为8.5750,18.700 7,9.311 4 mg/g;用质量分数0.4%乙醇浸提物和石油醚索氏提取液处理的皮氏叶螨成螨寿命明显短于乙醇索氏提取物和对照,产卵抑制指数以石油醚索氏提取物最高,为0.1465,乙醇索氏提取物最低,为0.0825;3种提取物对皮氏叶螨均有良好的驱避作用.     

防治水稻白背飞虱高毒农药替代药剂的室内筛选及对吡虫啉的抗性风险评估

 为筛选高毒农药的替代药剂,采用稻茎浸渍法测定了7类共21种杀虫剂对2006年和2007年采自南京市江浦地区的白背飞虱种群3龄若虫的毒力。结果表明,噻虫嗪、吡虫啉、噻嗪酮对白背飞虱3龄若虫的毒力最高(LC50=004~026 mg/L);烯啶虫胺、丁烯氟虫腈、吡蚜酮、啶虫咪、氯噻啉、毒死蜱、氟虫腈等也有较高的毒力(LC50＜4.50 mg/L）;异丙威、敌敌畏虽然触杀毒力稍低(LC50＞19.85 mg/L),但两者在生产上仍广泛应用,所以把以上12种药剂作为田间药效试验的推荐品种;同时还比较了该地区白背飞虱种群对供试药剂敏感性的年度间差异,其中对毒死蜱、异丙威、丁硫克百威、速灭威这4种药剂的敏感性下降了66.7%~71.4%。对2006年南京江浦种群用吡虫啉连续筛选15代的结果表明,1~15代抗性上升433倍,抗性现实遗传力为0.2295,存在抗性风险。另外,还讨论了白背飞虱的综合防治。     

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).