Natural Products: Repellency and Toxicity of Wild Tomato Leaf Extracts to the Two-Spotted Spider Mite,Tetranychus urticae Koch

The potential of using phytochemicals from leaves of wild tomato for controlling the two-spotted spider mite, Tetranychus urticae Koch, is explored in this study as a promising alternative to the use of synthetic pesticides. Wild tomato accessions of Lycopersicon hirsutum plants that are not consumed by humans were planted under greenhouse conditions for mass production of leaves. Crude extracts from leaves of three accessions of L. hirsutum, six accessions of L. hirsutum f. glabratum, and one accession each of L. pennellii and L. pimpinellifolium were prepared in chloroform, ethanol and hexane. Two spider mite bioassays, one a measure of antibiosis and the other a measure of repellency, were utilized to determine the acaricidal performance of the crude extracts. The bioassay for antibiosis was a 6-h no-choice test. The bioassay for repellency utilized a ring bioassay. Chloroform leaf extracts of L. hirsutum f. glabratum accessions (PI-251304, PI-134417, PI-134418, and PI-126449) exhibited greatest antibiotic activity on two-spotted spider mites; the hexane extracts exhibited greatest repellency. Extracts from PI-251304, PI-126449, PI-134417, and PI-134418 were especially lethal (chloroform) or repellent (hexane). We investigated differences in chemical composition of the crude leaf extracts that may explain the observed differences in mortality and repellency among the different accessions. Major chemical compounds (α -curcumene, α -zingiberene, trans-caryophyllene, 2-undecanone, and 2-tridecanone) known to have pesticidal efficacy were detected and quantified in the crude leaf extracts using a gas chromatograph (GC) equipped with a mass spectrometer (GC/MS). Lethality of extracts was mainly associated with the presence of high concentrations of 2-tridecanone; repellency of extracts was mainly associated with the presence of trans-caryophyllene. Leaf extracts of L. hirsutum f. glabratum accessions that contain significant quantities of 2-tridecanone and/or trans-caryophyllene could be useful for managing populations of spider mites, which could reduce reliance on synthetic pesticides.     

改良型AO法组合工艺中有机物的三维荧光分析

采用三维荧光(EEM)光谱技术,对上海竹园第二污水处理厂改良型AO法组合工艺运行过程中的各种溶解性有机物(DOM)进行分析,并对比研究传统好氧活性污泥法曝气池出水和A/O脱氮工艺硝化池出水DOM的EEM光谱的迁移变化特性.结果表明,各种DOM中主要的荧光物质有类蛋白质(荧光峰A和B)及类腐殖质(荧光峰C),经改良型AO法组合工艺处理后,荧光峰的强度降低了14％～60％,同时类蛋白质和腐殖质的结构也发生了变化;腐殖酸溯源表明DOM中的腐殖酸以微生物代谢产生的带有荧光基团的腐殖酸类为主.     

Natural Products: Seasonal Variation in Trichome Counts and Contents in Lycopersicum hirsutum f. glabratum

Abstract

Wild tomato leaves possess a pest-resistance mechanism in their glandular trichomes and the exudates they produce. Type IV and VI glandular trichomes on the leaves of five wild tomato accessions of Lycopersicum hirsutum f. glabratum (PI 126449, PI 134417, PI 134418, PI 251304, and LA 407) grown under greenhouse conditions were counted. Major chemical compounds from glandular leaf trichomes of the accessions tested were extracted, purified, and quantified at different periods during the growing seasons by gas chromatography (GC) and mass spectrometry (GC/MS). The toxicity of two methylketones (2-undecanone and 2-tridecanone), the major constituents of the accessions tested, to adults of the sweetpotato whitefly, Bemisia tabaci (Gennadius) and fourth instar larvae of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), was determined using no-choice bioassays. 2-undecanone caused 80% mortality of the fourth instar larvae of the CPB at the highest concentration tested (100 mg 2-undecanone mL^{? 1} of acetone) while 2-tridecanone caused 72% mortality of whiteflies at 20 mg 2-tridecanone mL^{? 1} of 65% ethanol. The concentration of 2-undecanone and 2-tridecanone on the leaves of each of the five accessions of L. hirsutum f. glabratum and the mass spectra of 2-undecanone and 2-tridecanone are presented. Overall, the concentration of 2-undecanone on the leaves was significantly higher than 2-tridecanone. Concentration of the two methylketones varied among accessions and sampling season. Plants produced the highest concentration of 2-undecanone during the month of August. On average, each plant of accession PI 251304 provided 354 g fresh leaves (averaging about 52,353 cm² exposed leaf surface area) and produced 32.5 and 8.7 mg of 2-undecanone and 2-tridecanone, respectively. L. hirsutum f. glabratum accessions may become a valuable source of natural products, which could minimize reliance on synthetic pesticides.     

水中一氯胺和二氯胺的紫外连续流动测定

本文研究了二氯胺与溴化钾的反应及其产物。采用微孔渗透膜分离－紫外分光测定系统,测定水溶液中的一氯胺与二氯胺。本法的线性范围为２×１０＾－５ｍｏｌ·ｌ＾－１－１×＾－２ｍｏｌ·ｌ＾－１,标准偏差在２×１０＾－４ｍｏｌ·ｌ＾－１时为４．３％。     

贵州喀斯特地区旅游资源的变异与可持续利用

喀斯特景观与民族文化是不可再生的旅游资源,其开发在促进喀斯特地区经济、文化发展的同时,也加剧了环境的损耗和地方特色的消失,旅游资源变异现象普遍发生。文中分析了资源变异的几种情况,并指出控制资源变异,实现可持续利用的途径     

运用三维荧光光谱解析高温厌氧产氢反应过程对温度变化的响应

为建立反应器运行状态的荧光光谱快速监测方法,应用三维荧光光谱表征了高温厌氧反应器的出水,采用平行因子分析方法分析后得到3种荧光组分——蛋白质、辅酶NADH和核黄素,并获得它们的激发发射光谱图及相对浓度.结果表明,当温度从50 ℃上升到60 ℃的过程中,3种荧光物质的相对浓度均呈现相应的变化,它们与反应器的运行参数呈现明显相关性.进一步研究表明,核黄素是高温厌氧产氢反应中的特有荧光物质,采用标准加入法和二阶校正方法可以测定其实际浓度,出水中核黄素浓度变化范围为0.04~0.13 mg·L^-1.该研究为厌氧产氢反应器的运行监控提供了理论基础.     

博斯腾湖夏季水下光场特征分析及影响因素探讨

2011年8月,在新疆博斯腾湖17个站点进行水样采集,同步对11个站点进行水下光场原位测定.结果发现,博斯腾湖夏季总颗粒物吸收系数光谱表现出明显的浮游植物吸收特征,而浮游植物光谱曲线有明显的硅藻吸收光谱特征.在光合有效辐射波段,有色可溶性有机物（CDOM）吸收系数与浮游植物吸收系数对总吸收的贡献相当,而非色素颗粒物对总吸收的贡献最低.水下光谱衰减系数的最小值出现在580nm左右的绿光波段,PAR漫射衰减系数平均值为0.53m-1,平均真光层深度约为9.69m,大于湖水平均深度.在博斯腾湖虽然纯水和CDOM在总吸收中占有很重要的部分,但主导漫射衰减的因子仍为颗粒物.通过本文研究,以期能为干旱地区湖泊环境保护和水质遥感监测提供数据和理论基础.     

不同地域的阳光光谱分布特性

目的研究阳光的光谱能量分布特性。方法对高原、西北沙漠、热带海洋等3个地域200~800 nm波段的阳光进行光谱测量,分析不同地区、不同天气状况、不同扫描速度下的阳光光谱能量分布特性。结果高原地区阳光光谱中的紫外-可见波段的辐照强度明显比西北沙漠和热带海洋地区高,多云时200~800 nm波段的辐射总量与晴天相比降低1/4,200~400 nm的紫外波段的辐射总量仅为晴天时的54%。光谱测量仪的扫描速度对光谱测定结果基本无影响。结论研究获得的阳光紫外截止点、340 nm处的辐照强度、不同波段的辐照量,可为实验室光源暴露试验中的光源选择、光谱能量控制提供参考。     

湖南郴县千里山花岗岩及其衍生岩脉云母矿物的红外光谱研究

湖南郴县千里山花岗岩及其衍生岩脉云母矿物系统的红外光谱分析结果表明:这些云母矿物分属于Li-Fe系列和Li-Al系列,前者所有红外光谱吸收峰波数均较后者相应的吸收峰值低;羟基伸缩振动与云母~(v1)Al的含量有关;(Al)Si-O-Si的对称伸缩振动与~(vl)Li~+含量关系密切;而Si-O弯曲振动或O-Me(金属)伸缩振动的频率变化则主要受~(vl)Fe~(2+)的含量制约。不同类型的云母有时其成分与红外光谱振动频率的关系有各自的规律,根据这一关系可以大致划分云母种属并粗略估计云母中某些主要组分的相对含量。结合云母产状的分析,两个系列出现于花岗岩蚀变的不同演化阶段,这对探讨岩体演化及矿化规律有一定的意义。     

Numerical evaluation of the effectiveness of NO2 and N2O5 generation during the NO ozonation process

Wet scrubbing combined with ozone oxidation has become a promising technology for simultaneous removal of SO₂ and NO_x in exhaust gas. In this paper, a new 20-species, 76-step detailed kinetic mechanism was proposed between O₃ and NO_x. The concentration of N₂O₅ was measured using an in-situ IR spectrometer. The numerical evaluation results kept good pace with both the public experiment results and our experiment results. Key reaction parameters for the generation of NO₂ and N₂O₅ during the NO ozonation process were investigated by a numerical simulation method. The effect of temperature on producing NO₂ was found to be negligible. To produce NO₂, the optimal residence time was 1.25 sec and the molar ratio of O₃/NO about 1. For the generation of N₂O₅, the residence time should be about 8 sec while the temperature of the exhaust gas should be strictly controlled and the molar ratio of O₃/NO about 1.75. This study provided detailed investigations on the reaction parameters of ozonation of NO_x by a numerical simulation method, and the results obtained should be helpful for the design and optimization of ozone oxidation combined with the wet flue gas desulfurization methods (WFGD) method for the removal of NO_x.