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21.
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以大豆内源基因(Lectin)、筛选基因35S启动子(Cauliflower mosaic virus 5S,CaMV35S)、NOS终止子(Nopaline synthase,Nos)和外源基因(CP4 EPSPS)为检测对象,对大豆深加工产品的DNA提取方法、PCR扩增条件的退火温度、引物浓度进行探讨,得出不同DNA提取方法、退火温度、引物浓度对大豆加工产品PCR检测的影响,建立了大豆加工食品中转基因成分定性检测体系。检测结果表明,退火温度60℃、引物浓度0.4μM时所建立的定性PCR检测方法能有效检测出大豆加工产品中的转基因成分,而且方法简单、快速有效。 相似文献
23.
Luigi Pane Elisabetta Giacco Christian Corrà Giuliano Greco Gian Luigi Mariottini Franco Varisco Marco Faimali 《Journal of Soils and Sediments》2008,8(2):74-79
Background, Aim and Scope The toxicity of contaminated sediments should be evaluated considering the direct exposure of laboratory organisms to whole
sediments and the indirect exposure to elutriates or extracts (Tay et al. 1992, Byrne and Halloran 1999, Nendza 2002). The
alga Dunaliella tertiolecta is indicated for the use in toxicity bioassays because it is highly sensitive to several xenobiotics. Harpacticoid copepods
have been already used for toxicity testing and Tigriopus fulvus is a promising Mediterranean target-species in ecotoxicology (Todaro et al. 2001, Faraponova et al. 2003, Pane et al. 2005a).
In this study, the toxicity of sediments collected in harbour sites of the Northeastern Adriatic Sea was evaluated by growth
inhibition test with free living and alginate-immobilized Dunaliella tertiolecta and acute toxicity test with nauplii and adult Tigriopus fulvus with the aim of pointing out the importance to utilize model organisms from different trophic levels in sediment ecotoxicology.
Methodology Elutriates and whole sediments were tested on free living and immobilized (Pane et al. 1998) algal cells, and on laboratory
reared copepods. Free-living D. tertiolecta were exposed to diluted elutriates in a static, multi-well plate system. Naalginate immobilized D. tertiolecta were placed in polystyrene inserts fitted with polyester mesh bottoms and exposed to a thin layer (2 mm) of whole sediments
in multi-well plates (EPS 1992, Pane and Bertino 1999). Toxicity tests with copepods were carried out on Tigriopus fulvus nauplii (elutriates) and adults (whole sediments and elutriates). Same-aged nauplii useful for toxicity tests were obtained
by egg sac detaching and consequent hatching stimulation (Pane et al. 2006). Newborn nauplii (I–II stage) were exposed to
elutriates in multi-well plates provided with polystyrene inserts. Adult T. fulvus maintained in polystyrene inserts fitted with polyester mesh bottoms were placed in contact with a thin layer (2 mm) of whole
sediment placed on multi-well plate bottoms. All end-points were evaluated after 96 h.
Results In general, the effects increased with the increasing of elutriate concentration up to 50%; the stimulation or inhibition
of algal growth was statistically significant in comparison to the control. The inhibiting elutriates induced EC50 variations of algal growth ranging from 66.9% to 74.3%. The mortality of T. fulvus nauplii was always < 25% after treatment with 100% elutriates and < 10% after treatment with 50% dilution; no effect was
shown up with 25% dilution; therefore LC50 was not calculable. The effect of elutriates was negligible on adult copepods and LC50 values were never calculable; percent mortality always resulted in < 10% after treatment with whole sediments.
Discussion Both experimental systems gave substantially similar results after exposition to whole sediments and elutriates. During the
experiment with algal cells, the immobilization in Na-alginate and the employment of inserts which allowed the contact of
organisms with sediments and their easy counting were particularly useful. Likewise, the employment of inserts of adequate
mesh size in the tests with copepods allowed the contact of organisms with the sediment and made organism handling and counting
easy, as well as the evaluation of mortality. The methodology here described and the utilization of the proposed test-species
could have an importance also considering that the current trend in ecotoxicological research is towards finding the most
appropriate organism for specific areas of concern by using indigenous species (Mariani et al. 2006) and towards the major
significance of chronic and reproductive end-points.
Conclusions Based on the above results, it can be stated that the bioassay with Dunaliella tertiolecta could be a good estimation tool for the ecotoxicological assessment of marine sediments. The immobilization of algae in Na-alginate
was seen to be useful to evaluate the toxicity of whole sediments; the employment of polystyrene inserts allowed an improvement
of the procedures. T. fulvus nauplii and adults, as other harpacticoids such as Tigriopus japonicus (Yoon et al. 2006), satisfy the basic criteria for the employment of a standard species in marine bioassays. To date only
pelagic Acartia tonsa are utilized in the standardized procedure to evaluate the risk assessment of chemicals or wastewaters (ISO 1999). As, on
the contrary, the exposure of copepods to solid-phase contaminants it is not yet standardized, the employment of polystyrene
inserts improved the procedures for T. fulvus too. So, the rapidity and the possibility to solve practical problems could be the main attractive features of this technique
(Pane et al. 2005a) when applied to whole sediments.
Recommendations and Perspectives The methodology here developed being also applicable to long term and reproduction tests should be recommended because it
provides relevant information in comparison with other frequently applied, standardized biotests with crustaceans (ISO 1999).
The procedure has been shown to be easily applicable to selected marine organisms.
ESS-Submission Editor: Prof. Dr. Henner Hollert (henner.hollert@bio5.rwth-aachen.de) 相似文献
24.
农作物品质受农作物遗传发育特征和环境因素的双重影响。在相似的遗传背景条件下,CO2浓度持续升高影响农作物中碳水化合物合成、有益和有害元素吸收的权重逐渐加大,从而引发所谓的“隐形饥饿”和农产品卫生品质下降。本文在回顾国内外有关CO2浓度升高影响农作物中碳水化和物合成、有益和有害成分吸收研究的基础上,结合本团队近年的研究结果,提出:随着产地环境污染由局部向整体扩延,CO2浓度持续升高对农作物卫生品质的潜在影响不断加剧,包括增加或减少农作物对有毒有害物质的吸收;强化农作物对土壤中有益或有害物质的非均衡吸收等。本文还对比了目前国内外CO2浓度升高对农作物品质影响研究的常用手段与方法,并对相关研究结果的差异进行了分析,着重指出这一研究方向今后工作的重点。 相似文献
25.
小麦黑胚病菌及其分离方法比较 总被引:2,自引:0,他引:2
河南省小麦黑胚菌主要是交链孢菌[包括细交链孢菌(Alternaria tenuis)与极细交链孢菌(A.tenuissima)]和麦类根腐德氏霉菌(Drechslera sorokimiana)。检验小麦黑胚病菌以组织分离法最为准确,以清水培养法较为简捷。 相似文献
26.
Honeydew produced by aphids is a well-studied food source for mutualistic ants. Although considerable amounts drop onto the soil surface there are hardly any studies dealing with the potential effects of this additional C source for soil organisms, particularly those living at the soil surface. We studied this question by simulating honeydew and investigating plots under Populus canescens formerly infested with aphids on two ruderal sites differing in soil organic matter content and vegetation cover. The simulated honeydew input increased microbial biomass with some delay in week 10. Both natural and simulated honeydew raised the activity densities of an epigeic Collembola taxon, the Bourletiellidae, but not of the dominant Hemisotoma thermophila. The honeydew effect varied over time and with the site, and was more pronounced at the nutrient-poor site for Collembola, but not for microbial biomass. Ant consumption reduced the amount of honeydew reaching the soil surface by 50%. The activity density of H. thermophila was negatively related to ants and spiders, hinting at a top-down control. Honeydew clearly acts as a bottom-up force for soil organisms, which is however only part of the complex network connecting the food webs of primary producers and decomposers. 相似文献
27.
28.
南海涛 《林业机械与木工设备》2012,(12):16-18
概述了近年来内蒙古大兴安岭林区外来有害生物的危害及分布情况,分析了该林区发展现状和面临外来有害生物入侵带来的问题和挑战,提出建立外来有害生物基因库,加强植物检疫宣传,科学调种、引种,加强公共防范意识,开展外来有害生物长效监控机制等5个方面工作来防御和治理林区外来生物入侵,为大兴安岭林区外来有害生物的预防和防治提供理论依据。 相似文献
29.
30.
松材线虫病的发生原因、危害症状及防治策略 总被引:1,自引:0,他引:1
松材线虫病能够引起大面积松树出现枯死现象,对松树林产生毁灭性伤害,属于世界性病害。为了有效促进我国林业发展,需要对松材线虫病加强防治。而目前我国在防治松材线虫病过程中难度相对较大,防治技术也比较滞后,资金不足等问题导致难以高效控制松材线虫病。基于此,深入探究松材线虫病的发生原因、危害症状,并提出了有效的防治策略。 相似文献