阿维菌素类药物在动物性食品中的残留检测研究概况

为了对动物性食品中阿维菌素类残留研究有更深入、全面的了解,并为我国开展阿维菌素类残留检测提供参考,文章综述了阿维菌素类药物(包括阿维菌素、伊维菌素、多拉菌素、依立菌素和莫西菌素)在动物性食品中的单残留和多残留检测方法,包括薄层色谱法、酶联免疫法、高效液相色谱法、液质联用法和液相色谱?质谱?质谱联用法。     

进口饲料中牛源性与转基因成分的检测

本文介绍了进口饲料中牛源性与转基因成分的PCR检测方法。该方法用异硫氰酸胍提取进口饲料样品DNA,以牛特异性引物扩增模板DNA,扩增产物为271bp,PCR产物经限制性酶切片段分析,与预期设想一致;方法灵敏度实验结果显示,饲料样品中含有0.1%的牛源性成分时仍能检出。同时,根据转基因农作物最常使用的外源基因设计引物,在进口饲料中检测出35S启动子和NOS中止子等转基因成分,具有快速、简便、准确等特点。     

浅析动物源性食品安全隐患及解决办法

随着我国经济的持续发展和人民生活水平的不断提高,人们对动物源性食品的需求产生了由量到质的转变,动物源性食品安全问题也逐渐显露,对公共卫生安全和人类的健康已造成严重的威胁,引起了各方面的高度重视。文章针对目前动物源性食品安全现状,对其存在的问题及带来的危害提出相应的解决办法,以保证动物产品的健康使用,促进畜牧业的迅速发展。     

湖州不同林型建群种生物量格局的研究

对湖州林区不同林型建群种生物量格局进行了研究分析 .湖州主要森林类型生物量的平均值变动于 8.2 5～ 1 0 0 .85 t/hm2 之间 ,单因素方差分析表明不同林型林木总生物量差异极显著 ,其中阔叶林最高为 1 0 0 .85 t/hm2 ,灌木林最低为 8.2 5 t/hm2 .多重比较 ( LSD)分析了不同林型林木两两之间生物量的差异性 ,其显著性差异程度因参比林种不同而异 .林木生物量与环境因子相关 ,经逐步回归统计分析筛选出影响不同林木生物量的主导生态因子 ,其回归性达到显著或极显著水平     

Dinitrogen fixation activity of Azorhizobium caulinodans in the rice (Oryza sativa L.) rhizosphere assessed by nitrogen balance and nitrogen-15 dilution methods

 Azorhizobium caulinodans was directly inoculated onto rice plants in three short-term pot trials. Addition of increasing amounts of sucrose (23, 46, 92 kg ha^–1) did not influence the N economy of the A. caulinodans-rice association during the early vegetative growth stage. A. caulinodans inoculation alone and in combination with the highest amount of sucrose had a significantly positive effect on the N balance, with small but significant N gains in the system. Application of 60 kg urea-N ha^–1 had a negative impact on the N economy of the inoculated treatments. N losses increased and the amount of atmospheric N₂ fixed and incorporated decreased significantly as compared to the amounts under the 20 kg urea-N ha^–1 regime. However, N losses were low – a maximum of 8% – at the early vegetative growth stage under the conditions of the experiments. C limitation does not seem to be a limiting factor for the incorporation of fixed N₂ in this bacteria-plant association. Biological N₂ fixation caused by A. caulinodans inoculation was responsible for 14% of the plant N at the vegetative growth stage and under low N conditions. Received: 30 January 2000     

Quantitative evaluation of elbe river-derived organic marker compounds in sediment samples from the german bight

Background, Goal and Scope  A large share of anthropogenic contamination of the coastal zone is a result of riverine contributions. Accordingly, the pollution of North Sea estuaries and coastal areas by organic xenobiotics is dominantly characterized by land-derived contamination. In a previous study, we identified a high number of organic contaminants in sediments of the German Bight emitted by industrial and municipal sources, primarily as a result of riverine contributions. Furthermore, a group of contaminants was identified representing Elbe-specific marker compounds. However, quantitative analyses are more adequate to describe the source specificity via the spatial distribution as compared to qualitative analyses. Hence, in the present investigation, the determination of various anthropogenic contaminants has been performed in order to evaluate the proposed Elbe-specific marker compounds. Methods  Numerous anthropogenic contaminants were quantified in seven surface sediment samples from the German Bight by means of gas chromatographic — mass spectrometric analyses. The analytical procedure includes extraction, reI moval of sulphur, fractionation, concentration and addition of internal standard. Results and Discussion  Two groups of Elbe-derived contaminants were differentiated. Substances of the first group appear only at sampling locations directly influenced by the Elbe river and include hexachlorobutadiene and alkylsulfonic acid phenyl esters. The second group consists of compounds, which occur additionally in minor concentrations at sites situated at a greater distance from the coastal area, which are therefore only influenced to a minor-degree by the Elbe river. However, their spatial and quantitative distribution characterizes them clearly as Elbe river-derived components. Compounds of the second group are tetra- to hexachlorinated benzenes, mono- and disubstituted chloronaphthalenes, tetrabutyltin, 4,4’-dichlorodiphenylsulfide and DDT related compounds In order to discern the discussed Elbe marker compounds from non-marker substances, several nonspecific contaminants were analyzed additionally. These contaminants include galaxolide, tonalide, tri-n-butylphosphate, 2,4,4-trimethylpentane-l,3-dioldi-iso-butyrate and 2,2,4,4,6,8,8-heptamethylnonane. No significant accumulation of these compounds was observed at sampling locations mainly influenced by either the Elbe river, or the Ems and Weser rivers. Conclusions  For the evaluation of the proposed Elbe marker compounds, the quantitative and spatial distribution was investigated and successfully discussed as the most important criterion to define their source specificity. Generally, these results illustrate how quantitative data on source-specific organic contaminants and the corresponding spatial distribution can be used to trace individual riverine contributions to the pollution of coastal areas. This approach might be especially useful to differentiate the contribution of several rivers discharging close together into the marine environment. Fingerprinting, the individual riverine contribution additionally allows one to quantify the individual, river-derived contamination. Subsequently, the level of coastal zone contaminations can be reduced more effectively. Further comprehensive analyses on numerous coastal and estuarine areas have to be done to support this approach.     

Resistance inVicia faba toOrobanche crenata: True resistance versus hidden susceptibility

Summary Orobanche attack on twelve broad bean cultivars was measured in connection with vegetative growth by means of two pot tests with different innoculum densities. Orobanche attack appeared to be related to the growth vigour of the host. The higher the root and shoot biomass of a cultivar, the higher the number and the more advanced the development of the tubercles was, independent of innoculum density. Therefore, in spite of the observed variation for Orobanche attack, the tested cultivars were considered to have the same level of susceptibility, however with exception of BPL 2210. This cultivar showed a lower attack than was expected of its growth vigour.Hollandseweg 2, 6706 KP Wageningen, the Netherlands.     

Testcross performance and diversity analysis of white maize lines derived from backcrosses containing exotic germplasm

Introgression from exotic maize (Zea mays L.) into adapted breeding pools can broaden and diversify the genetic base of adapted germplasm. The first objective of this study was to determine the agronomic performance of white maize lines derived from adapted × exotic backcrosses in tropical environments. Six exotic white maize inbred lines were crossed to an adapted white line (1368) and the F₁s were backcrossed to 1368. Forty-one BC₁F₄ lines derived from these backcrosses and the recurrent parent were crossed with a common inbred tester (9071) and the progeny were evaluated at eight environments in Nigeria. The testcrosses × environment interaction mean square was not significant for all agronomic traits. The BC-derived lines containing exotic germplasm contributed significantly to the variation in testcross mean grain yields and other agronomic traits. Among the 41 testcrosses, only 5 yielded significantly less than 1368 × 9071, with the 7 best testcrosses producing between 304 and 867 kg ha⁻¹ more grain than 1368 × 9071. The second objective of this study was to assess the genetic divergence of the BC-derived white lines from their adapted recurrent parent. Thirty-nine BC-derived white lines along with 1368 and 9071 were genotyped with ten AFLP primer pairs that generated 506 polymorphic fragments. The average allelic diversity of the lines was 31 ± 0.07. The genetic distance (GD) estimates of each BC-derived line from 1368 varied from 0.76 to 0.84, with a mean of 0.80 ± 0.003. The average GD for all pairs of the BC-derived lines was 0.63 ± 0.005, varying from 0.31 to 0.89. The observed significant amount of variation among the BC-derived white lines suggests that they can contribute new alleles for expanding the genetic base of tropical maize and for developing high-yielding hybrids.     

白花草木樨半同胞家系的生物固氮性状评价

以不同的白花草木樨(Melilotus albus)半同胞家系为试验材料,分别种植于甘肃临泽和榆中,测定其根干重、根瘤数、根瘤重、叶全氮、叶全磷和生物固氮百分率,以此评价其生物固氮能力。结果表明,白花草木樨在两个地区表现出的各项固氮指标变异系数均大于15%,主成分分析后,可将半同胞家系划分为4组,组1白花草木樨家系的根干重、根瘤数、根瘤重、叶全氮、叶全磷和生物固氮百分率分别高出对照当地白花草木樨品种(RX-02)4%、26%、10%、17%、24%、11%,其中生物固氮百分率的最大值和最小值分别为58%和43%。本研究筛选出的优良生物固氮性状的后代家系,可为进一步选育生物固氮能力强的新品种奠定基础。     

Chelex-100快速提取动物源饲料DNA方法的建立

为防止疯牛病疫区反刍动物源性饲料传入我国,非常有必要对贸易往来中的肉骨粉品种来源进行鉴定。本文建立了一种利用Chelex—100快速提取动物源性饲料DNA的方法,用于反刍动物源性饲料的PCR扩增分析。结果显示该方法与GuSCN法、SDS法同样理想,从而实现了对进境饲料的快速检定的要求。该方法检测灵敏度达到牛成分含量为0．1％的水平,具有简单、快捷、灵敏度高的优点。