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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2008

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Abstract

This paper discusses the monitoring network for diffuse pollution from agriculture in Estonia in the context of implementation of the EU Water Framework Directive (WFD) and the Nitrate Directive (ND). Seven surface water monitoring stations in agricultural catchments represent two out of three river basin districts designated in Estonia according to the WFD criteria. The national monitoring programme of ground water quality involves 516 stations of which about half were monitored in 2005. The monitoring sites cover all main ground water bodies in Estonia but are largely concentrated in the Nitrate Vulnerable Zone (NVZ). Analyses did not reveal any significant trends in total nitrogen (TN) and total phosphorus (TP) concentrations in studied rivers during the last 15 years except in one site. The ground water quality stabilised after decrease of nitrate concentrations in the early 1990s, especially in the south part of the NVZ, but even in 2005 the nitrate concentration exceeded 50 mg l1 in 42 out of 145 ground water samples in this region. The existing surface water quality monitoring network provides only restricted information to select between different management options when implementing action programmes for the NVZ and the river basin management plans (RBMP) under the WFD.

Abstract

Over the past years considerable efforts have been made to improve the quality of laboratory analyses in the various monitoring programmes within the framework of the ICP Forests programme. The Soil and Soil Solution, Deposition and Foliage and Litterfall expert panels have carried out a number of ring tests and held discussions on quality control. The expert panels’ subgroup, \"Working Group on QA/QC in Laboratories\", has extended its activities from the quality control of water analyses to encompass all forms of laboratory analysis, and now also includes experts in the fields of soil, foliage and litterfall. This paper presents all the quality control methods that have been devised for the relevant fields of analytical chemistry. The aim is to provide those laboratories carrying out analyses within the ICP Forests programme with a complete overview of the possibilities of applying quality control in their laboratories.

Abstract

A Working Group on Quality Assurance/Quality Control of analyses in laboratories active in the chemical analysis of atmospheric deposition and soil water has been created within the framework of the Integrated Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (UN-ECE/ICP Forests) and the EU/Forest Focus Programme (Regulation 2152/2003). This paper is a follow up to an earlier paper dealing with the validation of chemical analyses, in which validation techniques (ion balance, comparison between measured and calculated conductivity, Na/Cl ratio and relationship between different forms of N) were tested on a set of real analysis data obtained from different laboratories. This paper focuses on the validation of chemical analysis of samples containing high dissolved organic carbon (DOC) concentrations ( 5 mg C L-1), where the ion balance criterion fails because of the presence of weak organic acids. About 6000 chemical analyses of bulk open field, throughfall and stemflow samples, which contained complete sets of all ion concentrations, conductivity and DOC, produced in 8 different laboratories, were used to calculate empirical relationships between DOC and the difference between the sum of cations and the sum of anions, with the aim to evaluate a formal charge per mg of organic C...

Abstract

Agrobacterium-mediated transformation for poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2-3.5%) was revealed. Stable integration of transgenes into the poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the poinsettia genome were found among transformants. Transgenic poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated.