Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Verbetering lichtinval winterlicht : Improving the availability of natural light in winter
    Kempkes, F.L.K. ; Swinkels, G.L.A.M. ; Hemming, S. - \ 2015
    Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1375) - 55
    glastuinbouw - kasgewassen - kastechniek - constructie - natuurlijk licht - lichtdoorlating - condenseren - diffuus glas - greenhouse horticulture - greenhouse crops - greenhouse technology - construction - natural light - light transmission - condensation - diffused glass
    In winter at northern latitudes light is the limiting factor for crop growth. The design of the Venlo greenhouse has not changed for many years although the development of diffuse glass and use of Anti Reflection coatings were only recent. This report shows results of Ray-tracing calculations of the effect of several measures as roof slope, ridge orientation, symmetry of the roof, reflection of the construction elements and the effect of condensation on light transmission of the greenhouse. Results show that it is possible to increase light transmission by more than 10% in case a combination of measures are taken. Effects of standard glass on transmission are higher than with diffuse glass. The measurements on the effect of condensation shows a hugh variation but in average condensation can cost you light, 2% (standard glass) but can gain light as well, up to 6%. Economic feasibility and restrictions in constructions are not taken into account. The optimal winter light greenhouse means a complete re-design of the Venlo type greenhouse cover.
    Tomatenteelt in de hooggeïsoleerde VenLow Energy Kas
    Zwart, H.F. de; Janse, J. ; Kempkes, F.L.K. - \ 2015
    Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1366) - 34
    glastuinbouw - kastechniek - tomaten - solanum lycopersicum - energiebesparing - energiegebruik - kassen - constructie - isolatie (insulation) - ontvochtiging - doelstellingen - haalbaarheidsstudies - greenhouse horticulture - greenhouse technology - tomatoes - solanum lycopersicum - energy saving - energy consumption - greenhouses - construction - insulation - dehumidification - objectives - feasibility studies
    In the research program Greenhouse as Energy Source aims at having energy-neutral operated greenhouses by 2020. Therefore, a reduction of the energy use is important. The highly insulated VenLow Energy greenhouse have shown a low energy consumption for several years and in 2014 it was attempted to bring it below 10 m³ of natural gas equivalents per m² without a lowered production. To achieve this the leakage had to be reduced further and the screen quality was improved and a high humidity control setpoint was accepted. This in order to reduce the evaporation. Also the manipulation of the EC in the slab could lower the crop transpiration related energy consumption. The experiment showed an energy consumption of 8 m³/m² per year without a decreased crop production. This is far below target, but 2014 was a historically warm year. However, simulations showed that even in an average Dutch year the measurements taken would have met the target. The manipulation of the EC of the slab worked adversely, meaning that it increased the crop transpiration. The conclusion reads that the measures taken in the greenhouse make a productive tomato crop with less than 10 m³ of gas equivalents per m² per year realistic. With respect to the climate, a high humidity must be accepted and a shortened growing season running from mid-January to late November. A tomato variety like Komeett will yield at least 70 kg/m² can be expected, providing that CO2 dosing is not related to gas consumption for heating.
    Grassroots scalar politics: Insights from peasant water struggles in the Ecuadorian and Peruvian Andes
    Hoogesteger van Dijk, J.D. ; Verzijl, A. - \ 2015
    Geoforum 62 (2015). - ISSN 0016-7185 - p. 13 - 23.
    irrigation system - user organizations - latin-america - governance - ecology - bolivia - justice - rights - construction - reflections
    Based on insights from peasant and indigenous communities’ struggles for water in Andean Peru and Ecuador, in this article we argue that the defense of grassroots interests -and with it the advancement of more equitable governance- greatly hinges on the capacity of these groups to engage in grassroots scalar politics. With increasing pressure on water resources in the Andes, the access to water of many rural peasant and indigenous communities is being threatened. The growing realization that their access to water and related interests are embedded in broader regional and national politics, legal frameworks and water policies, has led many communities and peasant water user associations to engage in networks and create alliances with other water users, governmental institutions and non-governmental actors. To better understand these (and other) grassroots struggles and strategies, in this contribution we develop the concept of grassroots scalar politics, which we use as a lens to analyze two case studies. In Ecuador we present how water users of the province of Chimborazo have defended their interests through the consolidation of the Provincial Water Users Associations’ Federation Interjuntas-Chimborazo and its networks. Then we focus on how with the support of Interjuntas-Chimborazo the Water Users Association of the Chambo irrigation system defended their historical water allocation. In Peru we analyze the conformation and achievements of the federative Water Users Association of Ayacucho (JUDRA) and present how the community of Ccharhuancho in the region of Huancavelica, managed to defend its waters and territory against the coastal irrigation sector of Ica
    Seal monitoring and evaluation for the Luchterduinen offshore wind farm: 2. Tconstruction - 2014 report
    Kirkwood, R.J. ; Aarts, G.M. ; Brasseur, S.M.J.M. - \ 2015
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C152/14) - 65
    zeehonden - habitats - halichoerus grypus - phoca vitulina - menselijke invloed - windmolenpark - constructie - monitoring - ecologische verstoring - noordzee - zuid-holland - seals - habitats - halichoerus grypus - phoca vitulina - human impact - wind farms - construction - monitoring - ecological disturbance - north sea - zuid-holland
    Two seal species live in Dutch waters: the harbour seal (Phoca vitulina) and the grey seal (Halichoerus grypus). They occupy land-based sites (haul-outs) in both the Wadden Sea and the Delta region, and move between these regions along the North Sea coastal zone. Human activities, such as construction of a wind farm in this zone, may influence movement and use of the zone by the seals. Monitoring of potential impacts on seals to Luchterduinen construction was required in the permit to construct. The Luchterduinen offshore wind farm is the third wind farm development in the Dutch North Sea coastal zone (between Den Helder and Rotterdam). Pile-driving of the turbine towers occurred between 31 July and 16 October, 2014. Seals exposed to pile-driving, even at close distances of
    Development of a leafy Brassica rapa fixed line collection for genetic diversity and population structure analysis
    Pang, W. ; Li, X. ; Choi, S.R. ; Dhandapani, V. ; Im, S. ; Park, M.Y. ; Jang, C.S. ; Yang, M.S. ; Ham, I.K. ; Lee, E.M. ; Kim, W. ; Lee, S.S. ; Bonnema, A.B. ; Park, S. ; Piao, Z. ; Lim, Y.P. - \ 2015
    Molecular Breeding 35 (2015)1. - ISSN 1380-3743
    genome sequencing project - microspore culture - linkage map - napus l. - microsatellite markers - repeat markers - construction - crop - association - centers
    Brassica rapa is an economically important crop with a wide range of morphologies. Developing a set of fixed lines and understanding their diversity has been challenging, but facilitates resource conservation. We investigated the genetic diversity and population structure of 238 fixed lines of leafy B. rapa with 45 new simple sequence repeat markers and 109 new NGS (next-generation sequencing)-generated single nucleotide polymorphism markers evenly distributed throughout the B. rapa genome. Phylogenetic analysis classified the vegetable fixed lines into four subgroups, with the three oil types forming a separate and relatively distant cluster. A model-based population structure analysis identified four subpopulations corresponding to geographical origins and morphological traits, and revealed extensive allelic admixture. In particular, the Chinese cabbage cluster was subdivided into three groups and showed considerable correlation with leaf- and heading-related traits (leaf and heading shape). The vegetable B. rapa fixed lines successfully developed in our study could be valuable materials for establishing a multinational Brassica rapa diversity resource. Understanding the genetic diversity and population structure could be useful for utilization of the representative genetic variation and further genomic analysis.
    Insecten in je achtertuin (2) Praktisch: Zo krijg je meer vlinders en bijen in je tuin
    Alebeek, Frans van - \ 2015
    insects - apidae - lepidoptera - biotopes - habitats - gardens - construction - knowledge - biodiversity
    Efficient development of highly polymorphic microsatellite markers based on polymorphic repeats in transcriptome sequences of multiple individuals
    Vukosavljev, M. ; Esselink, G. ; Westende, W.P.C. van 't; Cox, P. ; Visser, R.G.F. ; Arens, P. ; Smulders, M.J.M. - \ 2015
    Molecular Ecology Resources 15 (2015)1. - ISSN 1755-098X - p. 17 - 27.
    est-ssr markers - genetic-linkage maps - in-silico - rose - l. - diversity - transferability - construction - variability - identification
    The first hurdle in developing microsatellite markers, cloning, has been overcome by next generation sequencing. The second hurdle is testing to differentiate polymorphic from non-polymorphic loci. The third hurdle, somewhat hidden, is that only polymorphic markers with a large effective number of alleles are sufficiently informative to be deployed in multiple studies. Both steps are laborious and still done manually. We have developed a strategy in which we first screen reads from multiple genotypes for repeats that show the most length variants, and only these are subsequently developed into markers. We validated our strategy in tetraploid garden rose using Illumina paired-end transcriptome sequences of 11 roses. Out of 48 tested two markers failed to amplify but all others were polymorphic. Ten loci amplified more than one locus, indicating duplicated genes or gene families. Completely avoiding duplicated loci will be difficult because the range of numbers of predicted alleles of highly polymorphic single- and multi-locus markers largely overlapped. Of the remainder, half were replicate markers (i.e., multiple primer pairs for one locus), indicating the difficulty of correctly filtering short reads containing repeat sequences. We subsequently refined the approach to eliminate multiple primer sets to the same loci. The remaining 18 markers were all highly polymorphic, amplifying on average 11.7 alleles per marker (range = 6 to 20) in 11 tetraploid roses, exceeding the 8.2 alleles per marker of the 24 most polymorphic markers genotyped previously. This strategy, therefore, represents a major step forward in the development of highly polymorphic microsatellite markers.
    Effect of pile-driving sound on the survival of fish larvae.
    Bolle, L.J. ; Jong, C.A.F. ; Blom, E. ; Wessels, P.W. ; Damme, C.J.G. van; Winter, H.V. - \ 2014
    IJmuiden : IMARES (Report / IMARES Wageningen UR C182/14) - 33
    larven - vissen - geluidshinder - onderwaterakoestiek - offshore - constructie - windmolenpark - nederland - dierenwelzijn - larvae - fishes - noise pollution - underwater acoustics - offshore - construction - wind farms - netherlands - animal welfare
    Er bestaat zorg over de mogelijk schadelijk effecten van onderwatergeluid gegenereerd gedurende het heien bij de aanleg van offshore windparken. Harde impulsgeluiden zoals heigeluid kunnen dodelijke verwondingen veroorzaken bij vissen. Tot voor kort was er weinig bekend over de geluidsniveaus waarbij fysieke schade optreedt. Wij hebben letale effecten van blootstelling aan heigeluid onderzocht in verschillende larvale stadia van drie vissoorten (tong Solea solea, zeebaars Dicentrarchus labrax en haring Clupea harengus). De experimenten zijn uitgevoerd met de ‘larvaebrator’, een apparaat dat ontwikkeld is om larven bloot te kunnen stellen aan heigeluid in het laboratorium.
    Possibilities and challenges of the potato genome sequence
    Visser, R.G.F. ; Bachem, C.W.B. ; Borm, T.J.A. ; Boer, J.M. de; Eck, H.J. van; Finkers, H.J. ; Linden, G. van der; Maliepaard, C.A. ; Uitdewilligen, J.G.A.M.L. ; Voorrips, R.E. ; Vos, P.G. ; Wolters, A.M.A. - \ 2014
    Potato Research 57 (2014)3-4. - ISSN 0014-3065 - p. 327 - 330.
    This paper describes the progress that has been made since the draft genome sequence of potato has been obtained and the analyses that need to be done to make further progress. Although sequencing has become less expensive and read lengths have increased, making optimal use of the information obtained is still difficult, certainly in the tetraploid potato crop. Major challenges in potato genomics are standardized genome assembly and haplotype analysis. Sequencing methods need to be improved further to achieve precision breeding. With the current new generation sequencing technology, the focus in potato breeding will shift from phenotype improvement to genotype improvement. In this respect, it is essential to realize that different alleles of the same gene can lead to different phenotypes depending on the genetic background and that there is significant epistatic interaction between different alleles. Genome-wide association studies will gain statistical power when binary single nucleotide polymorphism (SNP) data can be replaced with multi-allelic haplotype data. Binary SNP can be distributed across the many different alleles per locus or may be haplotype-specific, and potentially tag specific alleles which clearly differ in their contribution to a certain trait value. Assembling reads from the same linkage phase proved to allow constructing sufficiently long haplotype tracts to ensure their uniqueness. Combining large phenotyping data sets with modern approaches to sequencing and haplotype analysis and proper software will allow the efficiency of potato breeding to increase.
    Identifying the methodological characteristics of European green city rankings
    Meijering, J.V. ; Kern, K. ; Tobi, H. - \ 2014
    Ecological Indicators 43 (2014). - ISSN 1470-160X - p. 132 - 142.
    quality-of-life - environmental sustainability - composite indicators - urban areas - construction - pitfalls - indexes
    City rankings that aim to measure the environmental sustainability of European cities may contribute to the evaluation and development of environmental policy of European cities. The objective of this study is to identify and evaluate the methodological characteristics of these city rankings. First, a methodology was developed to systematically identify methodological characteristics of city rankings within different steps of the ranking development process. Second, six city rankings European Energy Award, European Green Capital Award, European Green City Index, European Soot-free City Ranking, RES Champions League, Urban Ecosystem Europe were examined. Official websites and any methodological documents found on those websites were content analyzed using the developed methodology. Interviews with representatives of the city rankings were conducted to acquire any additional information. Results showed that the city rankings varied greatly with respect to their methodological characteristics and that all city rankings had methodological weaknesses. Developers of city rankings are advised to use the methodology developed in this study to find methodological weaknesses and improve their ranking. In addition, developers ought to be more transparent about the methodological characteristics of their city rankings. End-users of city rankings are advised to use the developed methodology to identify and evaluate the methodological characteristics of city rankings before deciding to act on ranking results.
    Development and validation of a 20K Single Nucleotide Polymorphism (SNP) whole genome genotyping array for apple (Malus × domestica Borkh)
    Bianco, L. ; Cestaro, A. ; Sargent, D.J. ; Guardo, M. Di; Jansen, J. ; Weg, W.E. van de - \ 2014
    PLoS ONE 9 (2014)10. - ISSN 1932-6203 - 9 p.
    linkage map - construction - cultivars - alignment - accurate - barley
    High-density SNP arrays for genome-wide assessment of allelic variation have made high resolution genetic characterization of crop germplasm feasible. A medium density array for apple, the IRSC 8 K SNP array, has been successfully developed and used for screens of bi-parental populations. However, the number of robust and well-distributed markers contained on this array was not sufficient to perform genome-wide association analyses in wider germplasm sets, or Pedigree-Based Analysis at high precision, because of rapid decay of linkage disequilibrium. We describe the development of an Illumina Infinium array targeting 20 K SNPs. The SNPs were predicted from re-sequencing data derived from the genomes of 13 Malus × domestica apple cultivars and one accession belonging to a crab apple species (M. micromalus). A pipeline for SNP selection was devised that avoided the pitfalls associated with the inclusion of paralogous sequence variants, supported the construction of robust multi-allelic SNP haploblocks and selected up to 11 entries within narrow genomic regions of ±5 kb, termed focal points (FPs). Broad genome coverage was attained by placing FPs at 1 cM intervals on a consensus genetic map, complementing them with FPs to enrich the ends of each of the chromosomes, and by bridging physical intervals greater than 400 Kbps. The selection also included ~3.7 K validated SNPs from the IRSC 8 K array. The array has already been used in other studies where ~15.8 K SNP markers were mapped with an average of ~6.8 K SNPs per full-sib family. The newly developed array with its high density of polymorphic validated SNPs is expected to be of great utility for Pedigree-Based Analysis and Genomic Selection. It will also be a valuable tool to help dissect the genetic mechanisms controlling important fruit quality traits, and to aid the identification of marker-trait associations suitable for the application of Marker Assisted Selection in apple breeding programs.
    2SaveEnergy® kasconcept: van design naar realisatie
    Kempkes, F.L.K. ; Deursen, A. van - \ 2014
    glastuinbouw - kassen - constructie - innovaties - energiebesparing - lichtregiem - lichtdoorlating - economische analyse - greenhouse horticulture - greenhouses - construction - innovations - energy saving - light regime - light transmission - economic analysis
    De doelstelling van dit onderzoek is de ontwikkeling en realisatie van een kasconcept dat een potentieel hoge energie besparing kan bereiken zonder dat dit ten koste gaat van de productie en of productkwaliteit bij een beperkt investeringsniveau.
    Governance van innovatieve dijkconcepten in de Zuidwestelijke Delta : handreiking voor projecten die veiligheid, economie en ecologie van een dijkzone combineren
    Groot, A.M.E. ; Leeuwen, C.J. van; Tangelder, M. ; Timmerman, J.G. ; Werners, S.E. ; Loon-Steensma, J.M. van - \ 2014
    Wageningen : Alterra (Alterra-rapport 2506) - 62
    dijken - constructie - klimaatverandering - governance - innovaties - landgebruik - dykes - construction - climatic change - governance - innovations - land use
    In het Deltaprogramma Zuidwestelijke Delta wordt op het moment gewerkt aan strategieën om de gevolgen van klimaatverandering op waterveiligheid en zoetwater op te vangen. Ter ondersteuning bij het formuleren van kansrijke strategieën (2014) wordt sinds 2011 voor het Deltaprogramma Zuidwestelijke Delta beleidsondersteunend onderzoek uitgevoerd op het gebied van innovatieve dijkconcepten. Innovatieve dijkconcepten worden in dit onderzoek gedefinieerd als: nieuwe typen waterkeringen of aanpassingen van bestaande waterkeringen die veiligheid bieden tegen overstromingen, of hieraan een bijdrage leveren en tegelijkertijd ook mogelijkheden bieden voor multifunctioneel (mede)gebruik zoals voor recreatie, natuur, visserij en aquacultuur.
    Peasant-driven agricultural growth and food sovereignty
    Ploeg, J.D. van der - \ 2014
    The Journal of Peasant Studies 41 (2014)6. - ISSN 0306-6150 - p. 999 - 1030.
    rural-development - self-employment - latin-america - china - agroecosystems - construction - questions - crisis
    The concept of food sovereignty presents us with an important theoretical and practical challenge. The political economy of agriculture can only take up this gauntlet through improving its understanding of the processes of agricultural growth. It is very difficult to address the issue of food sovereignty without such an understanding. Developing such an understanding involves (re)combining the political economy of agriculture with the Chayanovian approach. This paper gives several explanations (all individually valid but stronger in combination) as to why peasant agriculture results in sturdy and sustainable growth and also identifies the factors that undermine this capacity. The paper also argues that peasant agriculture is far from being a remnant of the past. While different peasantries around the world are shaped and reproduced by today's capital (and more specifically by current food empires), they equally help to shape and contribute to the further unfolding of the forms of capital related to food and agriculture. It is important to understand this two-way interaction between capital and peasant agriculture as this helps to ground the concept of food sovereignty. The article argues that the capacity to produce enough food (at different levels, distinguishing different needs, and so on) needs to be an integral part of the food sovereignty discourse. It concludes by suggesting that peasant agriculture has the best potential for meeting food sovereignty largely because it has the capacity to produce (more than) sufficient good food for the growing world population and that it can do so in a way that is sustainable.
    Genetic diversity of Vietnamese domestic chicken populations as decision-making support for conservation strategies
    Pham, H.T.M. ; Berthouly-Salazar, C. ; Crooijmans, R.P.M.A. - \ 2013
    Animal Genetics 44 (2013)5. - ISSN 0268-9146 - p. 509 - 521.
    multilocus genotype data - breeds - program - microsatellites - construction - resources - inference - software - ecotypes - alleles
    The aims of this study were to assess the genetic diversity of 17 populations of Vietnamese local chickens (VNN) and one Red Jungle Fowl population, together with six chicken populations of Chinese origin (CNO), and to provide priorities supporting the conservation of genetic resources using 20 microsatellites. Consequently, the VNN populations exhibited a higher diversity than did CNO populations in terms of number of alleles but showed a slightly lower observed heterozygosity. The VNN populations showed in total seven private alleles, whereas no CNO private alleles were found. The expected heterozygosity of 0.576 in the VNN populations was higher than the observed heterozygosity of 0.490, leading to heterozygote deficiency within populations. This issue could be partly explained by the Wahlund effect due to fragmentation of several populations between chicken flocks. Molecular analysis of variance showed that most of genetic variation was found within VNN populations. The Bayesian clustering analysis showed that VNN and CNO chickens were separated into two distinct groups with little evidence for gene flow between them. Among the 24 populations, 13 were successfully assigned to their own cluster, whereas the structuring was not clear for the remaining 11 chicken populations. The contributions of 24 populations to the total genetic diversity were mostly consistent across two approaches, taking into account the within- and between-populations genetic diversity and allelic richness. The black H'mong, Lien Minh, Luong Phuong and Red Jungle Fowl were ranked with the highest priorities for conservation according to Caballero and Toro's and Petit's approaches. In conclusion, a national strategy needs to be set up for Vietnamese chicken populations, with three main components: conservation of high-priority breeds, within-breed management with animal exchanges between flocks to avoid Wahlund effect and monitoring of inbreeding rate.
    Linkage mapping in the oilseed crop Jatropha curcas L. reveals a locus controlling the biosynthesis of phorbol esters which cause seed toxicity
    King, A.J. ; Montes, L.R. ; Clarke, J.G. ; Affleck, J. ; Li, Y. ; Witsenboer, H. ; Vossen, E. van der; Linde, P. van der; Tripathi, Y. ; Tavares, E. ; Shukla, P. ; Rajasekaran, T. ; Loo, E.N. van; Graham, I.A. - \ 2013
    Plant Biotechnology Journal 11 (2013)8. - ISSN 1467-7644 - p. 986 - 996.
    transcriptome analysis - genetic diversity - biofuel plant - genome - oil - markers - qtl - construction - sequence - maps
    Current efforts to grow the tropical oilseed crop Jatropha curcas L. economically are hampered by the lack of cultivars and the presence of toxic phorbol esters (PE) within the seeds of most provenances. These PE restrict the conversion of seed cake into animal feed, although naturally occurring ‘nontoxic’ provenances exist which produce seed lacking PE. As an important step towards the development of genetically improved varieties of J. curcas, we constructed a linkage map from four F2 mapping populations. The consensus linkage map contains 502 codominant markers, distributed over 11 linkage groups, with a mean marker density of 1.8 cM per unique locus. Analysis of the inheritance of PE biosynthesis indicated that this is a maternally controlled dominant monogenic trait. This maternal control is due to biosynthesis of the PE occurring only within maternal tissues. The trait segregated 3 : 1 within seeds collected from F2 plants, and QTL analysis revealed that a locus on linkage group 8 was responsible for phorbol ester biosynthesis. By taking advantage of the draft genome assemblies of J. curcas and Ricinus communis (castor), a comparative mapping approach was used to develop additional markers to fine map this mutation within 2.3 cM. The linkage map provides a framework for the dissection of agronomic traits in J. curcas, and the development of improved varieties by marker-assisted breeding. The identification of the locus responsible for PE biosynthesis means that it is now possible to rapidly breed new nontoxic varieties.
    Geboeid door het verleden: de Bocht van Barkman
    Schaminee, J.H.J. ; Ozinga, W.A. - \ 2013
    Stratiotes 2013 (2013)44. - ISSN 0928-2297 - p. 13 - 18.
    plantengemeenschappen - vegetatietypen - historische ecologie - infrastructuur - constructie - structurele aanpassing - twente - plant communities - vegetation types - historical ecology - infrastructure - construction - structural adjustment
    Geboeid door het verleden is de titel van een onlangs verschenen boek in de reeks 'Vegetatiekundige Monografieën', dat de historische ecologie tot onderwerp heeft. Onder deze titel willen we in Stratiotes op gezette tijden ruimte bieden aan min of meer vergeten of minder bekende maar interessante onderwerpen uit het rijke verleden van het vegetatieonderzoek in ons land. In deze bijdrage aandacht voor een gewijzigde tracé bij de aanleg van de snelweg A1. In de zeventiger jaren voerde prof. Barkman met succes actie tegen de aanvankelijk geplande route, dwars door een natuurreservaat met opvallende jenerbesstruwelen
    Pilotstudie Groene Dollard Dijk : een verkenning naar de haalbaarheid van een brede groene dijk met flauw talud en een voorland van kwelders
    Loon-Steensma, J.M. van; Schelfhout, H.A. ; Reintsema, R. ; Jolink, E. ; Leij, H. van der - \ 2013
    Wageningen : Alterra (Alterra-rapport 2437) - 102
    dijken - constructie - hellingshoek - haalbaarheidsstudies - graslanden - wetlands - oost-groningen - dykes - construction - angle of repose - feasibility studies - grasslands - wetlands - oost-groningen
    In dit rapport worden de mogelijkheden voor een Groene Dollard Dijk verkend. Deze dijken hebben een met gras bekleed flauw buitentalud dat op natuurlijke wijze overgaat in de voorliggende kwelders. Door het golfreducerend vermogen van het kweldervoorland en een verflauwd dijktalud, is er geen harde bekleding nodig op het buitentalud. Het waterschap wil de Groene Dollard Dijk graag als (voorkeurs)variant meenemen in de MER-procedure voor de komende dijkversterking. Het blijkt dat een brede groene dijk weliswaar meer ruimte vraagt, maar toch nog binnen de huidige beheerzone van de dijk kan worden gerealiseerd. Wel zijn er nog diverse vragen over mogelijkheden om de benodigde grond op een duurzame en natuurvriendelijke manier te winnen, het effect van de brede groene dijk op natuurwaarden, de aanleg- en beheerkosten en het draagvlak.
    Tomato breeding in the genomics era: insights from a SNP array
    Víquez-Zamora, M. ; Vosman, B. ; Geest, H. van; Bovy, A.G. ; Visser, R.G.F. ; Finkers, H.J. ; Heusden, A.W. van - \ 2013
    BMC Genomics 14 (2013). - ISSN 1471-2164 - 28 p.
    backcross qtl analysis - phylogenetic-relationships - lycopersicon-hirsutum - evolutionary history - essential derivation - genus lycopersicon - l-pimpinellifolium - dna - construction - technologies
    Background - The major bottle neck in genetic and linkage studies in tomato has been the lack of a sufficient number of molecular markers. This has radically changed with the application of next generation sequencing and high throughput genotyping. A set of 6000 SNPs was identified and 5528 of them were used to evaluate tomato germplasm at the level of species, varieties and segregating populations. Results - From the 5528 SNPs, 1980 originated from 454-sequencing, 3495 from Illumina Solexa sequencing and 53 were additional known markers. Genotyping different tomato samples allowed the evaluation of the level of heterozygosity and introgressions among commercial varieties. Cherry tomatoes were especially different from round/beefs in chromosomes 4, 5 and 12. We were able to identify a set of 750 unique markers distinguishing S. lycopersicum 'Moneymaker' from all its distantly related wild relatives. Clustering and neighbour joining analysis among varieties and species showed expected grouping patterns, with S. pimpinellifolium as the most closely related to commercial tomatoesearlier results. Conclusions - Our results show that a SNP search in only a few breeding lines already provides generally applicable markers in tomato and its wild relatives. It also shows that the Illumina bead array generated data are highly reproducible. Our SNPs can roughly be divided in two categories: SNPs of which both forms are present in the wild relatives and in domesticated tomatoes (originating from common ancestors) and SNPs unique for the domesticated tomato (originating from after the domestication event). The SNPs can be used for genotyping, identification of varieties, comparison of genetic and physical linkage maps and to confirm (phylogenetic) relations. In the SNPs used for the array there is hardly any overlap with the SolCAP array and it is strongly recommended to combine both SNP sets and to select a core collection of robust SNPs completely covering the entire tomato genome
    Pilotproject voor het gebruik van onderwater-geluidloggers voor het monitoren van omgevingsfactoren
    Lucke, K. - \ 2012
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C152/12) - 45
    geluid - onderwaterakoestiek - geluidsleer - geluidsopnames - constructie - zeezoogdieren - noise - underwater acoustics - acoustics - recordings - construction - marine mammals
    Om onderwatergeluid op te kunnen nemen, zijn in de winter van 2011/2012 voor een periode van meer dan drie maanden twee geluidsloggers geplaatst in de Eems. De locaties zijn zo gekozen dat één van de recorders vlakbij de ingang van de Eemshaven hangt, terwijl de andere vlakbij de zandbank Hond & Paap gesitueerd is. Het doel van dit pilotproject is het testen van de bruikbaarheid van de techniek om geluidsuitstoot, van zowel bouwgerelateerde activiteiten bij de Eemshaven als niet aan de bouw gerelateerde activiteiten, te identificeren en deze te koppelen aan de gerapporteerde tijdsinformatie van de bouwactiviteiten. De opnames lieten zien dat het niveau van het achtergrondgeluid in de Eems vooral vanwege de sterke stroming relatief hoog is. Passerende Scheepvaart op de Eems bleek de grootste bijdrage te leveren aan het totale onderwatergeluid ter plaatse van de geluidsloggers, waarbij dit geluid verschillende keren bouwgerelateerde activiteiten maskeerde. Het resultaat laat zien dat verschillende typen geluidsbronnen, naast de scheepvaart op de Eems, met zekerheid konden worden geïdentificeerd.
    A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs
    Guyon, R. ; Rakotomanga, M. ; Azzouzi, N. ; Coutanceau, J.P. ; Bonillo, C. ; Cotta, H. D'; Pepey, E. ; Soler, L. ; Rodier-Goud, M. ; Hont, A. D'; Conte, M.A. ; Bers, N.E.M. van; Penman, D.J. ; Hitte, C. ; Crooijmans, R.P.M.A. ; Kocher, T.D. ; Ozouf-Costaz, C. ; Baroiller, J.F. ; Galibert, F. - \ 2012
    BMC Genomics 13 (2012). - ISSN 1471-2164
    radiation hybrid map - genetic-linkage map - oreochromis-niloticus - sex determination - tetraodon-nigroviridis - zebrafish genome - fish - sequence - construction - evolution
    Background: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC end sequences and ESTs, but comparative genome analysis and maps of quantitative trait loci (QTL) are still limited. Results: We have constructed a high-resolution radiation hybrid (RH) panel for the Nile tilapia and genotyped 1358 markers consisting of 850 genes, 82 markers corresponding to BAC end sequences, 154 microsatellites and 272 single nucleotide polymorphisms (SNPs). From these, 1296 markers could be associated in 81 RH groups, while 62 were not linked. The total size of the RH map is 34,084 cR(3500) and 937,310 kb. It covers 88% of the entire genome with an estimated inter-marker distance of 742 Kb. Mapping of microsatellites enabled integration to the genetic map. We have merged LG8 and LG24 into a single linkage group, and confirmed that LG16-LG21 are also merged. The orientation and association of RH groups to each chromosome and LG was confirmed by chromosomal in situ hybridizations (FISH) of 55 BACs. Fifty RH groups were localized on the 22 chromosomes while 31 remained small orphan groups. Synteny relationships were determined between Nile tilapia, stickleback, medaka and pufferfish. Conclusion: The RH map and associated FISH map provide a valuable gene-ordered resource for gene mapping and QTL studies. All genetic linkage groups with their corresponding RH groups now have a corresponding chromosome which can be identified in the karyotype. Placement of conserved segments indicated that multiple inter-chromosomal rearrangements have occurred between Nile tilapia and the other model fishes. These maps represent a valuable resource for organizing the forthcoming genome sequence of Nile tilapia, and provide a foundation for evolutionary studies of East African cichlid fishes.
    Reverse breeding in Arabidopsis thaliana generates homozygous parental lines from a heterozygous plant
    Wijnker, T.G. ; Dun, K.P.M. van; Snoo, C.B. ; Lelivelt, C.L.C. ; Keurentjes, J.J.B. ; Naharudin, N.S. ; Ravi, M. ; Chan, S.W.L. ; Jong, J.H.S.G.M. de; Dirks, R. - \ 2012
    Nature Genetics 44 (2012). - ISSN 1061-4036 - p. 467 - 470.
    genome - dna - construction - meiosis - genes - rflp - map
    Traditionally, hybrid seeds are produced by crossing selected inbred lines. Here we provide a proof of concept for reverse breeding, a new approach that simplifies meiosis such that homozygous parental lines can be generated from a vigorous hybrid individual. We silenced DMC1, which encodes the meiotic recombination protein DISRUPTED MEIOTIC cDNA1, in hybrids of A. thaliana, so that non-recombined parental chromosomes segregate during meiosis. We then converted the resulting gametes into adult haploid plants, and subsequently into homozygous diploids, so that each contained half the genome of the original hybrid. From 36 homozygous lines, we selected 3 (out of 6) complementing parental pairs that allowed us to recreate the original hybrid by intercrossing. In addition, this approach resulted in a complete set of chromosome-substitution lines. Our method allows the selection of a single choice offspring from a segregating population and preservation of its heterozygous genotype by generating homozygous founder lines
    Development of a dense SNP-based linkage map of an apple rootstock progeny using the Malus Infinium whole genome genotyping array
    Antanaviciute, L. ; Fernández-Fernández, F. ; Jansen, J. ; Banchi, E. ; Evans, K.M. ; Viola, R. ; Velasco, R. ; Dunwell, J.M. ; Troggio, M. ; Sargent, D.J. - \ 2012
    BMC Genomics 13 (2012). - ISSN 1471-2164
    domestica borkh. - construction - alleles
    Background: A whole-genome genotyping array has previously been developed for Malus using SNP data from 28 Malus genotypes. This array offers the prospect of high throughput genotyping and linkage map development for any given Malus progeny. To test the applicability of the array for mapping in diverse Malus genotypes, we applied the array to the construction of a SNP-based linkage map of an apple rootstock progeny. Results: Of the 7,867 Malus SNP markers on the array, 1,823 (23.2%) were heterozygous in one of the two parents of the progeny, 1,007 (12.8%) were heterozygous in both parental genotypes, whilst just 2.8% of the 921 Pyrus SNPs were heterozygous. A linkage map spanning 1,282.2 cM was produced comprising 2,272 SNP markers, 306 SSR markers and the S-locus. The length of the M432 linkage map was increased by 52.7 cM with the addition of the SNP markers, whilst marker density increased from 3.8 cM/marker to 0.5 cM/marker. Just three regions in excess of 10 cM remain where no markers were mapped. We compared the positions of the mapped SNP markers on the M432 map with their predicted positions on the 'Golden Delicious' genome sequence. A total of 311 markers (13.7% of all mapped markers) mapped to positions that conflicted with their predicted positions on the 'Golden Delicious' pseudo-chromosomes, indicating the presence of paralogous genomic regions or mis-assignments of genome sequence contigs during the assembly and anchoring of the genome sequence. Conclusions: We incorporated data for the 2,272 SNP markers onto the map of the M432 progeny and have presented the most complete and saturated map of the full 17 linkage groups of M. pumila to date. The data were generated rapidly in a high-throughput semi-automated pipeline, permitting significant savings in time and cost over linkage map construction using microsatellites. The application of the array will permit linkage maps to be developed for QTL analyses in a cost-effective manner, and the identification of SNPs that have been assigned erroneous positions on the 'Golden Delicious' reference sequence will assist in the continued improvement of the genome sequence assembly for that variety.
    Random and cyclical deletion of large DNA segments in the genome of Pseudomonas putida
    Leprince, A. ; Lorenzo, V. de; Völler, P. ; Passel, M.W.J. van; Martins Dos Santos, V.A.P. - \ 2012
    Environmental Microbiology 14 (2012)6. - ISSN 1462-2912 - p. 1444 - 1453.
    escherichia-coli genome - kt2440 - construction - sequence - system - genes - biodegradation - phenotypes - selection - insights
    Cumulative site-directed mutagenesis is of limited suitability for the global analysis of the gene functions in the microbe's cellular network. In order to simplify and stabilize the genome of the soil bacterium Pseudomonas putida, we developed a recyclable three-step excision method based on the combination of customized mini-transposons and the FLP-FRT site-specific recombination system. To demonstrate the powerful potential of these tools, we first established insertion mutant libraries that allow users to study gene functions with respect either to phenotypic characteristics (single insertions) or to their involvement in predicted networks (double insertions). Based on these libraries, we generated as a proof-of-principle, single-deletion mutants lacking ~ 4.1% of the genome (~ 3.7% of the gene repertoire). A cyclical application of the method generated four double-deletion mutants of which a maximum of ~ 7.4% of the chromosome (~ 6.9% of the gene count) was excised. This procedure demonstrates a new strategy for rapid genome streamlining and gain of new insights into the molecular interactions and regulations
    A hybrid BAC physical map of potato: a framework for sequencing a heterozygous genome
    Boer, J.M. de; Borm, T.J.A. ; Jesse, T. ; Brugmans, B.W. ; Tang, X. ; Bryan, G.J. ; Bakker, J. ; Eck, H.J. van; Visser, R.G.F. - \ 2011
    BMC Genomics 12 (2011). - ISSN 1471-2164 - 60 p.
    quantitative trait loci - candidate genes - disease resistance - linkage map - tomato - aflp - solanum - markers - dna - construction
    Background Potato is the world's third most important food crop, yet cultivar improvement and genomic research in general remain difficult because of the heterozygous and tetraploid nature of its genome. The development of physical map resources that can facilitate genomic analyses in potato has so far been very limited. Here we present the methods of construction and the general statistics of the first two genome-wide BAC physical maps of potato, which were made from the heterozygous diploid clone RH89-039-16 (RH). Results First, a gel electrophoresis-based physical map was made by AFLP fingerprinting of 64478 BAC clones, which were aligned into 4150 contigs with an estimated total length of 1361 Mb. Screening of BAC pools, followed by the KeyMaps in silico anchoring procedure, identified 1725 AFLP markers in the physical map, and 1252 BAC contigs were anchored the ultradense potato genetic map. A second, sequence-tag-based physical map was constructed from 65919 whole genome profiling (WGP) BAC fingerprints and these were aligned into 3601 BAC contigs spanning 1396 Mb. The 39733 BAC clones that overlap between both physical maps provided anchors to 1127 contigs in the WGP physical map, and reduced the number of contigs to around 2800 in each map separately. Both physical maps were 1.64 times longer than the 850 Mb potato genome. Genome heterozygosity and incomplete merging of BAC contigs are two factors that can explain this map inflation. The contig information of both physical maps was united in a single table that describes hybrid potato physical map. Conclusions The AFLP physical map has already been used by the Potato Genome Sequencing Consortium for sequencing 10% of the heterozygous genome of clone RH on a BAC-by-BAC basis. By layering a new WGP physical map on top of the AFLP physical map, a genetically anchored genome-wide framework of 322434 sequence tags has been created. This reference framework can be used for anchoring and ordering of genomic sequences of clone RH (and other potato genotypes), and opens the possibility to finish sequencing of the RH genome in a more efficient way via high throughput next generation approaches.
    Perspectives on landscape identity, a conceptual challenge
    Stobbelaar, D.J. ; Pedroli, B. - \ 2011
    Landscape Research 36 (2011)3. - ISSN 0142-6397 - p. 321 - 339.
    place-identity - regional identity - european landscape - community - sense - representation - attachment - construction - perception - diversity
    The concept of landscape identity is often referred to in landscape policy and planning. A clear definition of the concept is lacking however. This is problematic because the term ‘landscape identity’ can have many different meanings and thus easily lead to confusion. We define landscape identity as ‘the perceived uniqueness of a place’ and endeavour to describe the content of this definition more concisely. Within this context the paper introduces the framework of the Landscape Identity Circle for the various dimensions of landscape identity based on two axes: differentiation between spatial as opposed to existential identity, and differentiation between personal and cultural landscape identity. This framework is valuable in positioning research approaches and disciplines addressing landscape identity
    The sociocultural sustainability of livestock farming: an inquiry into social perceptions of dairy farming.
    Boogaard, B.K. ; Oosting, S.J. ; Bock, B.B. ; Wiskerke, J.S.C. - \ 2011
    Animal 5 (2011)9. - ISSN 1751-7311 - p. 1458 - 1466.
    animal-welfare - lay discourses - agriculture - netherlands - systems - construction - environment - consumer - society - ethics
    Over the past 50 years, the scale and intensity of livestock farming have increased significantly. At the same time, Western societies have become more urbanised and fewer people have close relatives involved in farming. As a result, most citizens have little knowledge or direct experience of what farming entails. In addition, more people are expressing concerns over issues such as farm animal welfare. This has led to increasing public demand for more sustainable ways of livestock farming. To date, little research has been carried out on the social pillar of sustainable livestock farming. The aim of this study is to provide insights into the sociocultural sustainability of livestock farming systems. This study reviews the key findings of earlier published interdisciplinary research about the social perceptions of dairy farming in the Netherlands and Norway (Boogaard et al., 2006, 2008, 2010a and 2010b) and synthesises the implications for sociocultural sustainability of livestock farming. This study argues that the (sociocultural) sustainable development of livestock farming is not an objective concept, but that it is socially and culturally constructed by people in specific contexts. It explains the social pillar of the economics/ecological/social model sustainability in terms of the fields of tensions that exist between modernity, traditions and naturality – ‘the MTN knot’ – each of which has positive and negative faces. All three angles of vision can be seen in people's attitudes to dairy farming, but the weight given to each differs between individuals and cultures. Hence, sociocultural sustainability is context dependent and needs to be evaluated according to its local meaning. Moreover, sociocultural sustainability is about people's perceptions of livestock farming. Lay people might perceive livestock farming differently and ascribe different meanings to it than experts do, but their ‘reality’ is just as real. Finally, this study calls for an ongoing collaboration between social and animal scientists in order to develop livestock farming systems that are more socioculturally sustainable.
    Genotype calling in tetraploid species from bi-allelic marker data using mixture models
    Voorrips, R.E. ; Gort, G. ; Vosman, B. - \ 2011
    BMC Bioinformatics 12 (2011). - ISSN 1471-2105 - 11 p.
    microsatellite dna - sect. caninae - genome - potato - configuration - construction - map
    Background: Automated genotype calling in tetraploid species was until recently not possible, which hampered genetic analysis. Modern genotyping assays often produce two signals, one for each allele of a bi-allelic marker. While ample software is available to obtain genotypes (homozygous for either allele, or heterozygous) for diploid species from these signals, such software is not available for tetraploid species which may be scored as five alternative genotypes (aaaa, baaa, bbaa, bbba and bbbb; nulliplex to quadruplex). Results: We present a novel algorithm, implemented in the R package fitTetra, to assign genotypes for bi-allelic markers to tetraploid samples from genotyping assays that produce intensity signals for both alleles. The algorithm is based on the fitting of several mixture models with five components, one for each of the five possible genotypes. The models have different numbers of parameters specifying the relation between the five component means, and some of them impose a constraint on the mixing proportions to conform to Hardy-Weinberg equilibrium (HWE) ratios. The software rejects markers that do not allow a reliable genotyping for the majority of the samples, and it assigns a missing score to samples that cannot be scored into one of the five possible genotypes with sufficient confidence. Conclusions: We have validated the software with data of a collection of 224 potato varieties assayed with an Illumina GoldenGate™ 384 SNP array and shown that all SNPs with informative ratio distributions are fitted. Almost all fitted models appear to be correct based on visual inspection and comparison with diploid samples. When the collection of potato varieties is analyzed as if it were a population, almost all markers seem to be in Hardy- Weinberg equilibrium. The R package fitTetra is freely available under the GNU Public License from http://www. and as Additional files with this article.
    Text, talk, things, and the subpolitics of performing place
    Buizer, I.M. ; Turnhout, E. - \ 2011
    Geoforum 42 (2011)5. - ISSN 0016-7185 - p. 530 - 538.
    politics - participation - construction - governance - identity - policy - space
    This article tells the story of how a group of Dutch and Belgian citizens organized themselves to promote an area that they valued, to put it on the map, to raise awareness about its qualities, and to protect it from urban and industrial development. Our theoretical perspective focuses on the performative and political aspects of this place-making process and the discursive and material practices involved. We connect this to Beck’s concept of subpolitics. Our findings show how the group performed this place not only through text and talk – giving the area a name, using their knowledge and expertise to raise awareness about its values, lobbying and cooperating with decision-makers –, but also through things – installing art objects and information signs that articulate certain characteristics and values of the area. Our findings demonstrate the struggles involved in these performances. The group involved multiple perspectives on what the important values and characteristics of the area are and on what strategies would work best in trying to influence decision-making and protect the area. However, the use of expertise as the main strategy to gain influence excluded the more critical and activist strategies and privileging archaeological and historical values and characteristics came at the expense of attention on agricultural and natural values. Our findings make clear that performing place cannot be taken to be homogeneous and that it inevitably involves multiple perspectives and demands. The struggles, power relations and dynamics of inclusion and exclusion that this multiplicity implicates reveal a form of sub-politics that involves both politicization and depoliticization. Also, it is a form of subpolitics that is more diverse and ambiguous than Beck’s conceptualization presupposes by its emphasis on the role of outsiders as a homogeneous group.
    Energieneutrale sierteelt binnen bereik met DaglichtKas (interview met o.a. Feije de Zwart)
    Bezemer, J. ; Zwart, H.F. de - \ 2011
    Onder Glas 8 (2011)6/7. - p. 56 - 57.
    glastuinbouw - kassen - constructie - beglazing - optische eigenschappen - lichtrelaties - zonnecollectoren - energie - duurzaamheid (sustainability) - sierteelt - potplanten - snijbloemen - greenhouse horticulture - greenhouses - construction - glazing - optical properties - light relations - solar collectors - energy - sustainability - ornamental horticulture - pot plants - cut flowers
    De ontwikkeling van de zogenaamde DaglichtKas is ver gevorderd. Deze kas brengt een energieneutrale teelt binnen bereik, met name voor potplanten- en bloementelers. De splitsing van het zonlicht door een daglichtinstallatie in de kas is het geheim daarachter. Direct zonlicht wordt weggevangen voor de productie van warmte en elektriciteit, terwijl het diffuse licht voor het gewas beschikbaar blijft.
    A model-based greenhouse design method
    Vanthoor, B.H.E. - \ 2011
    Wageningen University. Promotor(en): Eldert van Henten, co-promotor(en): Cecilia Stanghellini; Pieter de Visser. - [s.l.] : S.n. - ISBN 9789085859192 - 307
    kassen - glastuinbouw - constructie - ontwerp - materialen - bouwtechnologie - modellen - klimaatfactoren - dynamisch modelleren - greenhouses - greenhouse horticulture - construction - design - materials - construction technology - models - climatic factors - dynamic modeling
    Doel van dit proefschrift is het ontwikkelen van een methode die kasontwerpen genereert die geschikt zijn voor de locale klimaat en economische condities. Deze methode moet functioneren voor de verschillende condities die men wereldwijd tegen kan komen. De ontwerpmethode die ontwikkeld is maakt gebruik van computermodellen.
    Nokschermen voorkomen kouval (interview met o.a. Peter van Weel)
    Sleegers, J. ; Weel, P.A. van - \ 2011
    Vakblad voor de Bloemisterij 66 (2011)15. - ISSN 0042-2223 - p. 34 - 35.
    glastuinbouw - kassen - schermen - materialen - constructie - gebruikswaarde - greenhouse horticulture - greenhouses - blinds - materials - construction - use value
    Bedrijven die belichten onder een dicht scherm hebben vaak las van kouval. Nokschermen zijn dan een goede en goedkope oplossing. Er zijn verschillende materialen en constructies mogelijk.
    Do scale frames matter? Scale frame mismatches in the decision making process of a 'mega farm' in a small Dutch village
    Lieshout, M. van; Dewulf, A. ; Aarts, M.N.C. ; Termeer, C.J.A.M. - \ 2011
    Ecology and Society 16 (2011)1. - ISSN 1708-3087 - p. 38 - 38.
    resource-management - governance - construction - multilevel - conflict - systems
    Scale issues are an increasingly important feature of complex sustainability issues, but they are mostly taken for granted in policy processes. However, the scale at which a problem is defined as well as the scale at which it should be solved are potentially contentious issues. The framing of a problem as a local, regional, or global problem is not without consequences and influences processes of inclusion and exclusion. Little is known about the ways actors frame scales and the effect of different scale frames on decision making processes. This paper addresses the questions that different scale frames actors use and what the implications of scale frames are for policy processes. It does so by analyzing the scale frames deployed by different actors on the establishment of a so-called new mixed company or mega farm and the related decision making process in a Dutch municipality. We find that actors deploy different and conflicting scale frames, leading to scale frame mismatches. We conclude that scale frame mismatches play an important role in the stagnation of the decision making process
    Databases, scaling practices, and the globalization of biodiversity
    Turnhout, E. ; Boonman-Berson, S.H. - \ 2011
    Ecology and Society 16 (2011)1. - ISSN 1708-3087 - p. 35 - 35.
    environmental governance - politics - construction - perspective - multilevel
    Since the Convention on Biological Diversity in 1992, biodiversity has become an important topic for scientific research. Much of this research is focused on measuring and mapping the current state of biodiversity, in terms of which species are present at which places and in which abundance, and making extrapolations and future projections, that is, determining the trends. Biodiversity databases are crucial components of these activities because they store information about biodiversity and make it digitally available. Useful biodiversity databases require data that are reliable, standardized, and fit for up-scaling. This paper uses material from the EBONE-project (European Biodiversity Observation Network) to illustrate how biodiversity databases are constructed, how data are negotiated and scaled, and how biodiversity is globalized. The findings show a continuous interplay between scientific ideals related to objectivity and pragmatic considerations related to feasibility and data availability. Statistics was a crucial feature of the discussions. It also proved to be the main device in up-scaling the data. The material presented shows that biodiversity is approached in an abstract, quantitative, and technical way, disconnected from the species and habitats that make up biodiversity and the people involved in collecting the data. Globalizing biodiversity involves decontextualization and standardization. This paper argues that while this is important if the results of projects like EBONE are to be usable in different contexts, there is a risk involved as it may lead to the alienation from the organizations and volunteers who collect the data upon which these projects rely
    Towards a unified genetic map of diploid roses
    Spiller, M. ; Hibrand-Saint Oyant, L. ; Tsai, C. ; Byrne, D.H. ; Smulders, M.J.M. ; Foucher, A.L.J.L. ; Debener, T. - \ 2011
    Theoretical and Applied Genetics 122 (2011)3. - ISSN 0040-5752 - p. 489 - 500.
    marker-assisted selection - linkage maps - mapping populations - disease resistance - tetraploid roses - integrated map - aflp markers - construction - traits - genome
    We have constructed the first integrated consensus map (ICM) for rose, based on the information of four diploid populations and more than 1,000 initial markers. The single population maps are linked via 59 bridge markers, on average 8.4 per linkage group (LG). The integrated map comprises 597 markers, 206 of which are sequence-based, distributed over a length of 530 cM on seven LGs. By using a larger effective population size and therefore higher marker density, the marker order in the ICM is more reliable than in the single population maps. This is supported by a more even marker distribution and a decrease in gap sizes in the consensus map as compared to the single population maps. This unified map establishes a standard nomenclature for rose LGs, and presents the location of important ornamental traits, such as self-incompatibility, black spot resistance (Rdr1), scent production and recurrent blooming. In total, the consensus map includes locations for 10 phenotypic single loci, QTLs for 7 different traits and 51 ESTs or gene-based molecular markers. This consensus map combines for the first time the information for traits with high relevance for rose variety development. It will serve as a tool for selective breeding and marker assisted selection. It will benefit future efforts of the rose community to sequence the whole rose genome and will be useful for synteny studies in the Rosaceae family and especially in the section Rosoideae
    Genetic mapping in Lilium: mapping of major genes and quantitative trait loci for several ornamental traits and disease resistances
    Shahin, A. ; Arens, P.F.P. ; Heusden, S. van; Linden, C.G. van der; Kaauwen, M.P.W. van; Nadeem Khan, M. ; Schouten, H.J. ; Weg, W.E. van de; Visser, R.G.F. ; Tuyl, J.M. van - \ 2011
    Plant Breeding 130 (2011)3. - ISSN 0179-9541 - p. 372 - 382.
    diversity arrays technology - linkage map - zea-mays - segregation distortion - wild relatives - durum-wheat - markers - dart - construction - pollination
    Construction of genetic linkage maps for lily was achieved using two populations, LA and AA that share one parent ‘Connecticut King’. Three different molecular marker systems (AFLP™, DArT and NBS profiling) were used in generating linkage maps for ‘Connecticut King’. The LA and the AA populations consist of 20 and 21 linkage groups (LGs), respectively. Average density between markers was 3.9 cM for the LA and 5 cM for the AA population. Several horticultural traits were mapped for the first time in Lilium and showed to be single gene based. We propose to name these genes as LFCc for flower colour, lfs for flower spots, LSC for stem colour, lal for antherless phenotype and lfd for flower direction whereby upper and lower case names refer to dominant and recessive genes, respectively. Additionally, resistance to Lily mottle virus (LMoV) was mapped as a locus on LG AA10. For Fusarium resistance, the Kruskal–Wallis test identified six putative quantitative trait loci (QTL) in the AA population of which one QTL (explaining 25% of the variation in resistance) could be confirmed by interval mapping
    Disentangling scale approaches in governance research: comparing monocentric, multilevel, and adaptive governance
    Termeer, C.J.A.M. ; Dewulf, A. ; Lieshout, M. van - \ 2010
    Ecology and Society 15 (2010)4. - ISSN 1708-3087 - p. 29 - 29.
    social-ecological systems - resource regimes - water-resources - global change - size - construction - organization - perspective - management - government
    The question of how to govern the multiscale problems in today’s network society is an important topic in the fields of public administration, political sciences, and environmental sciences. How scales are defined, studied, and dealt with varies substantially within and across these fields. This paper aims to reduce the existing conceptual confusion regarding scales by disentangling three representative approaches that address both governance and scaling: monocentric governance, multilevel governance, and adaptive governance. It does so by analyzing the differences in (1) underlying views on governing, (2) assumptions about scales, (3) dominant problem definitions regarding scales, and (4) preferred responses for dealing with multiple scales. Finally, this paper identifies research opportunities within and across these approaches.
    Dak en gevelgroen
    Hop, M.E.C.M. - \ 2010
    daken - constructie - gebouwen - ontwerp - architectuur - vegetatie - soortenkeuze - groene daken - technische informatie - tuinarchitectuur - groene gevels - roofs - construction - buildings - design - architecture - vegetation - choice of species - green roofs - technical information - garden architecture - green walls
    Deze brochure geeft zoveel mogelijk informatie gebaseerd op harde cijfers uit onderzoek en ervaringen van professionals. De informatie is bestemd voor mensen die over dak- en gevelgroen communiceren, en daarvoor goede basisinformatie willen hebben. Bijvoorbeeld gemeenten, woningbouwverenigingen, architecten, bouwbedrijven en opdrachtgevers.De toepassing van dak- en gevelgroen is de afgelopen jaren in Nederland in een stroomversnelling gekomen. Steeds meer gemeenten geven er subsidie voor. Ook het onderzoek naar de effecten van dak- en gevelgroen kan steeds beter worden onderbouwen, waarom deze typen groen zo belangrijk zijn voor steden. Een ander onderwerp dat in deze brochure vrij uitvoerig wordt behandeld is welke beplanting het meest geschikt is voor dak- en gevelgroen. De keuze van de genoemde planten is gebaseerd op zoveel mogelijk relevante aspecten, zoals grootte, zontolerantie, waterbehoefte, inheems of exoot, schadelijkheid van de wortels, effect op luchtvervuiling, maar ook praktische punten als verkrijgbaarheid. Dit maakt de brochure ook voor boomkwekers, ontwerpers en aanlegbedrijven van dak- en gevelgroen interessant.
    Vooral aantal schermen en gebruik bepalend voor energiebesparing (interview met Jouke Campen en Feije de Zwart)
    Staalduinen, J. van; Campen, J.B. ; Zwart, H.F. de - \ 2010
    Onder Glas 7 (2010)5. - p. 62 - 63.
    kassen - thermische schermen - constructie - schermen - bouwmaterialen - isolatie (insulation) - standaardisering - methodologie - glastuinbouw - energiebesparing - greenhouses - thermal screens - construction - blinds - building materials - insulation - standardization - methodology - greenhouse horticulture - energy saving
    TNO en Wageningen UR hebben hun verschillende methodieken voor de bepaling van U-waarden geëvalueerd en vervangen door één nieuwe methode. Dit biedt zowel producenten als gebruikers meer duidelijkheid. Onderzoek naar hoogisolerende schermconfiguraties heeft uitgewezen dat een extra schermlaag meer bespaart dan het vervangen van bestaande schermen door doeken of folies met lagere U-waarden. Met een hoogtransparant scherm en actieve ontvochtiging met aangezogen buitenlucht, is overdag veel winst te boeken.
    A pipeline for high throughput detection and mapping of SNPs from EST databases
    Anithakumari, A.M. ; Tang, Jifeng ; Eck, H.J. van; Visser, R.G.F. ; Leunissen, J.A.M. ; Vosman, B. ; Linden, C.G. van der - \ 2010
    Molecular Breeding 26 (2010)1. - ISSN 1380-3743 - p. 65 - 75.
    single-nucleotide polymorphisms - map-based cloning - linkage maps - genome - markers - potato - discovery - construction - varieties - haplotype
    Single nucleotide polymorphisms (SNPs) represent the most abundant type of genetic variation that can be used as molecular markers. The SNPs that are hidden in sequence databases can be unlocked using bioinformatic tools. For efficient application of these SNPs, the sequence set should be error-free as much as possible, targeting single loci and suitable for the SNP scoring platform of choice. We have developed a pipeline to effectively mine SNPs from public EST databases with or without quality information using QualitySNP software, select reliable SNP and prepare the loci for analysis on the Illumina GoldenGate genotyping platform. The applicability of the pipeline was demonstrated using publicly available potato EST data, genotyping individuals from two diploid mapping populations and subsequently mapping the SNP markers (putative genes) in both populations. Over 7000 reliable SNPs were identified that met the criteria for genotyping on the GoldenGate platform. Of the 384 SNPs on the SNP array approximately 12% dropped out. For the two potato mapping populations 165 and 185 SNPs segregating SNP loci could be mapped on the respective genetic maps, illustrating the effectiveness of our pipeline for SNP selection and validation. Electronic supplementary material The online version of this article (doi:10.1007/s11032-009-9377-5) contains supplementary material, which is available to authorized users
    Microsatellite genotyping of apple (Malus × domestica Borkh.) genetic resources in the Netherlands: application in collection management and variety identification
    Treuren, R. van; Kemp, H. ; Ernsting, G. ; Jongejans, B. ; Houtman, H. ; Visser, L. - \ 2010
    Genetic Resources and Crop Evolution 57 (2010)6. - ISSN 0925-9864 - p. 853 - 865.
    appels - genenbanken - genotypen - genetische merkers - microsatellieten - genetische diversiteit - fenotypen - apples - gene banks - genotypes - genetic markers - microsatellites - genetic diversity - phenotypes - molecular characterization - ssr markers - construction - polymorphism - database - tomato - plants - dna
    A highly informative set of 16 microsatellite markers was used to fingerprint 695 apple accessions from eight Dutch collections. Among the total sample, 475 different genotypes were distinguished based on multi-locus microsatellite variation, revealing a potential redundancy within the total sample of 32%. The majority of redundancies were found between collections, rather than within collections. No single collection covered the total observed diversity well, as each collection consisted of about 50% of unique accessions. These findings reflected the fact that most collection holders focus on common Dutch varieties, as well as on region-specific diversity. Based on the diversity patterns observed, maintenance of genetic resources by a network of co-operating collection holders, rather than by collecting the total diversity in a single collection appears to be an efficient approach. Comparison of microsatellite and passport data showed that for many accessions the marker data did not provide support for the registered variety names. Verification of accessions showed that discrepancies between passport and molecular data were largely due to documentation and phenotypic determination errors. With the help of the marker data the varietal names of 45 accessions could be corrected. Microsatellite genotyping of apple appears to be an efficient tool in the management of collections and in variety identification. The development of a marker database was considered relevant as a reference instrument in variety identification and as a source of information about thus far unexplored diversity that could be of interest in the development of new apple varieties
    Development and evaluation of robust molecular markers linked to disease resistance in tomato for distinctness, uniformity and stabilty
    Arens, P.F.P. ; Mansilla, C. ; Deinum, D. ; Cavellini, L. ; Moretti, A. ; Rolland, S. ; Schoot, H. van der; Calvache, D. ; Ponz, F. ; Collonnier, C. ; Mathis, R. ; Smilde, D. ; Caranta, C. ; Vosman, B. - \ 2010
    Theoretical and Applied Genetics 120 (2010)3. - ISSN 0040-5752 - p. 655 - 664.
    nucleotide-binding - genes - dissection - varieties - construction - database - network - tm-2(2) - family - locus
    Molecular markers linked to phenotypically important traits are of great interest especially when traits are difficult and/or costly to be observed. In tomato where a strong focus on resistance breeding has led to the introgression of several resistance genes, resistance traits have become important characteristics in distinctness, uniformity and stability (DUS) testing for Plant Breeders Rights (PBR) applications. Evaluation of disease traits in biological assays is not always straightforward because assays are often influenced by environmental factors, and difficulties in scoring exist. In this study, we describe the development and/or evaluation of molecular marker assays for the Verticillium genes Ve1 and Ve2, the tomato mosaic virus Tm1 (linked marker), the tomato mosaic virus Tm2 and Tm2 2 genes, the Meloidogyne incognita Mi1-2 gene, the Fusarium I (linked marker) and I2 loci, which are obligatory traits in PBR testing. The marker assays were evaluated for their robustness in a ring test and then evaluated in a set of varieties. Although in general, results between biological assays and marker assays gave highly correlated results, marker assays showed an advantage over biological tests in that the results were clearer, i.e., homozygote/heterozygote presence of the resistance gene can be detected and heterogeneity in seed lots can be identified readily. Within the UPOV framework for granting of PBR, the markers have the potential to fulfil the requirements needed for implementation in DUS testing of candidate varieties and could complement or may be an alternative to the pathogenesis tests that are carried out at present.
    A strong effect of growth medium and organ type on the identification of QTLs for phytate and mineral concentrations in three Arabidopsis thaliana RIL populations
    Ghandilyan, A. ; Ilk, N. ; Hanhart, C.J. ; Mbengue, M. ; Barboza, L. ; Schat, H. ; Koornneef, M. ; El-Lithy, M.E.M. ; Vreugdenhil, D. ; Reymond, M. ; Aarts, M.G.M. - \ 2009
    Journal of Experimental Botany 60 (2009)5. - ISSN 0022-0957 - p. 1409 - 1425.
    quantitative trait loci - inbred line population - natural variation - erecta - seeds - construction - accumulation - efficiency - nutrition - ecotypes
    The regulation of mineral accumulation in plants is genetically complex, with several genetic loci involved in the control of one mineral and loci affecting the accumulation of different minerals. To investigate the role of growth medium and organ type on the genetics of mineral accumulation, two existing (LerxKond, LerxAn-1) and one new (LerxEri-1) Arabidopsis thaliana Recombinant Inbred Line populations were raised on soil and hydroponics as substrates. Seeds, roots, and/or rosettes were sampled for the determination of their Ca, Fe, K, Mg, Mn, P or Zn concentrations. For seeds only, the concentration of phytate (IP6), a strong chelator of seed minerals, was determined. Correlations between minerals/IP6, populations, growth conditions, and organs were determined and mineral/IP6 concentration data were used to identify quantitative trait loci (QTLs) for these traits. A striking difference was found between QTLs identified for soil-grown versus hydroponics-grown populations and between QTLs identified for different plant organs. Three common QTLs were identified for several populations, growth conditions, and organs, one of which corresponded to the ERECTA locus, variation of which has a strong effect on plant morphology
    Did the pile driving during the construction of the Offshore Wind Farm Egmond aan Zee, the Netherlands, impact porpoises?
    Leopold, M.F. ; Camphuysen, C.J. - \ 2009
    Texel : IMARES (Report / Wageningen IMARES C091/09) - 17
    windenergie - windmolens - geluidsproductie - geluidshinder - akoestische emissie - civiele techniek - constructie - pijlers - milieueffect - noordzee - nederland - offshore - onderwaterakoestiek - phocoenidae - wind power - windmills - sound production - noise pollution - acoustic emissions - civil engineering - construction - piles - environmental impact - north sea - netherlands - offshore - underwater acoustics - phocoenidae
    The Dutch consortium "NoordzeeWind" has built the first offshore wind farm in Dutch North Sea waters, known as "Offshore Wind farm Egmond aan Zee" (OWEZ) Part of the construction works consisted of driving 36 monopiles into the sea floor, during April-June 2006. The noise levels that attended this activity may have been detrimental to marine life forms. Cetaceans in particular are sensitive to very high noise levels and a possible impact on the most abundant cetacean living off the Dutch coast, the harbour porpoise was therefore studied. Direct observations were hard to conduct, given the low (summer) densities of porpoises around the construction site. Pathological observations on stranded specimen failed to produce clear results. Inner ears of freshly stranded porpoises were examined for possible damage, but before necropsies could be conducted the animals had been stored frozen and this had destroyed any visible signs of noise-induced damage to the inner ear. Thus, the spatiotemporal pattern of porpoise strandings was examined. Porpoises did not strand in higher numbers on the coastal stretch directly east of the construction site, or to the north-east of this location (downstream) compared to other parts of the country. Porpoises also did not strand in higher than expected numbers near the construction site, at the time of construction. It was therefore concluded that the construction did not lead to visibly increased mortality of harbour porpoises. In retrospect this might have been expected, given that densities of porpoises are normally very low in summer at the site, that the building process is noisy anyway, scaring porpoises off (to safe distances) before the actual pile driving commences. A ramp-up procedure and usage of a pinger further helped to ward off porpoises from the site, before full-power pile driving started. These factors combined (timing and high before-pile driving noise levels) made it very unlikely that porpoises got in harm’s way during the construction of OWEZ.
    Accessing information in working memory: Can the focus of attention grasp two elements at the same time?
    Oberauer, K. ; Bialkova, S.E. - \ 2009
    Journal of Experimental Psychology. General 138 (2009)1. - ISSN 0096-3445 - p. 64 - 87.
    short-term-memory - individual-differences - premise integration - task - capacity - comprehension - model - costs - representations - construction
    Processing information in working memory requires selective access to a subset of working-memory contents by a focus of attention. Complex cognition often requires joint access to 2 items in working memory. How does the focus select 2 items? Two experiments with an arithmetic task and 1 with a spatial task investigate time demands for successive operations that involve 2 digits or 2 spatial positions, respectively. When both items used in an operation have been used in the preceding operation, latencies are shortened. No such repetition benefit (arithmetic) or a much smaller benefit (spatial) was found when only 1 item was repeated. The results rule out serial access to the 2 items, parallel access by expanding the focus, and parallel access by splitting the focus. They support the notion that 2 items are accessed by chunking them, so that they fit a focus limited to 1 chunk. Keywords: attention, working memory, relations
    Ordering dominant markers in F2 populations
    Jansen, J. - \ 2009
    Euphytica 165 (2009)2. - ISSN 0014-2336 - p. 401 - 417.
    genetic-linkage maps - construction - likelihood
    Ordering dominant markers in F2 populations is considered a difficult problem. The difficulties arise from the fact that recombinations cannot be observed directly from the data. In general, the multi-point maximum likelihood would be the appropriate criterion for ordering markers. This criterion takes into account all available information present in marker data. However, calculation of multi-point maximum likelihoods is very time-demanding, especially if the number of markers is large. In this paper, ordering markers by minimising the number of recombinations between adjacent markers is used as a simple alternative to multi-point maximum likelihood. Contrary to multi-point maximum likelihood, this method does not involve any probability assumptions about the occurrence of recombination events. Simulated data indicate that the minimum number of recombinations between adjacent markers is approximately a linear function of the map length obtained by multi-point maximum likelihood. As a consequence, it will lead to more or less the same optimum marker orders. Optimisation of marker orders with regard to the number of recombinations between adjacent markers is carried out by a modified form of simulated annealing. The reliability of the resulting marker orders is studied by generating marker orders that are plausible with the data using a Metropolis algorithm
    The Potential Of High-Resolution BAC-FISH In Banana Breeding
    Capdeville, G. De; Souza, M.T. ; Szinay, D. ; Eugenio Cardamone Diniz, L. ; Wijnker, T.G. ; Swennen, R. ; Kema, G.H.J. ; Jong, J.H.S.G.M. de - \ 2009
    Euphytica 166 (2009)3. - ISSN 0014-2336 - p. 431 - 443.
    artificial chromosome library - in-situ hybridization - musa-acuminata - diploid bananas - genome structure - dna - hybrids - gene - construction - balbisiana
    Abstract The genetic complexity in the genus Musa has been subject of study in many breeding programs worldwide. Parthenocarpy, female sterility, polyploidy in different cultivars and limited amount of genetic and genomic information make the production of new banana cultivars difficult and time consuming. In addition, it is known that part of the cultivars and related wild species in the genus contain numerous chromosomal rearrangements. In order to produce new cultivars more effectively breeders must better understand the genetic differences of the potential crossing parents for introgression hybridization, but extensive genetic information is lacking. As an alternative to achieve information on genetic collinearity we make use of modern chromosome map technology known as high-resolution fluorescent in situ hybridization (FISH). This article presents the technical aspects and applications of such a technology in Musa species. The technique deals with BAC clone positioning on pachytene chromosomes of Calcutta 4 (Musa acuminata ssp. burmanicoides, A genome group, section Eumusa) and M. velutina (section Rodochlamys). Pollen mother cells digestion with pectolytic enzymes and maceration with acetic acid were optimized for making cell spread preparations appropriate for FISH. As an example of this approach we chose BAC clones that contain markers to known resistance genes and hybridize them for establishing their relative positions on the two species. Technical challenges for adapting existing protocols to the banana cells are presented. We also discuss how this technique can be instrumental for validating collinearity between potential crossing parents and how the method can be helpful in future mapping initiatives, and how this method allows identification of chromosomal rearrangements between related Musa species and cultivars
    Genetic mapping and transcription analyses of resistance gene loci in potato using NBS profiling
    Brugmans, B.W. ; Wouters, D.C.A.E. ; Os, H. van; Hutten, R.C.B. ; Linden, C.G. van der; Visser, R.G.F. ; Eck, H.J. van; Vossen, E.A.G. van der - \ 2008
    Theoretical and Applied Genetics 117 (2008)8. - ISSN 0040-5752 - p. 1379 - 1388.
    disease-resistance - confers resistance - map - tomato - genome - construction - arabidopsis - proteins - sequence - analogs
    NBS profiling is a method for the identification of resistance gene analog (RGA) derived fragments. Here we report the use of NBS profiling for the genome wide mapping of RGA loci in potato. NBS profiling analyses on a minimal set of F1 genotypes of the diploid mapping population previously used to generate the ultra dense (UHD) genetic map of potato, allowed us to efficiently map polymorphic RGA fragments relative to 10,000 existing AFLP markers. In total, 34 RGA loci were mapped, of which only 13 contained RGA sequences homologous to RGAs genetically positioned at approximately similar positions in potato or tomato. The remaining RGA loci mapped either at approximate chromosomal regions previously shown to contain RGAs in potato or tomato without sharing homology to these RGAs, or mapped at positions not yet identified as RGA-containing regions. In addition to markers representing RGAs with unknown functions, segregating markers were detected that were closely linked to four functional R genes that segregate in the UHD mapping population. To explore the potential of NBS profiling in RGA transcription analyses, RNA isolated from different tissues was used as template for NBS profiling. Of all the fragments amplified approximately 15% showed putative intensity or absent/present differences between different tissues suggesting putative tissue specific RGA or R gene transcription. Putative absent/present differences between individuals were also found. In addition to being a powerful tool for generating candidate gene markers linked to R gene loci, NBS profiling, when applied to cDNA, can be instrumental in identifying those members of an R gene cluster that are transcribed, and thus putatively functional.
    Marker-assisted optimization of an expert-based strategy for the acquisition of modern lettuce varieties to improve a genebank collection
    Treuren, R. van; Hintum, T.J.L. van; Wiel, C.C.M. van de - \ 2008
    Genetic Resources and Crop Evolution 55 (2008)2. - ISSN 0925-9864 - p. 319 - 330.
    genetic-variation - bremia-lactucae - accessions - construction - resistance - database - tomato - aflps - rapd
    To regularly improve the composition of the lettuce collection of the Centre for Genetic Resources, the Netherlands (CGN) with modern varieties, feedback from crop experts is used to select approximately 10% of the new material for incorporation in the collection. In the present study, assessments of six experts were compared to microsatellite data of 414 new varieties and 1408 existing accessions. Based on the microsatellite data, the extent to which the genetic diversity of the collection would be enriched (added value) was calculated for specific sets of new varieties. When individual assessments of experts were evaluated, the total added value of expert-based selections was not significantly higher compared to randomly chosen groups, except for a single expert. Unfamiliarity with new varieties was shown to be a crucial factor in the assessment of crop experts. According to the current acquisition protocol that seeks for consensus among experts, varieties are selected based on recommendations from at least three experts. This protocol also did not perform better than randomly chosen groups of new varieties. However, significantly better results were obtained with alternative protocols. It was concluded that breeding value was a more decisive criterion in the current acquisition protocol than maximal extension of the genetic diversity within the collection. A modified protocol addressing both commercial and diversity aspects was suggested in order to meet the demands of plant breeders as well as conservationists
    Elkas levert gewas én stroom : kas met zonnecellen geopend in Wageningen
    Vegter, B. ; Sonneveld, P.J. - \ 2008
    Vakblad voor de Bloemisterij 63 (2008)26. - ISSN 0042-2223 - p. 36 - 37.
    kassen - elektriciteitsgeneratoren - zonne-energie - elektriciteit - bouwtechnologie - constructie - glastuinbouw - kastechniek - greenhouses - electricity generators - solar energy - electricity - construction technology - construction - greenhouse horticulture - greenhouse technology
    WUR Glastuinbouw heeft de Elkas gebouwd, die warmte en stroom kan leveren. Het gebogen glas kaatst het NIR-licht terug op zonnecellen, die elektriciteit opwekken. Het PAR-licht wordt doorgelaten voor de gewasgroei
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