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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    Fotoperiodisch stuurlicht : verkenning van de mogelijkheden voor toepassing van fotoperiodisch stuurlicht om de groei te stimuleren
    Boer-Tersteeg, P.M. de; Marcelis, L.F.M. - \ 2009
    Bleiswijk : Wageningen UR Glastuinbouw (Rapport / Wageningen UR Glastuinbouw 283) - 30
    teelt onder bescherming - lichtregiem - lichtrelaties - fotoperiodiciteit - lichtsterkte - plantenontwikkeling - landbouwkundig onderzoek - glastuinbouw - protected cultivation - light regime - light relations - photoperiodism - light intensity - plant development - agricultural research - greenhouse horticulture
    In deze desk-studie is door literatuurstudie en gesprekken met onderzoekers met ervaring op dit terrein en enkele telers een inventarisatie gemaakt van achtergronden en mogelijkheden van fotoperiodische belichting om groei te stimuleren in de praktijk
    WUR-onderzoek naar belichting in roos: Licht het hele etmaal goed benut
    Medema, Dennis ; Dieleman, J.A. - \ 2007
    Vakblad voor de Bloemisterij 2007 (2007)43. - ISSN 0042-2223 - p. 42 - 43.
    kassen - belichting - kunstlicht - plantenontwikkeling - fotosynthese - lichtrelaties - fotoperiodiciteit - glastuinbouw - greenhouses - illumination - artificial light - plant development - photosynthesis - light relations - photoperiodism - greenhouse horticulture
    Rozen kunnen vrijwel het hele etmaal omgaan met groeilicht. Dat blijkt uit onderzoek van Wageningen UR Glastuinbouw. Vanuit de plant gezien is er dus geen reden om de belichting uit te schakelen. Voorwaarde is dat het niet te warm en te droog wordt in de kas, want dan loopt de fotosynthese terug
    Fasegestuurde rozenteelt: Effecten van temperatuur, licht, CO², EC en luchtvochtigheid op de lengte en synchronie van drie onderscheiden ontwikkelingsfases
    Eveleens-Clark, B.A. ; García, Nieves ; Kouwenhoven, D. ; Wurff, A.A.M. van der; Telgen, H.J. van - \ 2004
    Naaldwijk : Praktijkonderzoek Plant & Omgeving B.V. BU Glastuinbouw (Rapporten PPO Glastuinbouw ) - 33
    rosaceae - rosa - rozen - snijbloemen - temperatuur - fotoperiodiciteit - kooldioxide - vochtigheid - glastuinbouw - gewassen, groeifasen - nederland - rosaceae - rosa - roses - cut flowers - temperature - photoperiodism - carbon dioxide - humidity - greenhouse horticulture - crop growth stage - netherlands
    Voor u ligt het verslag van de resultaten van drie projecten rond het thema faseafhankelijke rozenteelt. Het eerste project liep van maart 2002 tot 30 juni 2003 (PPO-project 41300062) en werd verlengd van juni 2003 tot maart 2004 (PPO-project 41304019) en van maart 2004 tot en met december 2004. In de periode maart 2002 tot en met oktober 2004 zijn in totaal 23 groeicycli of sneeën van een rozengewas van de cultivar ‘First Red’ in klimaatkassen nauwkeurig bestudeerd en zowel als afzonderlijke proef als geheel geanalyseerd.
    Optimaal gebruik van natuurlijk licht in de glastuinbouw
    Hemming, S. ; Waaijenberg, D. ; Bot, G. ; Sonneveld, P. ; Zwart, F. de; Dueck, T.A. ; Dijk, C.J. van; Dieleman, J.A. ; Marissen, N. ; Rijssel, E. van; Houter, G. - \ 2004
    Wageningen : Agrotechnology & Food Innovations (Rapport / Agrotechnology & Food Innovations nr. 100) - ISBN 9789067547673 - 155
    licht - natuurlijk licht - fotoperiode - fotoperiodiciteit - fotosynthese - kasgewassen - isolatiematerialen - energiebehoud - kassen - glastuinbouw - light - natural light - photoperiod - photoperiodism - photosynthesis - greenhouse crops - insulating materials - energy conservation - greenhouses - greenhouse horticulture
    Natuurlijk licht is een van de belangrijkste factoren met betrekking tot de groei en ontwikkeling van planten. Door het proces van fotosynthese maakt de plant bouwstoffen aan voor de groei vanuit de onderdelen licht, water en CO2. In dit rapport wordt enerzijds de lichtbehoefte van gewassen besproken en anderzijds de technische mogelijkheden van omhullingsmaterialen en schermen om het licht in de kas te beïnvloeden. Het rapport beperkt zich tot het natuurlijke licht en laat dus het kunstlicht hier buiten beschouwing. Na een inleiding in hoofdstuk 1 volgt in hoofdstuk 2 de beschrijving wat licht en globale straling is, wat de hoeveelheid straling is in verschillende seizoenen, uit welke lichtkleuren de globale straling is samengesteld en hoe de daglengte in Nederland varieert. In hoofdstuk 3 is beschreven wat de lichtbehoefte van planten voor de fotosynthese en de morfogenese is. Tevens is de lichtbehoefte van gewassen tijdens de opkweek van het uitgangsmateriaal en tijdens de productiefase onderzocht. Per gewasgroep (vruchtgroenten, bladgroenten, snijbloemen, potplanten) wordt aangegeven welke lichtintensiteit en welk spectrum nodig is, om een optimale gewasproductie te realiseren. In hoofdstuk 4 wordt geïnventariseerd, welke kasomhullings- en schermmaterialen er zijn, welke optische eigenschappen relevant zijn om natuurlijk licht in de kas door te laten dringen en welke technische mogelijkheden er zijn om deze materiaaleigenschappen aan te passen. In dit hoofdstuk wordt gekeken hoe een bepaalde lichtbehoefte voor een gewasgroep gerealiseerd of geoptimaliseerd zou kunnen worden en wat daarvan de gevolgen voor het gewas zijn. Aangezien natuurlijk licht tevens invloed heeft op de warmtebalans in een kas wordt ook het effect van de verschillende lichtbestanddelen op de energiehuishouding van de kas besproken. De kernresultaten zijn in hoofdstuk 5, de synthese samengevat, onderverdeeld naar de behoeften van gewasgroepen.
    Onderzoek lost stekprobleem in bioteelt op
    Derkx, M.P.M. - \ 2003
    De Boomkwekerij 16 (2003)15. - ISSN 0923-2443 - p. 8 - 9.
    houtachtige planten als sierplanten - vegetatieve vermeerdering - stekken - biologische landbouw - fotoperiode - fotoperiodiciteit - plantengroeiregulatoren - azospirillum - ornamental woody plants - vegetative propagation - cuttings - plant growth regulators - azospirillum - organic farming - photoperiod - photoperiodism
    Bij het biologisch vermeerderen van houtige gewassen worden geen groeiregulatoren gebruikt. Alternatieve methoden om wortelvorming te bevorderen zijn etioleren (moerplanten een aantal weken in het donker plaatsen vòòr het nemen van stekken) en de stekken behandelen met biologische stekpoeder. Gegevens in bijgaande figuren: 1) Bewortelingspercentages van top- en lidstekken van Syringa vulgaris; 2) Aantal wortels per stek van Syringa vulgaris; 3) Bewortelingspercentages van twee klonen van Acer platanoides; 4) Aantal wortels per stek van Acer platanoides. De stekken zijn afkomstig van moerplanten die in het donker hebben gestaan gevolgd door een korte-dagbehandeling, of van moerplanten die onder natuurlijke daglengte hebben gestaan.
    Photomorphogenesis
    Kendrick, R.E. ; Weller, J.L. - \ 2003
    In: Encyclopedia of Applied Plant Sciences / Thomas, B., Murphy, D.J., Murray, B.G., Elsevier/Academic Press - ISBN 9780122270505 - p. 1069 - 1076.
    fotoperiodiciteit - fototropie - fotoreceptoren - lichtregiem - fytochroom - zaadkieming - photoperiodism - phototropism - photoreceptors - light regime - phytochrome - seed germination
    Invloed lichtsom en CO2 op groei en ontwikkeling van Alstroemeria
    Noort, F. van - \ 2002
    Aalsmeer : Praktijkonderzoek Plant & Omgeving, Sector Glastuinbouw - 32
    alstroemeria - snijbloemen - fotoperiodiciteit - plantenfysiologie - plantenontwikkeling - gewasopbrengst - alstroemeria - cut flowers - photoperiodism - plant physiology - plant development - crop yield
    De invloed van de lichtsom per dag op de groei en ontwikkeling onder langedag-omstandigheden bij alstroemeria : vergelijking tussen twee daglengtes in vaste combinatie met de lichtintensiteit
    Nijssen, H. ; Smal, P. - \ 2001
    Aalsmeer : Proefstation voor Bloemisterij en Glasgroente, Vestiging Aalsmeer (Rapport / Proefstation voor Bloemisterij en Glasgroente 336) - 13
    alstroemeria - fotoperiodiciteit - plantenfysiologie - gewasopbrengst - plantenontwikkeling - snijbloemen - alstroemeria - photoperiodism - plant physiology - crop yield - plant development - cut flowers
    Bloeisturing begonia
    Verberkt, H. - \ 2000
    Aalsmeer etc. : Proefstation voor Bloemisterij en Glasgroente (Rapport / Proefstation voor Bloemisterij en Glasgroente 175) - 96
    begonia - bloei - fenologie - bloeidatum - bloembeginsels - lichtrelaties - fotoperiodiciteit - fotoperiode - temperatuur - begonia - flowering - phenology - flowering date - flower primordia - light relations - photoperiodism - photoperiod - temperature
    Begonia elatior is een kwantitatieve korte dag (KD) -plant. Dit betekent dat de bloeiïnductie en -aanleg bevorderd wordt indien de daglengte korter is dan de kritieke daglengte (12 uur). De planten kunnen echter ook in bloei komen wanneer andere omstandigheden, zoals plantleeftijd, temperatuur en lichthoeveelheid, gunstig zijn. Veelal spelen twee of meer factoren gelijktijdig een rol. Daarnaast geven rassen verschillen in bloeirespons. De afgelopen jaren zijn er in de praktijk problemen met ongewenste bloei in de moerplanten en stek geconstateerd. De vermeerdering van Begonia vindt hoofdzakelijk plaats via scheutstek. Bij scheutstekmoerplanten is het van belang dat de moerplanten en daarmee de stekken vegetatief blijven. De productie aan stekken van de moerplanten neemt hierdoor toe en de stekken krijgen na de beworteling eerst de kans om vegetatief uit te groeien. Indien een scheut echter reeds geïnduceerd is worden bloemen geproduceerd die ten koste gaan van de groei en de zijscheutontwikkeling. Reeds geïnduceerd stek ( = bloemstek) mag niet worden verkocht. In een aantal gevallen is bij de verkoop van het stek (nog) niet zichtbaar dat de stekken reeds geïnduceerd zijn. Op de teeltbedrijven treedt dan te vroeg bloei op. Dit geeft enerzijds extra arbeid om deze bloemen te verwijderen en anderzijds gaat dit ten koste van de groei, scheutvorming en bloeigelijkheid van een partij. Door de toenemende mechanisatie op de teeltbedrijven en de wensen van de handel om een van tevoren gedefinieerd product op een vooraf vastgesteld tijdstip af te nemen, neemt de vraag naar sturing en gelijkheid in bloei op de teeltbedrijven toe. In het begin van de teelt moet voorkomen worden dat te vroege bloei optreedt. Later in de teelt is het van belang, in verband met de arbeid en planning, dat de planten op het gewenste tijdstip zo gelijk mogelijk in bloei komen met voldoende bloemen en knoppen. De sturing van bloei richt zich dus afhankelijk van de teeltfase op een verschillend doel: • Gedurende de teelt van moerplanten en stekken moet bloei voorkomen worden. Dit leidt anders tot een geringe stekproductie en tot bloemstek. • In het begin van de productieteelt moet voorkomen worden dat te vroeg bloei optreedt. Dit geeft anders extra arbeid om deze bloemen te verwijderen en het gaat ten koste van de groei, scheutvorming en bloeigelijkheid van een partij. • Later in de productieteelt is, in verband met arbeid en planning, het van belang dat de planten op het gewenste tijdstip zo gelijk mogelijk in bloei komen met voldoende bloemen en knoppen. Hiertoe is kennis over de mogelijkheden van sturing van de bloei, op zowel de vermeerderingsbedrijven als de teeltbedrijven, noodzakelijk.
    A genetic and molecular analysis of two genes involved in flowering initiation of Arabidopsis = [Een genetische en moleculaire analyse van twee genen die betrokken zijn bij de bloei initiatie van Arabidopsis]
    Soppe, W.J.J. - \ 2000
    Agricultural University. Promotor(en): M. Koornneef. - S.l. : S.n. - ISBN 9789058082893 - 120
    arabidopsis - arabidopsis thaliana - genetische analyse - genen - genexpressie - biotechnologie - bloei - fotoperiodiciteit - circadiaan ritme - moleculaire genetica - mutanten - genomen - arabidopsis - arabidopsis thaliana - genetic analysis - genes - gene expression - biotechnology - flowering - photoperiodism - circadian rhythm - molecular genetics - mutants - genomes

    The transition from the vegetative to the reproductive phase (flowering initiation) in plants has a complex regulation which is affected by environmental and internal plant factors. The understanding of this process is not only of fundamental interest but could also lead to practical applications. The research into flowering initiation has a long history. The initial emphasis on physiological and biochemical studies led to the identification of different factors that influence flowering time. During the sixties, a genetic approach was initiated in different plant species. In Arabidopsis several late flowering mutants were isolated and genetically and physiologically characterised which revealed a complex regulation of flowering time by different pathways. These are the photoperiodic promotion pathway which promotes flowering under long day light conditions, the vernalisation promotion pathway which promotes flowering by low temperatures and the autonomous promotion pathway which promotes flowering independent of the environment. Due to its favourable genetic and molecular features, research on flowering initiation became focussed on Arabidopsis. Since the beginning of the nineties, several of the genes involved in the different pathways have been cloned, providing more information about the function of these genes in the cell and their relations with each other. Despite this increasing amount of information, the picture is still far from complete.

    The aim of the work presented in this thesis is to increase our knowledge of flowering time regulation. It focussed on the genetic and molecular characterisation of the semi-dominant mutant fwa , which flowers late under long day light conditions and has been proposed to be part of the photoperiodic promotion pathway. One approach sought to identify additional genes that affect flowering by mutagenesis of the fwa mutant. In addition to three different intragenic revertants of fwa , this screen yielded a novel early flowering mutant.

    This mutant was named early flowering in short days ( efs ). Its phenotypic characterisation has shown that the main role of the wild-type EFS gene is to delay flowering in plants that have entered the adult vegetative phase, which is considered to be the phase where plants are able to respond to environmental signals in order to flower. Consistent with this, efs mutant plants do not show an early flowering phenotype when grown under environmental conditions that lead to a shortened adult vegetative phase such as long days and vernalisation. To learn more about the role of EFS in relation to other genes involved in flowering initiation, double mutants were isolated. Their characterisation showed that efs is involved in the autonomous promotion pathway. This result, together with the lack of a vernalisation response, suggests that EFS is likely to represent a new element acting at a point close to the convergence of signals from the autonomous promotion pathway and the vernalisation promotion pathway.

    The main topic of this thesis concerns the map based cloning of the FWA gene. By using plants which have a cross-over between FWA and surrounding markers, the FWA locus could be located in a region of about 60 Kb. Plant transformation experiments with cosmids spanning this region showed that the gene is located in the overlap of two cosmids. This overlap contained only one complete gene that encodes a homeodomain containing transcription factor. The altered expression of this gene in fwa mutants together with DNA mutations in the intragenic revertants of fwa-1 further proved that this gene is FWA .

    Analysis of FWA revealed several interesting characteristics. Surprisingly, the mutant and wild-type alleles had an identical DNA sequence in the FWA region, excluding DNA mutations in the gene as a cause for the mutant phenotype. Furthermore, two direct repeated sequences were found in the 5' genomic region of FWA . In wild-type plants these repeats were heavily methylated, whereas they were completely un-methylated in the mutant alleles. In contrast to fwa mutant plants, which showed a high expression of FWA at all developmental stages, wild-type plants showed only a low expression of FWA in siliques and germinating seeds. Taken together, these findings suggest that loss of methylation of the FWA repeats in the fwa mutant causes a high level of expression of the gene, leading to a late flowering phenotype. A similar correlation of late flowering, FWA overexpression and hypomethylation of FWA repeats was found in late flowering plants which were derived from the ddm1 hypomethylation mutant. The late flowering phenotype of these plants had previously been mapped to the FWA region. Nevertheless, the correlation between hypomethylation of the FWA repeats and FWA expression was not found in germinating seeds of wild-type plants which showed expression of FWA but methylation of the repeats. Although this expression might come from residual mRNA produced earlier in developing seeds, it is possible that methylation of the repeats does not always prevent expression of FWA . Perhaps a different epigenetic mechanism early in development can induce expression of methylated genes.

    The correlation of FWA expression with late flowering indicates that FWA is a repressor of flowering. Earlier studies had already shown that FWA does not only play a role in the initiation of flowering but also in flower meristems. However, the FWA transcript was not detected in flower buds or flowers and therefore, FWA might only affect this process when highly expressed in the fwa mutant. Possibly, FWA has no function in flowering initiation of wild-type. It might participate in a seed-specific process, as suggested by its expression in seeds. However, the lack of an obvious phenotype suggests that this role is minor or redundant with other genes.

    The cloning of FWA revealed that the absence of methylation in the repeating sequences in the 5' region of the FWA gene leads to an enhanced expression in the fwa mutant. However, it did not become clear whether this correlation is direct or indirect. Also the importance of the methylation in wild-type plants is still unclear. It is possible that it has a role in the expression of the gene under specific environmental conditions.

    The results discussed in this thesis have contributed to the existing knowledge of flowering initiation by the isolation of a mutant at a novel locus and the cloning of a previously known gene which are both involved in this process. In addition, the results suggest a possible role for DNA methylation in gene regulation of Arabidopsis.

    Effect daglengte, temperatuur bloemknopvorming in Pieris-stek (project 1006)
    Ruesink, J.B. - \ 1998
    Boskoop : Boomteeltpraktijkonderzoek (Rapport / Boomteeltpraktijkonderzoek 52) - 27
    plantenfysiologie - plantenontwikkeling - bloemen - bloei - plantenvermeerdering - stekken - licht - fotoperiode - fotoperiodiciteit - schaduw - temperatuur - warmte - ericaceae - rapporten - potplanten - pieris japonica - binnen kweken (van planten) - plant physiology - plant development - flowers - flowering - propagation - cuttings - light - photoperiod - photoperiodism - shade - temperature - heat - ericaceae - reports - pot plants - pieris japonica - indoor culture
    Matching crops and environments : quantifying photothermal influences on reproductive development in bambara groundnut (Vigna subterranea (L.) Verdc.)
    Brink, M. - \ 1998
    Agricultural University. Promotor(en): R. Rabbinge; M. Wessel; E. Westphal. - S.l. : Brink - ISBN 9789054858751 - 161
    peulvruchten - groei - gewassen - vruchtdragend - vruchtzetten - licht - fotoperiode - fotoperiodiciteit - schaduw - temperatuur - warmte - computersimulatie - simulatie - simulatiemodellen - fenologie - planten - vigna subterranea - grain legumes - growth - crops - fruiting - fruit set - light - photoperiod - photoperiodism - shade - temperature - heat - computer simulation - simulation - simulation models - phenology - plants - vigna subterranea

    The extent to which crops are adapted to specific environments greatly depends on how their development is affected by climatic factors. Development in bambara groundnut ( Vigna subterranea (L.) Verdc.) is known to be influenced by temperature and photoperiod. The objective of this study was to quantify the influence of these factors on reproductive development in selections from different origins.

    Models relating development rates to photoperiod and temperature with linear equations were made for different bambara groundnut selections on the basis of research in semi-controlled environments. The photoperiod and temperature responses could be explained very well by the photothermal conditions in the regions where the selections were obtained. Validation of the models with the results of glasshouse and field experiments showed good to reasonable agreement between observed and predicted times to flowering and podding.

    It is shown that the average photoperiod between flowering and podding determines the rate from flowering to podding, and that a gradual increase or decrease in photoperiod does not affect that rate. This means that photothermal models intended to predict bambara groundnut development in field situations with fluctuating photoperiods can be based on studies with constant photoperiods. It is also shown that growth and development in bambara groundnut are largely independent and that there are no strong direct photoperiod effects on dry matter partitioning.

    The usefulness of photothermal development models for identifying suitable selections for different locations and sowing dates is demonstrated in a simulation study for Botswana. It is concluded that the influence of photoperiod and temperature on bambara groundnut development can be quantified through descriptive linear models, using data from semi-controlled environment experiments with constant temperatures and photoperiods. These quantitative models, either on their own or incorporated into a crop growth model, can be useful instruments for matching bambara groundnut genotypes and specific environments.

    Modelling interactions in grass-clover mixtures
    Nassiri Mahallati, M. - \ 1998
    Agricultural University. Promotor(en): L. 't Mannetje; A. Elgersma; E.A. Lantinga. - S.l. : Mahallati - ISBN 9789054858201 - 165
    graslanden - lolium - trifolium repens - stikstof - biologische mededinging - concurrentie tussen planten - plantenecologie - licht - fotoperiode - fotoperiodiciteit - schaduw - fotosynthese - computersimulatie - simulatie - simulatiemodellen - lolium perenne - grasslands - lolium - trifolium repens - nitrogen - biological competition - plant competition - plant ecology - light - photoperiod - photoperiodism - shade - photosynthesis - computer simulation - simulation - simulation models - lolium perenne

    The study described in this thesis focuses on a quantitative understanding of the complex interactions in binary mixtures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) under cutting. The first part of the study describes the dynamics of growth, production and the structural characteristics of contrasting grass and clover cultivars under field conditions. This basic information is used in the second part to quantify light absorption, C0 2 assimilation, radiation use efficiency (RUE) and light competition of the species using a modelling approach.

    Both species showed a seasonal pattern in growth of the dry matter (DM) and leaf area index (LAI) during the season so that the grass-dominated swards during spring shifted to clover dominance in summer. Without N fertilisation (-N), this seasonality was mainly controlled by the weather conditions. However, in fertilised mixtures (+N) grass was the dominant component of the mixture during the whole season and clover growth was always limited by light. The competitive ability and persistence of clover were determined by the structural characteristics of the cultivars. In the -N swards, both large and small-leaved clover cultivars had a higher proportion of their leaf area at the top canopy layers than their companion grass. In the +N mixtures, this was observed only in largeleaved clover, whereas the small-leaved cultivar was strongly overtopped. The difference between cultivars; was mainly due to the pattern of allocation of the DM into the supporting tissues.

    Experimental results showed two sources of vertical heterogeneity within the mixed grass-clover canopies: different patterns of LAI distribution and leaf dispersion. The validity of the canopy light partitioning model was considerably improved by introducing these sources of variation into the model. Using this model the RUE of species was calculated for different regrowth periods. Grass and clover had a different RUE in mixture and monoculture, but overall RUE was higher in grass, particularly in spring. The variation in the DM yield of grass under different treatments was due to changes in RUE and absorbed radiation. However, in clover these differences were mainly due to the amount of absorbed radiation. Quantification of light competition showed that in spring grass was the strongest competitor. In summer, the competitive ability of clover was related to N level and clover cultivar. Without N, both large and small-leaved clover were better competitors than grass. However, in the +N swards only the large-leaved clover had the same competitive ability as its companion grass. In both species a leaf N profile developed during regrowth, parallel to the light profile within the canopy. The effect of the observed compared to a uniform leaf N profile on canopy C02 assimilation of species was low, but it was different between mixtures and monocultures.

    It was concluded that the effect of canopy structure on productivity of species was more important than their assimilatory characteristics. The persistence of white clover under cutting may be improved by choosing cultivars with a higher competitive ability, based on canopy structure.

    DIF in relatie tot licht- en temperatuurniveau : onderzoek naar alternatieve groeiregulatoren bij perkplanten
    Vogelezang, J. - \ 1997
    Aalsmeer : Proefstation voor Bloemisterij en Glasgroente (Rapport / Proefstation voor Bloemisterij en Glasgroente 98) - 19
    tuinen - sierplanten - kunstlicht - verlichting - groeistadia - gewassen, groeifasen - licht - fotoperiode - fotoperiodiciteit - schaduw - temperatuur - warmte - rapporten - gardens - ornamental plants - artificial light - lighting - growth stages - crop growth stage - light - photoperiod - photoperiodism - shade - temperature - heat - reports
    Zomerklimaat cyclamen
    Verberkt, H. - \ 1997
    Aalsmeer : Proefstation voor Bloemisterij en Glasgroente (Rapport / Proefstation voor Bloemisterij en Glasgroente 79) - 47
    potplanten - kassen - klimaat - licht - fotoperiode - fotoperiodiciteit - schaduw - irrigatiewater-toedieningsschema - cyclamen - binnen kweken (van planten) - pot plants - greenhouses - climate - light - photoperiod - photoperiodism - shade - irrigation scheduling - cyclamen - indoor culture
    Sturing van de bloemontwikkeling van aster door daglengte
    Durieux, A. ; Blacquiere, T. - \ 1997
    Aalsmeer : Proefstation voor Bloemisterij en Glasgroente (Rapport / Proefstation voor Bloemisterij en Glasgroente 109) - 57
    licht - fotoperiode - fotoperiodiciteit - schaduw - plantenfysiologie - plantenontwikkeling - bloemen - bloei - sierplanten - aster - light - photoperiod - photoperiodism - shade - plant physiology - plant development - flowers - flowering - ornamental plants - aster
    Regulation of photosynthesis and energy dissipation in triazine-resistant and susceptible Chenopodium album
    Curwiel, V.B. - \ 1997
    Agricultural University. Promotor(en): W.J. Vredenberg; J.J.S. van Rensen. - S.l. : Curwiel - ISBN 9789054856924 - 107
    fotosynthese - chenopodiaceae - licht - fotoperiodiciteit - cellen - voeding - metabolisme - triazinen - gewasbescherming - resistentie tegen pesticiden - celmetabolisme - celinteracties - photosynthesis - chenopodiaceae - light - photoperiodism - cells - nutrition - metabolism - triazines - plant protection - pesticide resistance - cell metabolism - cell interactions

    As a consequence of the intensive use of herbicides during crop growth, many herbicideresistant biotypes have evolved. One of the first examples is the resistance of Chenopodium album against triazine-type herbicides. About ten years after this discovery, it was observed that triazine-resistant plants (R) have a lower rate of electron flow at the acceptor side of photosystem II. Later, the chloroplasts of the resistant biotype were described as having shadetype characteristics. In addition, the R biotype was found to have an altered lipid composition of the thylakoid membrane, to be more sensitive to high temperature and the thylakoid membrane has a low affinity for bicarbonate. In the presence of high irradiance, R is retarded in growth and development compared to the susceptible (S) biotype and has a higher sensitivity to photoinhibition (this thesis). The goal of this work was to contribute to a better understanding of the mechanistic relationship between light stress and photosynthetic yield, i.e. biomass production.

    In chapter 2 the effect of photoinhibition on electron transport and photophosphorylation in isolated chloroplasts is described. This research proved that photoinhibition causes a gradual uncoupling between electron transport and phosphorylation. This indicates that photoinhibition causes a proton leakiness of the thylakoid membrane. An important observation was that in vitro the two biotypes do not differ from each other in their sensitivity towards photoinhibition.

    Because R and S do not differ much in their sensitivity to photoinhibition in vitro, research was performed for the in vivo situation with intact leaves (Chapter 3). When plants have been grown at low light irradiance, little or no differences in dry matter productions appear to exist between the two biotypes. However, growth at high light irradiance causes a significantly lower production of the resistant biotype. Fluoresence studies indicated that the lower productivity of the resistant plants is caused by a higher sensitivity to photoinhibition. The less significant differences in vitro in comparison to the in vivo situation are probably caused by the loss or lower activity of photoprotective mechanisms during the isolation of chloroplasts.

    Further research into these protective mechanisms (Chapter 4) revealed that R shows more light-induced zeaxanthin formation and a larger change in light scattering than S, especially when grown at high irradiance. The difference in level of non-photochemical quenching (qN) is more pronounced at low light irradiance. Photorespiration acts as an energy dissipative mechanism and appears to be more important in R than in S plants. In conclusion, the increased sensitivity to photoinhibition of resistant plants is not caused by a lower activity of the photoprotective pathways of zeaxanthin formation and photorespiration. The shadetype characteristics of the chloroplasts of the resistant plants are important for the greater sensitivity to photoinhibition.

    Because qN includes several components, research has been performed to study the role of these components and the role of photochemical quenching (qP) in the differences between R and S in their sensitivity to photoinhibition (Chapter 5). The lower qP in the R plants is explained by a larger absorbance cross section of photosystem II (PSII) in the shadetype chloroplasts of the R plants, which enhances the odds of excitation of PSII. In combination with a reduced rate of electron flow at the reducing side of PSII, a higher excitation pressure causes an increase in the fraction of closed reaction centers. The observed lower qE in the R biotype is suggested to be due to a lower PSII electron flow rate and a lower photosynthetic control in R compared with that in S, leading to a smaller proton gradient across the thylakoid membrane. From these findings, it was concluded that the lower energy dissipation through qP and qE cause the greater sensitivity to photoinhibition of resistant plants in vivo.

    The last topic of this research, was the study of the effect of several inhibitors of the different energy dissipative mechanisms (qE, qT) to examine of the contribution of these mechanisms to photoprotection (Chapter 6). Addition of these inhibitors was found to lead to increased photoinhibitory damage, especially in the R biotype.

    In summary, triazine-resistant plants behave like shade-type plants and are adapted to low light irradiances (maize field, forests). The wild-type Chenopodium, a typical sun plant, has more tendency to grow in the open field (road-side, meadow). When R is exposed incidentally or permanently to high irradiance, it will suffer more photoinhibitory damage than the wild biotype (S). The R biotype will be retarded in growth and development due to lack of sufficient activity of photoprotective mechanisms and photosynthetic capacity.

    De groei van het aardappelgewas hangt af van de hoeveelheid zonlicht
    Haverkort, A.J. ; Uenk, D. ; Waart, M. van de - \ 1996
    Aardappelwereld 50 (1996). - ISSN 0169-653X - p. 33 - 37.
    groei - licht - fotoperiodiciteit - aardappelen - solanum tuberosum - growth - light - photoperiodism - potatoes
    Quantifying the effects of temperature and photoperiod on phenological development to flowering in rice
    Yin, X. - \ 1996
    Agricultural University. Promotor(en): M.J. Kropff, co-promotor(en): J. Goudriaan. - S.l. : Yin - ISBN 9789054855156 - 173
    rijst - oryza sativa - groei - gewassen - licht - fotoperiode - fotoperiodiciteit - schaduw - bloei - computersimulatie - simulatie - simulatiemodellen - rice - oryza sativa - growth - crops - light - photoperiod - photoperiodism - shade - flowering - computer simulation - simulation - simulation models

    Accurate prediction of crop phenology is important not only for modelling purposes but also for crop improvement and management actions. The objective of this study was to develop a model for predicting phenological development to flowering in rice ( Oryza sativa L.).

    Data from the literature were analysed to evaluate a basic equation for crop development. The Beta function, commonly used as a skewed probability density function in statistics, was found to accurately describe responses of rice development rate to both temperature and photoperiod. Controlled-environment experiments were then conducted for detailed understanding of the physiological basis of photothermal responses of preflowering development in rice. Effects of day and night temperature on development to flowering were found to be different. The plants did not respond to photoperiod throughout the entire preflowering period, instead, the photoperiod- sensitive phase was sandwiched by two photoperiod-insensitive phases. It appeared that responses to both day and night temperature were stronger during the photoperiod-sensitive phase than during the two photoperiod-insensitive phases. The results also indicated that leaf appearance occurring simultaneously during the preflowering development had a different thermal response from that of the development per se .

    Based on the experimental results, a detailed model for photothermal responses of flowering in rice was developed, using the Beta function. The model, referred to as the three-stage Beta (3s-Beta) model, describes different photothermal responses during the photoperiod-sensitive phase and the photoperiod-insensitive phases of preflowering ontogeny. Using parameter values derived from controlled-environment experiments, the 3s-Beta model adequately predicted rice flowering dates observed in field conditions. It preformed better than several existing models over a wide range of environments.

    In order to assist new plant type design, the 3s-Beta model was applied to determine optimal preflowering phenological traits of rice for an increased yield potential in three different irrigated environments in Asia.

    The results of this thesis were discussed in view of the experimental findings, the methodology of phenology modelling and model applications.

    Literatuurstudie groei en ontwikkeling onder invloed van licht
    Bakker, J.A. ; Blacquiere, T. - \ 1995
    Aalsmeer : Proefstation voor de Bloemisterij (Rapport / Proefstation voor de Bloemisterij 199) - 28
    kunstlicht - licht - verlichting - sierplanten - fotoperiodiciteit - overzichten - artificial light - light - lighting - ornamental plants - photoperiodism - reviews
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