Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    We have a manual that explains all the features 

    Current refinement(s):

    Records 1 - 20 / 210

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    From species to trait evolution in Aethionema (Brassicaceae)
    Mohammadin, Setareh - \ 2017
    Wageningen University. Promotor(en): M.E. Schranz. - Wageningen : Wageningen University - ISBN 9789463431385 - 125
    brassicaceae - evolution - rna - genomes - genetic diversity - phytogeography - glucosinolates - quantitative trait loci - next generation sequencing - brassicaceae - evolutie - rna - genomen - genetische diversiteit - plantengeografie - glucosinolaten - loci voor kwantitatief kenmerk - next generation sequencing

    The plant family Brassicaceae (or crucifers) is an economically important group that includes many food crops (e.g. cabbages and radishes), horticultural species (e.g. Draba, Iberis, Lunaria), and model plant species (particularly Arabidopsis thaliana). Because of the fundamental importance of A. thaliana to plant biology, it makes the Brassicaceae an ideal system for comparative genomics and to test wider evolutionary, ecological and speciation hypotheses. One such hypothesis is the ‘Whole Genome Duplication Radiation Lag Time’ (WGD-RLT) model for the role of polyploidy on the evolution of important plant families such as the Brassicaceae. The WGD-RLT model indicates a higher rate of diversification of a core-group compared to its sister group, due to a lag time after a whole genome duplication event that made it possible for novel traits or geo- or ecological events to increase the core groups diversification rate.

    Aethionema is the species-poor sister genus of the core Brassicaceae and hence is at an important comparative position to analyse trait and genomic evolution of the species-rich core group. Aethionema species occur mainly in the western Irano-Turanian region, which is concordantly the biodiversity hotspot of the Brassicaceae family. Moreover comparing Aethionema to the Brassicaceae core group can help us to understand and test the ‘WGD-RLT’ model. However to be able to do so we first need to know more about Aethionema. In this thesis, I investigated various levels of evolutionary change (from macro, to micro to trait evolution) within the genus Aethionema, with a major focus the emerging model species Aethionema arabicum.

    Next generation sequencing has made it possible to use the genomes of many species in a comparative framework. However, the formation of proteins and enzymes, and in the end the phenotype of the whole plant, relies on transcription from particular regions of the genome including genes. Hence, the transcriptome makes it possible to assess the functional parts of the genome. However, the functional part of the genome not only relies on the protein coding genes. Gene regulatory elements like promoters and long non-coding RNAs function as regulators of gene expression and hence are involved in increasing or decreasing transcription. In Chapter 2 I used the transcriptome of four different Aethionema species to understand the lineage specificity of these long non-coding RNAs. Moreover in a comparison with the Brassicaceae core group and Brassicaceae’s sister family the Cleomaceae I show that although the position of long non-coding RNAs can be conserved, their sequences do not have to be.

    Most of the Aethionema species occur in the Irano-Turanian region, a politically instable region, making it hard for scientist to collect from. However the natural history collections made throughout the last centuries are a great resource. Combing these collections with the newest sequencing techniques, e.g. next generation sequencing, have allowed me to infer the phylogeny of ~75% of the known Aethionema species in a time calibrated and historical biogeographical framework. Hence, I was able to establish that Aethionema species likely originated from the Anatolian Diagonal and that major geological events like the uplift of the Turkish and Iranian plateau have had a hand in their speciation (Chapter 3).

    To examine species-level processes I sequenced and analysed transcriptomes of eight Ae. arabicum accessions coming from Cyprus, Iran and Turkey to investigate population structure, genetic diversity and local adaptation (Chapter 4). The most prominent finding was a ploidy difference between the Iranian and Turkish/Cypriotic lines, whereby the former were (allo)tetraploid and the latter diploid. The tetraploid Iranian lines seem to have one set of alleles from the Turkish/Cypriotic gene-pool. However we do not know where the other alleles come from. In addition to the differences in ploidy level there are also differences in glucosinolate defence compounds between these two populations (Iranian vs Turkish/Cypriotic), with the Iranian lines lacking the diversity and concentration of indolic glucosinolates that the Turkish/Cypriotic lines have. This chapter serves as a good resource and starting point for future research in the region, maybe by using the natural history collections that are at hand.

    Glucosinolates (i.e. mustard oils) are mainly made by Brassicales species, with their highest structural diversity in the Brassicaceae. In Chapter 5, I examined two Ae. arabicum lines (CYP and TUR) and their recombinant inbred lines to assess glucosinolate composition in different tissues and throughout the plants development. The levels of glucosinolates in the leaves changed when Ae. arabicum went from vegetative to a reproductive state. Moreover, a major difference in glucosinolate content (up to 10-fold) between CYP and TUR indicates a likely regulatory pathway outside of the main glucosinolate biosynthesis pathway. Multi-trait and multi-environment QTL analyses based on leaves, reproductive tissues and seeds identified a single major QTL. Fine mapping this region reduced the interval to only fifteen protein coding genes, including the two most intriguing candidates: FLOWERING LOCUS C (FLC) and the sulphate transporter SULTR2;1. These findings show an interesting correlation between development and defence.

    Finally, Chapter 6 gives a final discussion of this thesis and its results. It brings the different topics together, put them in a bigger picture and look forward to new research possibilities.

    Concealed diversity : taxonomical, phytogeographical and phytosociological notes on brambles (Rubus L. subgen. Rubus) in north-west Europe
    Haveman, Rense - \ 2017
    Wageningen University. Promotor(en): Joop Schaminee, co-promotor(en): Rienk Jan Bijlsma. - Wageningen : Wageningen University - ISBN 9789463431019 - 200
    rubus - diversity - taxonomy - phytogeography - geographical distribution - biogeography - apomixis - northwestern europe - rubus - diversiteit - taxonomie - plantengeografie - geografische verdeling - biogeografie - apomixis - noordwest-europa

    Rubus subgen. Rubus (bramble) is one of the large plant genera in Europe, consisting of only a few sexual biological species and at least 700 apomictic lineages. In this thesis, it is argued that the stabilised apomict lineages should best be regarded species, even if their distribution area doesn’t meet the requirements of a regional species as defined in several publications by Weber. Included is a checklist of Dutch bramble species, comprising 191 species belonging to Rubus subgen. Rubus. In the Netherlands, 97 of the 191 species are classified as regional species, with a distribution area diameter under 500 km. On the basis of distribution data of bramble species in Ireland, the UK, Denmark, Germany, and the Netherlands, 12 phytogeographical bramble-regions are distinguished. Although ecological factors play a role in the realisation of these regions, it is argued that the found patterns are primarily the result of evolutionary processes. The density and species composition of Rubus scrubs in the Netherlands is studied using landscape transects. At landscape scale, the bramble species in the scrubs are not randomly distributed, causing a spatial clustering of floristically similar bramble scrubs. It was concluded that only a part of the diversity of Rubus scrubs was accounted for in the Dutch national vegetation classification, and a new scrub type (the Rubetum taxandriae) was described on the basis of these findings. Rubus scrubs are an important biotope for rare shrub species and endemic Rubus species. Additionally, scrubs rich in bramble species are important because they provide foraging and nesting habitats for numerous vertebrates and invertebrates. It is recommended to include the apomict Rubus species in biodiversity accounts, for instance in the national standard list of plant species, as well as the Red List.

    The mountain vegetation of South Peru : syntaxonomy, ecology, phytogeography and conservation
    Montesinos-Tubée, D.B. - \ 2016
    Wageningen University. Promotor(en): Karle Sykora; Frank Berendse, co-promotor(en): Antoine Cleef. - Wageningen : Wageningen University - ISBN 9789462576797 - 334
    vegetation - mountains - phytogeography - ecology - taxonomy - nature conservation - andes - peru - vegetatie - gebergten - plantengeografie - ecologie - taxonomie - natuurbescherming - andes - peru


    This thesis presents an overview and revision of plant communities from xerophytic and mountain landscapes in the dry Andes of South Peru. The revision is based on comparison of the collected vegetation data with other regional and interregional studies. This phytosociologic overview comprises the arid and semi-arid montane vegetation of the province of Arequipa and besides the plant communities of Moquegua from the prepuna between 3470 and 3700 m, the puna between 3750 and 4500 m and the superpuna between 4450 and 4800 m. The Braun-Blanquet approach and multivariate ordination and classification methods have been applied to classify the different plant communities and to study the relation between plant communities and environmental variables, such as altitude, slope degree and exposition, rock and stone cover percentage, manure cover and grazing. Furthermore the results are presented of a phytogeographical analysis of the Andean puna flora (at vascular genus level) and its relation to other tropicalpine regions in South America. Finally, the descriptions of six recently published new species are included in this thesis. The results provide an important database for nature conservation issues, stressing the significance of protecting the fragile and diverse ecosystems of the Moqueguan Andes. The results of this vegetation survey can be used to prioritize the selection and assignment of nature reserves.

    Patterns of exotic plant species in the Netherlands: a macroecological perspective
    Speek, T.A.A. - \ 2015
    Wageningen University. Promotor(en): Wim van der Putten, co-promotor(en): Bert Lotz. - Wageningen : Wageningen University - ISBN 9789462572898 - 158
    geïntroduceerde soorten - vegetatie - plantengeografie - invasieve soorten - plantengemeenschappen - dominantie - nederland - introduced species - vegetation - phytogeography - invasive species - plant communities - dominance - netherlands
    In dit proefschrift heb is onderzocht wat mogelijkheden zijn om het invasief potentieel van geïntroduceerde plantensoorten en de invasibiliteit van plantengemeenschappen in Nederland te voorspellen. Soorten zijn gebruikt die hier al geïntroduceerd zijn, omdat van deze hun invasief succes bekend is. Om hun invasiviteit te kwantificeren is informatie gebruikt over de regionale en lokale verspreiding. De unieke beschikbaarheid van deze datasets voor plantensoorten in Nederland bieden nieuwe kansen, die mogelijk helpen de voorspelbaarheid van invasiviteit te verhogen, uit te leggen hoe invasiviteit van een soort kan veranderen in de tijd en hoe de samenstelling van de plantengemeenschap kan bepalen welke geïntroduceerde soorten zich kunnen vestigen.
    Checklist and distribution data of Dutch brambles (Rubus L. subgenus Rubus) = Naamlijst en verspreidingsgegevens van de Nederlandse bramen (Rubus L. subgenus Rubus)
    Beek, B. van de; Bijlsma, R.J. ; Haveman, R. ; Meijer, K. ; Ronde, I.D. ; Troelstra, A. ; Weeda, E.J. - \ 2014
    Gorteria 36 (2014)4-6. - ISSN 0017-2294 - p. 108 - 171.
    bramen - rubus loganobaccus - plantengeografie - soortendiversiteit - blackberries - rubus loganobaccus - phytogeography - species diversity - rosaceae
    In Noordwest-Europa is de taxonomie van bramen (Rubus.L. subgenus Rubus) goed op orde en de verspreiding van bramen in de verschillende landen goed bekend dankzij herbarium- en veldonderzoek vanaf de jaren 1970. In Nederland dateert onderzoek aan bramen pasvan na 1900 met een actieve periode na de Tweede Wereldoorlog. Dit resulteerde in 1956 in de Rubi Neerlandici door W. Beijerinck, een overzicht gebaseerd op de kunstmatig soortsopvatting van H. Sudre (Rubi Europae; 1908-1913). Het moderne, op typemateriaal en veldwerk gebaseerde onderzoek startte begin jaren 1970 en resulteerde in de decennia erna tot de herkenning en beschrijving van tal van nieuwe regionale soorten en nieuwe namen voor verkeerd geïnterpreteerde soorten.
    Systematics, evolution and historical biogeography of the family Ochnaceae with emphasis on the genus Campylospermum
    Bissiengou, P. - \ 2014
    Wageningen University. Promotor(en): Marc Sosef, co-promotor(en): Lars Chatrou; L. Ngok Banak. - Wageningen : Wageningen University - ISBN 9789462572225 - 357
    ochnaceae - biosystematiek - taxonomie - evolutie - biogeografie - plantengeografie - fylogenie - taxonomische revisies - fylogenetica - ochnaceae - biosystematics - taxonomy - evolution - biogeography - phytogeography - phylogeny - taxonomic revisions - phylogenetics


    Ochnaceae s.l. is a family of trees, shrubs or rarely herbs widely distributed in tropical and subtropical forests and savannas of the Old and New World, and has about 500 species in 32 genera. The family is divided into three subfamilies: Medusagynoideae, Quiinoideae and Ochnoideae. We have provided, for the first time, a nearly complete molecular phylogenetic analysis of Ochnaceae s.l. resolving most of the phylogeny backbone of the family using five DNA regions. Based on this, dating analyses were performed using a secondary calibration, and relaxed molecular clock models. The historical biogeography of Ochnaceae s.l. was reconstructed using Dispersal-Vicariance Analysis and Bayesian Binary MCMC. The Neotropics were inferred as being the geographical origin of the family and the Old World was most likely colonized via the North Atlantic Land Bridge during a period when climatic conditions allowed establishment of a boreotropical flora. A full taxonomic revision of the continental African species of the genus Campylospermum has been prepared and additional historical biogeographic analyses were performed with a focus on the genus Campylospermum.

    Functional traits, drought performance, and the distribution of tree species in tropical forests of Ghana
    Amissah, L. - \ 2014
    Wageningen University. Promotor(en): Frits Mohren, co-promotor(en): Lourens Poorter; B. Kyereh. - Wageningen : Wageningen University - ISBN 9789462570726 - 196
    tropische bossen - bomen - droogteresistentie - plantengeografie - bosecologie - regen - temperatuur - plantenfysiologie - ghana - tropical forests - trees - drought resistance - phytogeography - forest ecology - rain - temperature - plant physiology - ghana

    Tropical forests occur along a rainfall gradient where annual amount, the length and intensity of dry season vary and water availability shapes therefore strongly the distribution of tree species. Annual rainfall in West Africa has declined at a rate of 4% per decade, and climate change models predict a further reduction in rainfall and an increase in frequency and intensity of drought. This will have large consequences for the diversity, composition and distribution of tropical tree species. Understanding the factors that shape tree species distribution will help to understand current forest functioning and to predict the potential impact of climate change on forests.

    In this thesis, I used a combination of forest inventory data, greenhouse and field experiments to determine the responses of 10-23 species to drought and shade, and analyse the underlying mechanisms. I addressed 4 questions: (1) What is the relative importance of rainfall and temperature on tree species distribution? (2) How do tree species acclimatise to drought and shade in terms of their physiology, morphology, growth and survival? (3) What morphological and physiological traits determine species drought performance and distribution? (4) How do seedling survival, growth and physiology vary between dry and wet forests, and does drought tolerance and growth determine species distribution along the rainfall gradient?

    Forest inventory data showed that the distribution of 95% of 20 species was significantly associated with annual rainfall, 60% with rainfall seasonality, 45% with isothermality and 40% with temperature seasonality. Thus, a reduction in annual rainfall, and an increase in frequency and intensity of drought as predicted by climate change models may affect the distribution of many tree species. A greenhouse experiment indicated that shade facilitated the survival of seedlings subjected to drought, rather than reducing it. This contrasts with the trade-off hypothesis that suggests a stronger impact of drought in shade conditions. Across 23 species, I found a trade-off between drought avoidance (by a deciduous leaf habit during drought) and physiological drought tolerance (by having tough and persistent tissues that allow plants to function during drought) strategies. These strategies were closely associated with species’ shade tolerance and growth rates. A suite of functional traits predicted drought survival and tree species position on the rainfall gradient. Across species, drought survival was enhanced by having less biomass allocation to transpiring leaves, a low leaf area per unit plant mass, and by dense and tough leaf and wood tissues that allow plants to function during drought. The field experiment showed that drought survival (and growth) in the dry forest relative to the wet forest correlated negatively with species position on the rainfall gradient. Hence, species that survive and grow relatively well in dry forests are found at the drier end of the rainfall gradient. This suggests that species sensitivity to low water availability determines the distribution of tree species. The predicted increase in drought frequency and intensity may, therefore, cause a shift in the distribution of tree species in tropical forests.

    Fenotypische plasticiteit en nomenclatuur van Melkviooltje (Viola stagnina - V. persicifolia nom. ambig. propos.)
    Hof, K. van den; Marcussen, Th. ; Berg, R.G. van den; Weeda, E.J. ; Gravendeel, B. - \ 2013
    Gorteria 36 (2013)3. - ISSN 0017-2294 - p. 60 - 84.
    flora - nomenclatuur - plantengeografie - flora - nomenclature - phytogeography
    Op basis van al eerder gevonden genetische en morfologische verschillen en de uitkomsten van de hier gepresenteerde gegevens wordt voorgesteld dat de endemische vorm van V. stagnina als aparte variëteit lacteoides erkend moet blijven. Voor de taxonomische status van aparte (onder)soort verschillen de twee vormen nog te weinig en overlappen ze geografisch teveel.
    Veldgids Paddenstoelen I : 500 soorten plaatjeszwammen en boleten
    Dam, N.J. ; Kuyper, T.W. - \ 2013
    Zeist : KNNV uitgeverij - ISBN 9789050114639 - 423
    schimmels - mycologie - flora - determinatietabellen - plantengeografie - nederland - fungi - mycology - keys - phytogeography - netherlands
    Zelf paddenstoelen herkennen kun je nu met deze nieuwe Veldgids paddenstoelen. De veldgids beschrijft 500 algemene soorten plaatjeszwammen en boleten van Nederland. Deze dekken ruim 95 procent van alle in Nederland geregistreerde waarnemingen - en daarmee is dit boek uniek in ons taalgebied.
    Kroonjuwelen van de Kaap
    Sluiter, L. ; Schaminee, J.H.J. - \ 2012
    Zeist : KNVV - ISBN 9789050114301 - 191
    plantenecologie - vegetatie - natuurbescherming - biodiversiteit - plantengeografie - fijnbos (zuid afrika) - lokale geschiedenis - inheemse volkeren - flora - westkaap - zuid-afrika - plant ecology - vegetation - nature conservation - biodiversity - phytogeography - fynbos - local history - indigenous people - western cape - south africa
    'Kroonjuwelen van de Kaap' neemt de fascinerende wereld van de Kaap onder de loep. Niet alleen de biologische rijkdom van het fynbos, maar ook de geschiedenis van het gebied en zijn bewoners. Na eeuwenlang op zichzelf te hebben geleefd, in nauw samenspel met de natuur, kregen de oorspronkelijke bewoners, de Khoikhoi en de San, vanaf de zeventiende eeuw te maken met kolonialisme, en de daaruit voortgekomen apartheid. Recente ontwikkelingen, waaronder de grootschalige teelt van rooibosthee, zetten het kwetsbare gebied en haar oeroude bevolking sterk onder druk. Maar dankzij lokale initiatieven doen duurzaamheid en eerlijke handel geleidelijk hun intrede. 'Kroonjuwelen van de Kaap' is een beeldende reportage van een bijzonder gebied en de mensen die er wonen en werken. Natuurbeschermers, wetenschappers en de lokale bevolking komen aan het woord. Het eerste deel van het boek stelt de natuur centraal, het tweede deel gaat over het menselijk gebruik van het fynbos en de vragen die dit oproept.
    Characterization of African Bush Mango trees with emphasis on the differences between sweet and bitter trees in the Dahomey Gap (West Africa)
    Vihotogbe, R. - \ 2012
    Wageningen University. Promotor(en): Marc Sosef; B. Sinsin, co-promotor(en): Ronald van den Berg. - [S.l. : S.n. - ISBN 9789461734129 - 189
    irvingia - domesticatie - bomen - plantenmorfologie - plantengeografie - genetische diversiteit - taxonomie - smaken - benin - west-afrika - irvingia - domestication - trees - plant morphology - phytogeography - genetic diversity - taxonomy - tastes - benin - west africa

     African bush mango trees (ABMTs) are economically the most important species within the family of Irvingiaceae. They are priority trees producing non-timber forest products (NTFPs) and widely distributed in the humid lowland forests of West and Central Africa. To boost their production and develop them towards a major crop for rural communities in Africa, a domestication program was initiated in the 2000s which is being coordinated by the World Agroforestry Centre. ABMTs belong to two taxa, one with sweet and one with bitter fruits which are morphologically difficult to distinguish. The fresh mesocarp of the sweet bush mangoes are consumed, while the seed of both bitter and sweet fruits are an important component of the African diet. The high oil content of this seed further increases their potential use.

     Apart from the overlap of their morphological characters, the ecological and phenological distinction between sweet and bitter ABMTs is unclear due to: (i) the lack of comparative quantitative data and (ii) the lack of centralizing the existing country-level databases. Therefore, their taxonomic status is still not clear. Do they represent distinct species or varieties or are they mere forms within the same gene pool? It is also unclear whether the occurrence of ABMTs in traditional agroforestry systems in the Dahomey Gap, the dry savannah corridor between the Upper and Lower Guinean rain forest blocks, forms part of the natural distribution or not . Moreover, genetic studies addressing ABMTs diversity have been geographically restricted, and conclusions regarding the taxonomic status of sweet and bitter trees were not unanimous.

    This study was conducted in a perspective of developing suitable strategies for the conservation and use of ABMTs, mostly in the Dahomey Gap. First, differences in ethnobotanical knowledge of the major socio-cultural groups in the Dahomey Gap were linked to the agroforestry status of ABMTs. This was used to explain the characteristics of the spatial pattern of ABMTs abundance and the anthropogenic factors that govern this spatial structure as well as population survival in the Dahomey Gap. Second, occurrence data of wild and cultivated ABMTs were used in a species distribution modelling algorithm to calculate the niche space and potential distribution of bitter and sweet trees in Tropical Africa. The differences in the obtained distribution patterns were compared using ENM-Tools. Third, detailed monthly phenological data and morphological characteristics (qualitative as well as quantitative measurements on the leaves, bark, fruits, and seeds) were used to analyse the diversity of ABMTs and to discover differences between them in order to be able to identify bitter and sweet trees in the field. Finally, the molecular markers AFLP and cpSSR were used in order to map the genetic diversity of ABMTs and to discriminate sweet and bitter trees across Togo, Benin, Nigeria and Cameroon.

    The consumption of mesocarp and seed of bush mangoes is widely known throughout the Dahomey Gap. The level of knowledge within local communities of other types of uses (medical, social-cultural) is generally poor and decreases towards the western part of this region. This suggests that ABMTs (mostly the sweet trees) were introduced in this eco-region through the migration of human populations from the Lower Guinean forest block (Southeast Nigeria) to the West. In the Dahomey Gap, bitter trees are confined to the Volta forest region, a small-sized ecological area in south-western Togo. While low densities (< 462 trees per 25 ha) were recorded for wild bitter trees occurring in the Volta forest region, higher densities (up to 1020 trees per 25 ha) were found for sweet trees in human made agro-systems. This implies a clear difference in cultivation methods between bitter and sweet ABMTs. The intensive cultivation of ABMTs in the Dahomey Gap is influenced by farmland status, farmer’s socio-cultural group and type of ABMT. Small and exhausted farmlands are converted into sweet ABMT orchards indicating that their development is a small-scale process lead by individual farmers. Slash and burn agriculture and intensive collection of fruits for seed commercialization jeopardize bitter trees, while traditional fishing systems (using twigs), traditional mass selection strategy, and intensive land commercialization severely threaten sweet trees genetic resources.

    Using species distribution modelling, the potential distribution of wild sweet trees was predicted in the wetter zones of the Guinean-Congolian phytogeographical region, while that of bitter trees extended to drier zones in the Guineo-Congolia/Sudania and Lake Victoria regions. This difference is significant, supporting the idea that bitter and sweet trees belong to two different species. In the Dahomey Gap, bitter trees occur in the wild in the wettest ecological region of the Volta forest region which is a very small part of the Dahomey Gap. This region is ecologically particular among the ecosystems in which wild bitter trees generally occur. We also conclude that in the Dahomey Gap sweet trees occur only in cultivation.

    Within the Dahomey Gap, clear phenological differences exist between sweet and bitter ABMTs, mostly in their reproduction phases. Moreover, their reproductive success significantly depends on the type of ABMT, soil, climate and season and we conclude there is a low probability of hybridization between sweet and bitter trees in the area where they co-occur.

    The qualitative morphological characters, the type of bark, colour of the mature fruit exocarp and mesocarp, and fruit roughness, do not consistently discriminate bitter and sweet trees in the field. We strongly recommend broadening the geographic area of this study by increasing more bitter trees as well as the wild samples of both taxa to validate this conclusion. The bitter trees in the Volta forest region produce the heaviest seeds and this consistently distinguishes them from all the sweet trees sampled in the Dahomey Gap. However, a combination of quantitative morphological characters (from fruits, mesocarp, and seeds) failed to discriminate populations. On the other hand this indicates the presence of a high diversity and thus high potential for selection across all phytogeographical regions. However, domestication and climate appear to be playing a key role in the morphological differentiation of Dahomey Gap populations, and evidence of success in the traditional domestication and selection of sweet trees is proven.

     Low genetic diversity was found for the bitter trees occurring in the Volta forest region in the Dahomey Gap due to the high fragmentation of the small-sized forest ecosystem in which they occur and the continuous reduction of the population size. The higher polymorphism and genetic diversity observed in the sweet tree population in Benin and Togo indicate the effect of domestication of material from different geographical origins as well as a frequent long distance transfer of genetic material. When used separately, the AFLP and cpSSR data failed to consistently discriminate geographical populations and bitter from sweet trees. But a combined dataset of both markers tends to differentiate such populations as well as tree types. Our results also provide evidence that the suitability of AFLPs and cpSSRs to assess genetic diversity patterns in Irvingia material needs to be thoroughly reassessed.

    Finally, although admitting that a broader study remains necessary, based on the presence of a consistent gap between both taxa regarding their reproductive periods, their different ecology and, of course, the consistent difference in taste of the fruit, we advise to treat the sweet and bitter ABMTs as two taxonomically different entities at species level: Irvingia gabonensis (Aubry-LeComte ex O’Rorke) Baill. and I. wombolu Vermoesen, respectively.

    An ecogeographic analysis of Oryza series Sativae in Asia and the Pacific
    Banaticla-Hilario, M.C.N. - \ 2012
    Wageningen University. Promotor(en): Marc Sosef, co-promotor(en): Ronald van den Berg; K.L. McNally. - S.l. : s.n. - ISBN 9789461733788 - 237
    oryza - oryza sativa - oryza nivara - genetische bronnen van plantensoorten - plantengeografie - plantenecologie - diversiteit - in-situ conservering - plantenmorfologie - taxonomie - genetica - genenbanken - azië - oryza - oryza sativa - oryza nivara - plant genetic resources - phytogeography - plant ecology - diversity - in situ conservation - plant morphology - taxonomy - genetics - gene banks - asia

    The non-cultivated speciesof the genus Oryza can provide a genetic arsenal of useful traits for improving the widely cultivated and consumed Asian rice (O. sativa). The diversity of these valuable plant resources must be well understood to ensure their effective in- and ex-situ conservation. In this thesis, we examined the ecogeographic variations within and between the three species of Oryza series Sativae in Asia and the Pacific. We looked at species differentiation from different spatial scales by analysing sympatric accession pairs of O. meridionalis and O. rufipogon and of O. nivara and O. rufipogon.

    We conducted phenotypic analyses in Chapter 2. The strong influence of ecology on species morphology was demonstrated in the ordination and cluster analyses results where O. meridionalis and O. nivara grouped together and were separated from O. rufipogon. We detected greater differentiation of O. nivara and O. rufipogon in South Asia and positive correlations between spatial and intraspecific (interpopulation) morphological distances in continental Asia. We found significant correlations between geoclimatic factors and certain character measurements within species and observed that seedling height, culm number and diameter, leaf size, and anther length exhibit contrasting responses for O. nivara and O. rufipogon. We confirmed significant morphological differences between the three species, between the South and Southeast Asian populations of O. nivara, and between the Australasian and the non-Australasian populations of O. rufipogon and provided botanical descriptions to delineate O. meridionalis, O. nivara and O. rufipogon morphologically.

    In Chapter 3, we genotyped the same set of accessions with 29 SSR markers and applied a variety of methods for genetic diversity analysis. Based on ordination and phylogenetic results, we verified that O. meridionalis is a genetically distinct species and that O. nivara and O. rufipogon overlap genetically across their geographic distribution. However, Bayesian clustering analysis recognized local-scale species separation of O. nivara and O. rufipogon implying stronger interspecific gene flow barriers in smaller spatial units. Concurrently, AMOVA indicated that the bulk (64%) of genetic variation in Asia Pacific series Sativae can be found among accessions and the lesser portions within accessions (26%) and among species (10%). We captured contrasting intraspecific variation patterns for O. nivara and O. rufipogon where the former exhibited low diversity, high population differentiation and isolation by distance mainly in South Asia while the latter displayed high diversity, low population differentiation and isolation by distance primarily in continental Southeast Asia. We established that altitude is correlated negatively to accession diversity and positively to local-scale species differentiation. Using Bayesian inference, we identified eight genetically distinct population groups: C1) Indian and Bangladeshi O. nivara; C2) Cambodian O. nivara; C3) Southeast Asian O. rufipogon; C4) O. meridionalis; C5) Nepalese O. nivara; C6) non-Cambodian Southeast Asian O. nivara; C7) Australasian O. rufipogon; and C8) South Asian O. rufipogon. Cluster analysis grouped the aromatic and japonica cultivar groups of O. sativa with O. rufipogon in South Asia and the indica and aus groups with O. nivara from Thailand and Cambodia, respectively. O. nivara from Nepal seemed genetically isolated from the other population groups. We also detected variation patterns that agreed with the results in Chapter 1 such as the South and Southeast Asian divisions of O. nivara, the divergence of Australasian populations from the rest of O. rufipogon and the greater differentiation of O. nivara and O. rufipogon in South Asia.

    In Chapter 4, we conducted artificial crossing experiments to 15 selected parental accessions of O. meridionalis, O. nivara, and O. rufipogon and assessed the extent of several post-pollination isolating mechanisms in Oryza series Sativae. We observed reproductive incompatibility within and between the inbreeding species O. meridionalis and O. nivara and high intraspecific crossability of the outcrossing O. rufipogon where viable and non-sterile F1 hybrids were produced only by combinations with a parental distance that ranged from 1062 to 3813 kilometers. Insular Southeast Asian and/or Australasian accessions of O. rufipogon were the most reproductively successful parents. O. rufipogon exhibited significant pre-zygotic species isolation (in terms of seed set) and reduced post-zygotic isolation, and seemed symmetrically compatible with O. nivara and asymmetrically compatible with O. meridionalis. We obtained few annual hybrids with relatively high fertilities from crosses between O. rufipogon and O. nivara and numerous perennial hybrids with low fertilities from crosses between O. rufipogon and O. meridionalis. Crossability estimates did not show significant correlations with geographic distance between parents. However, we discerned reduced seed set and F1 fertility in interspecific combinations with sympatric parents compared to crosses with non-sympatric parents, indicative of reinforced species isolation in sympatry. We evaluated the F1 offspring of different cross combinations and found a mixture of intermediate and parental character traits in interspecific hybrids.

    We discussed the taxonomic implications of the research results in Chapter 5 where we specifically dealt with the opposing views of lumping or splitting of O. nivara and O. rufipogon. We concluded that these two taxadeserve to be treated as separate species based on the following biosystematic evidence obtained from the thesis: 1) ecological distinction; 2) considerable prezygotic barriers; 3) opposing patterns of gene flow and genetic variation; 4) local-scale genetic divergence and 5) enhanced reproductive barriers under sympatric conditions. We identified ecogeography as a major driving force in the diversification of Oryza series Sativae in Asia and the Pacific and suggested that ecological speciation gave rise to O. nivara and O. rufipogon. We also presented recognizable geographic races within species.

    Ultimately in Chapter 6, we emphasized the importance of our study in several aspects of rice science and identified results that agreed with prior Oryza diversity studies. At the same time, we presented previously unreported morphological and genetic variation patterns that were established in this thesis. We discussed the possible applications of the research results to wild rice conservation, covering in situ strategies as well as gene bank practices. We also highlighted the potential role of O. nivara in Asian rice domestication where it could have either directly given rise to the indica cultivar group or hybridized/introgressed with migrated japonica cultivars in India, eventually leading to the development of indica.

    A landscape ecological vegetation map of Sint Eustatius (Lesser Antilles)
    Freitas, J.A. de; Rojer, A.C. ; Nijhof, B.S.J. ; Debrot, A.O. - \ 2012
    Den Helder : IMARES (Report / IMARES Wageningen UR C053/12) - 61
    flora - plantengeografie - spermatophyta - nederlandse antillen - sint eustatius - vegetatietypen - geomorfologie - vegetatiekartering - flora - phytogeography - spermatophyta - netherlands antilles - sint eustatius - vegetation types - geomorphology - vegetation mapping
    A semi-detailed landscape-based vegetation map (scale: 1: 37,500) based on field data from 1999 has been available as an update of Stoffers’ 1956 map of the Lesser Antillean island of St. Eustatius, Netherlands Caribbean, but up to now was never finalized or published. In this report we complete the documentation of that map to provide new insights into vegetation change over a period of more than 40 years, and a quantitative reference point for future studies on landscape-level vegetation development for the island.
    Plant Resources of Tropical Africa 16 Fibres
    Brink, M. ; Achigan-Dako, E.G. - \ 2012
    Wageningen, Netherlands : PROTA Foundation/CTA (Plant resources of tropical Africa 16) - ISBN 9789290814818 - 602
    vezelgewassen - plantenvezels - soorten - genetische bronnen van plantensoorten - plantengeografie - plantenmorfologie - biologische naamgeving - taxonomie - plantenvermeerdering - tropisch afrika - fibre plants - plant fibres - species - plant genetic resources - phytogeography - plant morphology - biological nomenclature - taxonomy - propagation - tropical africa
    This volume deals with the fibres of Tropical Africa. 515 ‘primary use’ fibres are described in 248 review articles. Many of the articles are illustrated with a geographic distribution map and a line drawing of the habit.
    Veenmossen in het Haaksbergerveen
    Weeda, E.J. - \ 2011
    In: Excursieverslagen 2006 / van Dort, K., Haveman, R., Janssen, J.A.M., Wageningen : Plantensociologische Kring Nederland - p. 104 - 112.
    sphagnum - plantengeografie - vegetatietypen - veengebieden - natura 2000 - twente - overijssel - sphagnum - phytogeography - vegetation types - peatlands - natura 2000 - twente - overijssel
    Het Natura 2000-gebied Haaksbergerveen in Zuid-Twente was in 2006 uitgekozen als terrein voor de jaarlijkse veenmosexcursie. De verscheidenheid aan veenmossen is onder meer te danken aan de invloed van grondwater die op veel plaatsen in het veen speurbaar is. Niet alle genoemde soorten zijn tijdens de excursie waargenomen. De zeldzaamste, S. subsecundum, is alleen in 1980 en 1982 verzameld en werd bij de veenmosrevisie door Gerard Dirkse gewaarmerkt
    Veldgids Plantengemeenschappen
    Schaminee, J.H.J. ; Sykora, K.V. ; Smits, N.A.C. ; Horsthuis, M. - \ 2010
    Zeist : KNNV uitgeverij - ISBN 9789050113090 - 440
    plantengemeenschappen - flora - plantengeografie - plantenecologie - soorten - determinatietabellen - vegetatiekunde - ecologie - nederland - plant communities - flora - phytogeography - plant ecology - species - keys - vegetation science - ecology - netherlands
    Deze gids geeft een compacte beschrijving van alle plantengemeenschappen in Nederland: van open water en moerassen, graslanden en heiden, kust en binnenlandse pioniermilieus, tot ruigten, bossen en struwelen. De gids biedt ook een toegankelijke inleiding over termen en begrippen in de vegetatiekunde. Per plantengemeenschap zijn verspreidingskaartjes, samenvattende tabellen met de belangrijkste soorten en grafieken over standplaats en levensvormen opgenomen. Bovendien bevat het boek determinatiesleutels waarmee de Nederlandse plantengemeenschappen op naam zijn te brengen. De sleutels leiden tot de juiste klasse, waarna aan de hand van standplaatskenmerken en soortensamenstelling op eenvoudige wijze de plantengemeenschap kan worden bepaald.
    Wilde, J.J.F.E. de; Sosef, M.S.M. - \ 2009
    Weikershelm [etc.] : Margraf [etc.] (Flore de Gabon vol. 39) - ISBN 9783823615743 - 109
    begoniaceae - taxonomie - determinatietabellen - identificatie - plantengeografie - gabon - begoniaceae - taxonomy - keys - identification - phytogeography - gabon
    Weidevergeet-mij-nietje blijkt Beemdvergeet-mij-nietje; Myosotis scorpioides subsp. nemorosa nog steeds in Zuid-Limburg
    Weeda, E.J. - \ 2009
    Natuurhistorisch Maandblad 98 (2009)2. - ISSN 0028-1107 - p. 21 - 28.
    vegetatie - bepaalde en onbepaalde habitus - plantengeografie - zuid-limburg - vegetation - determinate and indeterminate habit - phytogeography - zuid-limburg
    Bij een vegetatiekundige inventarisatie van Zuid-Limburgse hellingmoerassen in 2007 en 2008 werd in drie terreinen het Weidevergeet-mij-nietje aangetroffen. De drie recente waarnemingen van dit vergeet-mij-nietje zijn alle drie gedaan in beemden. Beemden vormen een vergeten biotoop. Een typische exponent van deze biotoop vormt deze plant, waarvoor de naam Beemdvergeet-mij-nietje wordt aanbevolen
    Plant resources of tropical Africa 7(1) : timbers 1
    Louppe, D. ; Oteng-Amoake, A.A. ; Brink, M. ; Lemmens, R.H.M.J. ; Oyen, L.P.A. ; Cobbinah, J.R. - \ 2008
    Wageningen [etc.] : PROTA Foundation [etc.] (Plant resources of tropical Africa 7(1)) - ISBN 9789057822094 - 704
    bomen - houtsoorten - taxonomie - biologische naamgeving - soorten - plantengeografie - tropisch afrika - trees - timbers - taxonomy - biological nomenclature - species - phytogeography - tropical africa
    Braamrijke duinstruwelen in Nederland
    Haveman, R. ; Haperen, A.M.M. van - \ 2008
    Stratiotes 2008 (2008)37-37. - ISSN 0928-2297 - p. 63 - 86.
    duinplanten - soorten - plantengeografie - inventarisaties - zuidhollandse eilanden - zeeuwse eilanden - nederlandse waddeneilanden - duneland plants - species - phytogeography - inventories - zuidhollandse eilanden - zeeuwse eilanden - dutch wadden islands
    Tussen 1993 en 2005 zijn gegevens verzameld van duinstruwelen waarin bramen een belangrijke plaats innemen. Di tgebeurde enerzijds tijdens veldwerk dat verricht werd voor de beschrijving van de vegetatie van de duinen van de Zeeuwse en Zuidhollandse duinen in het kader van en dissertatie, anderzijds tijdens de kartering van de vegetatie op enkele militaire terreinen op Texel en Vlieland
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.