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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ICTV Virus Taxonomy Profile : Hytrosaviridae
Kariithi, Henry M. ; Vlak, Just M. ; Jehle, Johannes A. ; Bergoin, Max ; Boucias, Drion G. ; Abd-Alla, Adly M.M. ; Ictv Report Consortium, Report Consortium - \ 2019
Journal of General Virology 100 (2019)9. - ISSN 0022-1317 - p. 1271 - 1272.
Hytrosaviridae - ICTV Report - taxonomy

Hytrosaviridae is a family of large, rod-shaped, enveloped entomopathogenic viruses with dsDNA genomes of 120-190 kbp. Hytrosaviruses (also known as salivary gland hypertrophy viruses) primarily replicate in the salivary glands of adult dipteran flies. Hytrosaviruses infecting the haematophagous tsetse fly and the filth-feeding housefly are assigned to two genera, Glossinavirus and Muscavirus, respectively. Whereas muscavirus infections are only overt, glossinavirus infections can be either covert or overt. Overt infections are characterized by diagnostic salivary gland hypertrophy and cause either partial or complete infertility. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Hytrosaviridae, which is available at ictv.global/report/hytrosaviridae.

DNA barcoding fishes from the Congo and the Lower Guinean provinces: Assembling a reference library for poorly inventoried fauna
Sonet, Gontran ; Snoeks, Jos ; Nagy, Zoltán T. ; Vreven, Emmanuel ; Boden, Gert ; Breman, Floris C. ; Decru, Eva ; Hanssens, Mark ; Ibala Zamba, Armel ; Jordaens, Kurt ; Mamonekene, Victor ; Musschoot, Tobias ; Houdt, Jeroen Van; Steenberge, Maarten Van; Lunkayilakio Wamuini, Soleil ; Verheyen, Erik - \ 2019
Molecular Ecology Resources 19 (2019)3. - ISSN 1755-098X - p. 728 - 743.
biodiversity - Central Africa - COI - freshwater - ichthyofauna - taxonomy

The Congolese and Lower Guinean ichthyological provinces are understudied hotspots of the global fish diversity. Here, we barcoded 741 specimens from the Lower and Middle Congo River and from three major drainage basins of the Lower Guinean ichthyological province, Kouilou-Niari, Nyanga and Ogowe. We identified 194 morphospecies belonging to 82 genera and 25 families. Most morphospecies (92.8%) corresponded to distinct clusters of DNA barcodes. Of the four morphospecies present in both neighbouring ichthyological provinces, only one showed DNA barcode divergence <2.5%. A small fraction of the fishes barcoded here (12.9% of the morphospecies and 16.1% of the barcode clusters representing putative species) were also barcoded in a previous large-scale DNA analysis of freshwater fishes of the Lower Congo published in 2011 (191 specimens, 102 morphospecies). We compared species assignments before and after taxonomic updates and across studies performed by independent research teams and observed that most cases of inconsistent species assignments were due to unknown diversity (undescribed species and unknown intraspecific variation). Our results report more than 17 putative new species and show that DNA barcode data provide a measure of genetic variability that facilitates the inventory of underexplored ichthyofaunae. However, taxonomic scrutiny, associated with revisions and new species descriptions, is indispensable to delimit species and build a coherent reference library.

Data from: DNA barcoding fishes from the Congo and the Lower Guinean provinces: assembling a reference library for poorly inventoried fauna
Sonet, Gontran ; Snoeks, Jos ; Nagy, Zoltán T. ; Vreven, Emmanuel ; Boden, Gert ; Breman, F.C. ; Decru, Eva ; Hanssens, Mark ; Ibala Zamba, Armel ; Jordaens, Kurt ; Mamonekene, Victor ; Musschoot, Tobias ; Houdt, Jeroen Van; Steenberge, Maarten Van; Lunkayilakio Wamuini, Soleil ; Verheyen, Erik - \ 2018
biodiversity - freshwater - taxonomy - COI - Ichtyofauna
The Congolese and Lower Guinean ichthyological provinces are understudied hotspots of the global fish diversity. Here, we barcoded 741 specimens from the Lower and Middle Congo River and from three major drainage basins of the Lower Guinean ichthyological province, Kouilou-Niari, Nyanga and Ogowe. We identified 195 morphospecies belonging to 82 genera and 25 families. Most morphospecies (92.8%) corresponded to distinct clusters of DNA barcodes. Of the four morphospecies present in both neighbouring ichthyological provinces, only one showed DNA barcode divergence <2.5%. A small fraction of the fishes barcoded here (12.9% of the morphospecies and 16.1% of the barcode clusters representing putative species) were also barcoded in a previous large-scale DNA analysis of freshwater fishes of the Lower Congo published in 2011 (191 specimens, 102 morphospecies). We compared species assignments before and after taxonomic updates and across studies performed by independent research teams and observed that most cases of inconsistent species assignments were due to unknown diversity (undescribed species and unknown intraspecific variation). Our results report more than 17 putative new species and show that DNA barcode data provide a measure of genetic variability that facilitates the inventory of underexplored ichthyofaunae. However, taxonomic scrutiny, associated with revisions and new species descriptions, is indispensable to delimit species and build a coherent reference library.
Fusarium metavorans sp. Nov. : The frequent opportunist â € FSSC6'
Al-Hatmi, Abdullah M.S. ; Ahmed, Sarah A. ; Diepeningen, Anne D. Van; Drogari-Apiranthitou, Miranda ; Verweij, Paul E. ; Meis, Jacques F. ; Hoog, G.S. De - \ 2018
Medical Mycology 56 (2018). - ISSN 1369-3786 - p. S144 - S152.
fusariosis - Fusarium metavorans - molecular phylogenetics - morphology - RPB2 - taxonomy - TEF1
The Fusarium solani species complex (FSSC) is the most common group of fusaria associated with superficial and life-threatening infections in humans. Here we formally introduce Fusarium metavorans sp. Nov., widely known as FSSC6 (Fusarium solani species complex lineage 6), one of the most frequent agents of human opportunistic infections. The species is described with multilocus molecular data including sequences of internal transcribed spacer region (ITS), portions of the translation elongation factor 1-a gene (TEF1), and the partial RNA polymerase II gene (rPB2). A phylogenetic approach was used to evaluate species delimitation. Topologies of the trees were concordant. Phylogenetic analyses suggest that the FSSC consists of three major clades encompassing a large number of phylogenetic species; Fusarium metavorans corresponds to phylogenetic species 6 within FSSC clade 3. The species has a global distribution and a wide ecological amplitude, also including strains from soil and agents of opportunistic plant disease; it was also isolated from the gut of the wood-boring cerambycid beetle Anoplophora glabripennis.
Microbiome dynamics of disease suppresive soils
Gómez Expósito, Ruth - \ 2017
Wageningen University. Promotor(en): F.P.M. Govers; J.M. Raaijmakers, co-promotor(en): J. Postma; I. de Bruijn. - Wageningen : Wageningen University - ISBN 9789463431774 - 267
suppressive soils - soil suppressiveness - plant diseases - thanatephorus cucumeris - microbial ecology - soil microbiology - rhizosphere bacteria - soil bacteria - community ecology - soil fungi - transcriptomics - taxonomy - ziektewerende gronden - bodemweerbaarheid - plantenziekten - thanatephorus cucumeris - microbiële ecologie - bodemmicrobiologie - rizosfeerbacteriën - bodembacteriën - gemeenschapsecologie - bodemschimmels - transcriptomica - taxonomie

Disease suppressive soils are soils in which plants do not get diseased from plant pathogens due to the presence (and activities) of the microbes present in the soil. Understanding which microbes contribute to confer suppression and through which mechanisms they can protect plants is crucial for a sustainable control of plant diseases. In the research conducted in this thesis, I first examined the role of Lysobacter species, previously associated with disease suppressive soils, in suppressing damping-off disease caused by the soil-borne fungal pathogen Rhizoctonia solani on sugar beet. The majority of the Lysobacter strains tested revealed a broad metabolic potential in producing a variety of enzymes and secondary metabolites able to suppress R. solani in vitro. However, any of these strains could consistently suppress damping-off disease when applied in soil bioassays. Their ability to promote plant growth was also tested for sugar beet, cauliflower, onion or Arabidopsis thaliana. Results indicated that any of the Lysobacter strains could consistently promote plant growth, neither via direct contact nor via volatile production. Second, I investigated whether the antagonistic activity of Lysobacter species could be triggered when applied as bacterial consortia, together with Pseudomonas and Streptomyces species. Although several bacterial combinations showed an increased antagonistic effect towards R. solani in vitro, no consistent effects were observed when these bacterial consortia were applied in vivo. Third, I investigated the dynamical changes in the bacterial community composition and functions occurring during the process of disease suppressiveness induction by performing whole community analyses using next-generation sequencing techniques. Results indicated that suppressiveness induction was most associated with changes in certain bacterial traits rather than changes in the bacteria community composition itself. Among the functions found as more active in suppressive soils were several ‘classic’ mechanisms of disease suppression, including competition for nutrients, iron and space and production of extracellular enzymes, indol-acetic-acid and hydrogen cyanide. Among the enzymes found in higher abundance in suppressive soil were these ones involved in the degradation of oxalic acid, a pathogenicity factor produced by pathogenic fungi to help infecting the host plant. Hence, I finally studied the role of bacteria able to produce enzymes able to degrade oxalic acid in suppressing R. solani disease. Enrichment of native oxalotrophic bacteria existing in soil, their isolation and further application into soil revealed that they could effectively suppress Rhizoctonia disease. Characterization of these oxalotrophic bacteria revealed that members within the Caulobacter and Nocardioides species could suppress R. solani disease by their own. Furthermore, the research done in this thesis highlights the importance of combining different techniques to unravel the mechanisms underlying disease suppression and the importance of studying function-over-phylogeny. Additionally, it also highlights the importance of organic amendments (such as oxalic acid) directly into soils in order to “engineer” the bacterial functions towards the control of diseases caused by R. solani.

Comparative genomics and trait evolution in Cleomaceae, a model family for ancient polyploidy
Bergh, Erik van den - \ 2017
Wageningen University. Promotor(en): M.E. Schranz; Y. van de Peer. - Wageningen : Wageningen University - ISBN 9789463431705 - 106
capparaceae - genomics - polyploidy - evolution - genomes - reproductive traits - flowers - colour - glucosinolates - genetic variation - biosystematics - taxonomy - identification - capparaceae - genomica - polyploïdie - evolutie - genomen - voortplantingskenmerken - bloemen - kleur - glucosinolaten - genetische variatie - biosystematiek - taxonomie - identificatie

As more and more species have been sequenced, evidence has been piling up for a fascinating phenomenon that seems to occur in all plant lineages: paleopolyploidy. Polyploidy has historically been a much observed and studied trait, but until recently it was assumed that polyploids were evolutionary dead-ends due to their sterility. However, many studies since the 1990’s have challenged this notion by finding evidence for ancient genome duplications in many genomes of current species. This lead to the observation that all seed plants share at least one ancestral polyploidy event. Another polyploidy event has been proven to lie at the base of all angiosperms, further signifying the notion that ancient polyploidy is widespread and common. These findings have led to questions regarding the apparent disadvantages that can be observed in a first generation polyploid. If these disadvantages can be overcome however, duplication of a genome also presents an enormous potential for evolutionary novelty. Duplicated copies of genes are able to acquire changes that can lead to specialization of the duplicated pair into two functions (subfunctionalization) or the development of one copy towards an entirely new function (neofunctionalization).

Currently, most research towards polyploidy has focused on the economically and scientifically important Brassicaceae family containing the model plant Arabidopsis thaliana and many crops such as cabbage, rapeseed, broccoli and turnip. In this thesis, I lay the foundations for the expansion of this scope to the Cleomaceae, a widespread cosmopolitan plant family and a sister family of Brassicaceae. The species within Cleomaceae are diverse and exhibit many scientifically interesting traits. They are also in a perfect position phylogenetically to draw comparisons with the much more studied Brassicaceae. I describe the Cleomaceae and their relevance to polyploid research in more detail in the Introduction. I then describe the important first step towards setting up the genetic framework of this family with the sequencing of Tarenaya hassleriana in Chapter 1.

In Chapter 2, I have studied the effects of polyploidy on the development of C4 photosynthesis by comparing the transcriptome of C3 photosynthesis based species Tarenaya hassleriana with the C4 based Gynandropsis gynandra. C4 photosynthesis is an elaboration of the more common C3 form of photosynthesis that concentrates CO2 in specific cells leading to decreased photorespiration by the RuBisCO and higher photosynthetic efficieny in low CO2 environments. I find that polyploidy has not led to sub- or neofunctionalization towards the development of this trait, but instead find evidence for another important phenomenon in postpolyploid evolution: the dosage balance hypothesis. This hypothesis states that genes which are dependent on specific dosage levels of their products will be maintained in duplicate; any change in their function would lead to dosage imbalance which would have deleterious effects on their pathway. We show that most genes involved in photosynthesis have returned to single copy in G. gynandra and that the changes leading to C4 have mostly taken place at the expression level confirming current assumptions on the development of this trait.

In Chapter 3, I have studied the effects of polyploidy on an important class of plant defence compounds: glucosinolates. These compounds, sometimes referred to as ‘mustard oils’, play an important role in the defence against herbivores and have radiated widely in Brassicaceae to form many different ‘flavors’ to deter specific herbivores. I show that in Cleomaceae many genes responsible for these compounds have benefited from the three rounds of polyploidy that T. hassleriana has undergone and that many duplicated genes have been retained. We also show that more than 75% is actively expressed in the plant, proving that the majority of these duplications has an active function in the plant.

Finally, in Chapter 4 I investigate a simple observation made during experiments with T. hassleriana in the greenhouse regarding the variation in flower colour between different individuals: some had pink flowers and some purple. Using LC-PDA mass spectrometry we find that the two colours are caused by different levels of two anthocyanin pigments, with cyanidin dominating in the purple flowers and pelargonidin being more abundant in pink flowers. Through sequence comparison and synteny analysis between A. thaliana and T. hassleriana we find the orthologs of the genes involved in this pathway. Using a Genotyping by Sequencing method on a cross between these two flower colours, we produce a collection of SNP markers on the reference genome. With these SNPs, we find two significant binary trait loci, one of which corresponds to the location of the F3’H ortholog which performs the conversion of a pelargonidin precursor to a cyanidin precursor.

In the General Conclusion, I combine all findings of the previous chapters and explain how they establish part of a larger species framework to study ancient polyploidy in angiosperms. I then put forth what these findings can mean for possible future research and the directions that are worth to be explored further.

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.

Guam Sponge Microbial OTU abundance & Taxonomy (Greengenes)
Steinert, G. ; Taylor, Michael W. ; Deines, Peter ; Simister, Rachel L. ; Voogd, Nicole J. De; Hoggard, Michael ; Schupp, Peter J. - \ 2016
OTU table - 16S rRNA - greengenes - taxonomy - sponges
16S rRNA gene OTU (97%) Greengenes classification and abundance table of sponge associated microbial communities from Guam (USA) - 2247 OTUs
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

THE MOUNTAIN VEGETATION OF SOUTH PERU: SYNTAXONOMY, ECOLOGY, PHYTOGEOGRAPHY AND CONSERVATION

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.

The Gilbertiodendron ogoouense species complex (Leguminosae : Caesalpinioideae), Central Africa
Burgt, X.M. van der; Mackinder, B.A. ; Wieringa, J.J. ; Estrella, Manuel de la - \ 2015
Kew Bulletin 70 (2015)2. - ISSN 0075-5974
Conservation - Macrolobium - new species - taxonomy

The Gilbertiodendron ogoouense species complex consists of 14 tree species. Eight species are here newly described and one is here reinstated: G. bambolense Burgt; G. breteleri Burgt; G. ebo Burgt & Mackinder; G. ecoukense (Pellegr.) Burgt; G. maximum Burgt & Wieringa; G. minkebense Burgt & Estrella; G. quinquejugum Burgt; G. scutatum Wieringa & Estrella and G. sulfureum Burgt. Five species in the complex were already recognised as accepted: G. brachystegioides (Harms) J. Léonard; G. klainei (Pierre ex Pellegr.) J. Léonard; G. newberyi Burgt; G. ngouniense (Pellegr.) J. Léonard and G. ogoouense (Pellegr.) J. Léonard. All 14 species are medium-sized or large trees of evergreen rain forest on well-drained or periodically inundated soil, at 0 – 900 m altitude. Each of the 14 species is distributed in one or more of the following Central African countries: Cameroon, Equatorial Guinea, Gabon, Congo (Brazzaville), Angola (Cabinda) and Congo (Kinshasa). Included are a key, a table comparing the main morphological characters, illustrations drawn to the same scale and distribution maps of all species. The conservation status of all species is assessed according to IUCN categories and criteria: G. maximum is classified as Critically Endangered, G. ebo and G. newberyi as Endangered, G. breteleri, G. klainei, G. minkebense, G. ngouniense and G. scutatum as Vulnerable, and the remaining six species as Least Concern.

Identifying and naming plant-pathogenic fungi: past, present, and future
Crous, P.W. ; Hawksworth, D.L. ; Wingfield, M.J. - \ 2015
Annual Review of Phytopathology 53 (2015). - ISSN 0066-4286 - p. 247 - 267.
molecular systematics - polyphyletic nature - polyphasic approach - mycorrhizal fungi - species concepts - taxonomy - genus - classification - identification - chromatography
Scientific names are crucial in communicating knowledge about fungi. In plant pathology, they link information regarding the biology, host range, distribution, and potential risk. Our understanding of fungal biodiversity and fungal systematics has undergone an exponential leap, incorporating genomics, web-based systems, and DNA data for rapid identification to link species to metadata. The impact of our ability to recognize hitherto unknown organisms on plant pathology and trade is enormous and continues to grow. Major challenges for phytomycology are intertwined with the Genera of Fungi project, which adds DNA barcodes to known biodiversity and corrects the application of old, established names via epi- or neotypification. Implementing the one fungus–one name system and linking names to validated type specimens, cultures, and reference sequences will provide the foundation on which the future of plant pathology and the communication of names of plant pathogens will rest.
Restyling Alternaria
Woudenberg, J.H.C. - \ 2015
Wageningen University. Promotor(en): Pedro Crous; Pierre de Wit, co-promotor(en): J.Z. Groenewald. - Wageningen : Wageningen University - ISBN 9789462574106 - 250
alternaria - taxonomie - fylogenie - moleculaire taxonomie - plantenziekteverwekkende schimmels - alternaria - taxonomy - phylogeny - molecular taxonomy - plant pathogenic fungi

The omnipresent dematiaceous hyphomycete genus Alternaria is associated with a wide variety of substrates including seeds, plants, agricultural products, humans, soil and even the atmosphere. It includes saprophytic, endophytic and pathogenic species, among which multiple plant pathogens, post-harvest pathogens, and human pathogens (causative agents of phaeohyphomycosis and hypersensitivity reactions). Molecular studies reveal that the Alternaria complex comprises nine genera. Within this complex several genera are non-monophyletic and Alternaria species cluster into multiple distinct species clades, which are not always correlated with species-groups based on morphological characteristics. The most commonly reported species in literature and type species of the genus Alternaria, A. alternata, also comprises one such species-group. The small-spored Alternaria species within this group are mainly described based on morphology and / or host-specificity, but are difficult to distinguish based on molecular techniques alone. As A. alternata is considered as one of the most prolific producers of fungal allergens and is reported as pathogen on over 100 host plants, correct species identification is of utmost importance. The research presented in this thesis discusses the taxonomic status of Alternaria and its related genera, with a further focus on the two biggest and most important species complexes; the large-spored A. porri and small-spored A. alternata species complexes. With the phylogenies and classifications presented in this thesis, more robust and understandable taxonomy and nomenclature in Alternaria and allied genera within the Alternaria complex are created.

Chapter 1 gives a general introduction to the genus Alternaria and related genera. The history of the genus and its economic importance as plant pathogen, post-harvest pathogen, causative agent of phaeohyphomycosis and common allergen causing hypersensitivity reactions are summarized. The introduction of the morphological species complexes, based on characters of the conidia, the pattern of chain formation, and the nature of the apical extensions of conidia are treated. Molecular studies recognise seven Alternaria species-groups within the Alternaria complex. Besides Alternaria, eight other genera are assigned to the Alternaria complex based on molecular and morphological studies.

Chapter 2 focusses on the relationship of Alternaria and its closely related genera within the broader Alternaria complex. The phylogenetic lineages within the Alternaria complex are delineated based on nucleotide sequence data of parts of the 18S nrDNA (SSU), 28S nrDNA (LSU), the internal transcribed spacer regions 1 and 2 and intervening 5.8S nrDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RNA polymerase second largest subunit (RPB2) and translation elongation factor 1-alpha (TEF1) gene regions. The phylogenetic data reveal a Stemphylium clade sister to Embellisia annulata and a big Alternaria clade. The Alternaria clade contains six monotypic lineages and 24 internal clades, which are treated as sections of Alternaria. In order to create a stable phylogenetic taxonomy, and supported by i) a well-supported phylogenetic node in multiple analyses, ii) a high-similarity of clades within Alternaria based on SSU, LSU and ITS data, and iii) variation in the clade order between the different gene phylogenies, 13 genera are placed into synonymy with Alternaria. Embellisia annulata is synonymized with Dendryphiella salina, and together with D. arenariae placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, with asexual forms linked to Alternaria, cluster within the Pleosporaceae, as does Alternaria, but outside Alternaria s. str. The genus Alternariaster, described to accommodate Alternaria helianthi, clusters within the Leptosphaeriaceae.

Chapter 3 describes the reappraisal of the genus Alternariaster. Alternaria helianthi, the causal agent of leaf spot on Helianthus annuus (sunflower) was segregated from Alternaria based on conidial morphology, and placed in the new genus Alternariaster. A multi-gene phylogeny of parts of the ITS, LSU, RPB2 and GAPDH gene regions placed a fungal pathogen associated with leaf spot on Bidens sulphurea (yellow cosmos) in Brazil in close relation with Al. helianthi. Based on the close phylogenetic relation to Al. helianthi, but distinct morphological and pathogenicity characters, the fungal pathogen associated with leaf spot on B. sulphurea is newly described as Al. bidentis.

Chapter 4 treats the Alternaria species which form the largest section of Alternaria, sect. Porri. This section contains almost all Alternaria species with medium to large conidia with long beaks, some of which are important plant pathogens. A multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alternaria major allergen (Alt a 1) gene regions, supplemented with morphological and cultural studies, forms the basis for species recognition in this section. The polyphasic data reveal 63 species in sect. Porri, of which 10 are newly described, and 27 names are synonymized.

Chapter 5 treats the small-spored Alternaria species, which reside in sect. Alternaria. A lot of confusion around the naming of species within this section exists, since the naming is mostly based on morphology and host-specificity, although the molecular variation is minimal. Whole genome sequencing, combined with transcriptome profiling and multi-gene sequencing of nine gene regions, SSU, LSU, ITS, GAPDH, RPB2, TEF1, Alt a 1, endopolygalacturonase (endoPG) and an anonymous gene region (OPA10-2), is used to create a clear and stable species classification in this section. The nine sequenced Alternaria genomes range in size from 32.0 - 39.1 Mb. The number of repetitive sequences varies significantly, with a relative low percentage of repeats within sect. Alternaria. The genome identity within sect. Alternaria is high, compared to the genome identity for isolates from other sections to the A. alternata reference genome. Similarly, a relative low percentage of single nucleotide polymorphisms (SNPs) were observed in genomic and transcriptomic sequences between isolates from sect. Alternaria, compared to the percentage of SNP’s found in isolates from different sections compared to the A. alternata reference genome. A set of core proteins was extracted from the genome and transcriptome data, and primers were designed on two eukaryotic orthologous group (KOG) protein loci with a relatively low degree of conservation within section Alternaria. The phylogenies from these two gene regions, KOG1058 and KOG1077, could not distinguish the described morphospecies within sect. Alternaria better than the phylogenies based on the nine commonly used gene regions for Alternaria. Based on genome and transcriptome comparisons and molecular phylogenies, Alternaria sect. Alternaria consists of only 11 phylogenetic species and one species complex. Thirty-five morphospecies are synonymized under A. alternata. The subclades that are formed by these isolates are incongruent between the different gene regions sequenced; no two genes show the same groupings for any of the over 100 isolates. A sequence-based identification guide is provided for the species which are now recognized in sect. Alternaria. None of the genes sequenced in this study can distinguish all of the species recognized here on its own.

Chapter 6 investigates the molecular diversity of indoor Alternaria isolates in the USA, with the help of a phylogeographic / population genetic approach. Isolates collected throughout the USA were identified using ITS, GAPDH and endoPG gene sequencing, followed by genotyping and population genetic inference of the sect. Alternaria isolates and 37 reference isolates, using five microsatellite markers. Phylogenetic analyses revealed that 98 % (153 isolates) of the indoor isolates consisted of species from Alternaria sect. Alternaria. The remaining 2 % (three isolates) represented one sect. Infectoriae and two sect. Pseudoulocladium isolates. From the 153 isolates that belonged to sect. Alternaria, one could be assigned to A. burnsii, 15 to the A. arborescens species complex and the remaining 137 isolates were identified as A. alternata. Based on the microsatellite data, no specific indoor population could be distinguished. Population assignment analyses of the A. alternata isolates suggested that subpopulations did not exist within the sample, which we thus divided into four artificial subpopulations to represent four quadrants of the USA. Genotypic diversity was extremely high for all quadrants and a test for linkage disequilibrium suggested that A. alternata has a cryptic sexual cycle. The SouthWest-USA population displayed the highest level of uniqueness, based on private alleles. Intriguingly, the highest amount of gene flow, between SouthWest-USA and SouthEast-USA, correlated with the west-to-east movement of the antitrade winds. This suggests that indoor A. alternata isolates, although extremely diverse, have a continental distribution and high levels of gene flow over the continent.

Chapter 7 discusses the data presented in this thesis. The implications of the performed studies are placed in a broader context, with a focus on the relation between morphology and the new species classification based on molecular tools and the use of genome data in contrast to multi-gene data.

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

Abstract

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.

Phylogeny and DNA-based identification in Phoma and related genera
Aveskamp, M.M. - \ 2014
Wageningen University. Promotor(en): Pedro Crous; Pierre de Wit. - Wageningen : Wageningen University - ISBN 9789461739148 - 206
phoma - fylogenie - taxonomie - moleculaire taxonomie - identificatie - verklarende woordenlijsten - phoma - phylogeny - taxonomy - molecular taxonomy - identification - glossaries
Species delimitation and DNA barcoding of Atlantic Ensis (Bivalvia, Pharidae)
Vierna, J. ; Cuperus, J. ; Martinez-lage, A. ; Jansen, J.M. ; Perina, A. ; Pelt-Heerschap, H.M.L. van; Gonzalez-Tizon, A.M. - \ 2014
Zoologica Scripta 43 (2014)2. - ISSN 0300-3256 - p. 161 - 171.
pcr-rflp analysis - phylogenetic networks - maximum-likelihood - mollusca-bivalvia - 5s rdna - siliqua - directus - macha - population - taxonomy
Ensis Schumacher, 1817 razor shells occur at both sides of the Atlantic and along the Pacific coasts of tropical west America, Peru, and Chile. Many of them are marketed in various regions. However, the absence of clear autapomorphies in the shell and the sympatric distributions of some species often prevent a correct identification of specimens. As a consequence, populations cannot be properly managed, and edible species are almost always mislabelled along the production chain. In this work, we studied whether the currently accepted Atlantic Ensis morphospecies are different evolutionary lineages, to clarify their taxonomic status and enable molecular identifications through DNA barcoding. For this, we studied 109 specimens sampled at 27 sites, which were identified as belonging to nine of those morphospecies. We analysed nucleotide variation at four nuclear (18S, 5.8S, ITS1, and ITS2) and two mitochondrial (COI and 16S) regions, although the 18S and 5.8S regions were not informative at the species level and were not further considered. The phylogenetic trees and networks obtained supported all morphospecies as separately evolving lineages. Phylogenetic trees recovered Ensis at each side of the Atlantic as reciprocally monophyletic. Remarkably, we confirm the co-occurrence of the morphologically similar E. minor (Chenu, 1843) and E. siliqua (Linné, 1758) along the NW Iberian coast, a fact that has been often overlooked. In South America, a relevant divergence between E. macha (Molina, 1792) individuals from Chile and Argentina was unveiled and suggests incipient speciation. We also confirm the occurrence of the North American species E. directus (Conrad, 1843) as far south as north-eastern Florida. Among the genomic regions analysed, we suggest COI as the most suitable DNA barcode for Atlantic Ensis. Our results will contribute to the conservation and management of Ensis populations and will enable reliable identifications of the edible species, even in the absence of the valves. The name Ensis coseli Vierna nom. nov. is proposed to replace E. minor Dall, 1899 non (Chenu, 1843).
Ontwikkelingen in naamgeving en registratie van cultuurplanten
Hoffman, M.H.A. - \ 2013
Dendroflora (2013)50. - ISSN 0374-7247 - p. 28 - 45.
houtachtige planten als sierplanten - boomkwekerijen - gewaskwaliteit - registratie - rassen (planten) - taxonomie - beschrijvingen - fruitgewassen - siergewassen - plantenveredeling - cultivars - handelsmerken - kwekersrecht - nomenclatuur - ornamental woody plants - forest nurseries - crop quality - registration - varieties - taxonomy - descriptions - fruit crops - ornamental crops - plant breeding - trade marks - breeders' rights - nomenclature
Een correcte en eenduidige naamgeving van onze boomkwekerijgewassen is van groot belang voor de groensector. Het is immers een belangrijk middel voor de garantie van soortechtheid en is daarmee een wezenlijk onderdeel van de plantkwaliteit. In dit artikel staan nieuwe ontwikkelingen weergegeven vanuit de wetenschap, de wetgever en het bedrijfsleven. Het bouwt voort op twee eerder geschreven artikelen in Dendroflora over naamgeving van planten (1999) en classificatie van planten (2008). In het eerste deel van dit artikel wordt een aantal items en ontwikkelingen uit enkele voorgaande artikelen genoemd en in een historisch perspectief gezet. In het tweede deel wordt ingegaan op de wettelijke registratie van plantenrassen. Vooral in de registratie van fruitrassen zijn er flinke veranderingen en daarnaast dreigen op termijn soortgelijke ontwikkelingen in de registratie van siergewassen. Dergelijke wetgeving heeft grote invloed op de teelt en handel van tuinbouwgewassen. In het derde deel wordt ingegaan op de ontwikkelingen in de naamgeving van cultuurplanten vanuit de wetenschap. Vorig jaar is een symposium geweest waarin veel zaken besproken en bediscussieerd zijn. Op basis hiervan wordt de regelgeving van de Cultuurplantencode (ICNCP) aangepast. Opgestelde regels of richtlijnen voor nieuwe categorieën zoals de grex, series en zaadmengsels en cultivartypes worden besproken. Tenslotte komen in het vierde deel enkele werkwijzen en voorbeelden uit de praktijk aan de orde. Voorbeelden zijn de intensivering van veredeling, de diversiteit en wildgroei in gebruik van handelsnamen, het niet vermelden van de cultivarnaam, het merkenrechtelijk beschermen van de cultivarnaam en het gebruik van diverse symbolen om verschillende types van bescherming aan te geven
Phytopathogenic Dothideomycetes
Crous, P.W. ; Verkley, G.J.M. ; Groenewald, J.Z. - \ 2013
Utrecht, The Netherlands : CBS-KNAW Fungal Biodiversity Centre (Studies in mycology 75) - ISBN 9789070351960 - 406
dothideomycetes - plantenziekteverwekkende schimmels - taxonomie - fylogenie - gastheerreeks - alternaria - cercospora - phoma - pseudocercospora - septoria - nieuwe soorten - nieuw geslacht - plant pathogenic fungi - taxonomy - phylogeny - host range - new species - new genus
This volume of Studies in Mycology is dedicated to the plant health officers of the world, who are constantly confronted by a range of plant pathogenic fungi that cause devastating diseases of agricultural and forestry crops. Five main groups of fungi are dealt with, namely Alternaria, Cercospora, Phoma, Pseudocercospora and Septoria. In the first paper Phoma sections Plenodomus, Heterospora and Pilosa were reinvestigated, resulting in the introduction of several novel genera and species. The second paper deals with the paraphyletic genus Pseudocercospora; host specificity was considered for 146 species of Pseudocercospora occurring on 115 host genera from 33 countries. From these results we concluded that the application of European and American names to Asian taxa, and vice versa, was often not warranted. The third paper deals with the genus Cercospora, which contains more than 5 000 different species. Isolates used in the molecular phylogeny were obtained from 161 host species, 49 host families and 39 countries. Although some species were found to host-specific, others were isolated from a wide host range. The fourth paper deals with phylogenetic lineages within the genus Alternaria, which was revealed to represent a well-supported node containing 24 internal clades and six monotypic lineages. Several genera were placed in synonymy with Alternaria, for which 16 new sections were proposed. Two papers deal with the genus Septoria, which was shown to be poly- and paraphyletic, leading to the introduction of 15 new genera, and more than 40 new species. Although some species were shown to be highly specific, other taxa were revealed to occur on hosts in more than six different plant families. For all taxa investigated multi-gene DNA data were deposited in GenBank and other databases to expedite future identification of these plant pathogenic fungi. No single locus was found to be the ideal DNA barcode gene for these taxa, and species identification will have to be based on a combination of gene loci and morphological characters.
Cultivation and diseases of Proteaceae: Leucadendron, Leucospermum and Protea
Crous, P.W. ; Denman, S. ; Taylor, J.E. ; Swart, L. ; Bezuidenhout, C.M. ; Hoffman, L. ; Palm, M.E. ; Groenewald, J.Z. - \ 2013
Utrecht, The Netherlands : CBS-KNAW Fungal Biodiversity Centre (CBS biodiversity series 13) - ISBN 9789070351953 - 360
proteaceae - leucadendron - leucospermum - protea - snijbloemen - teelt - plantenziekten - plantenziekteverwekkende schimmels - taxonomie - identificatie - determinatietabellen - gastheerreeks - plantenziekteverwekkende bacteriën - ziektebestrijding - fytosanitair beleid - verwelkingsziekten - wortelrot - kanker (plantenziektekundig) - cut flowers - cultivation - plant diseases - plant pathogenic fungi - taxonomy - identification - keys - host range - plant pathogenic bacteria - disease control - phytosanitary policies - wilts - root rots - cankers
Proteaceae represent a prominent family of flowering plants in the Southern Hemisphere. Because of their beauty, unique appearance, and relatively long shelf life, Proteaceae cut-flowers have become a highly desirable crop for the export market. The cultivation of Proteaceae is a thriving industry that provides employment in countries where these flowers are grown, often in areas that are otherwise unproductive agriculturally. Diseases cause a loss in yield, and also limit the export of these flowers due to strict phytosanitary regulations. In this publication the fungi that cause leaf, stem and root diseases on Leucadendron, Leucospermum and Protea are treated. Data are provided pertaining to the taxonomy, identification, host range, distribution, pathogenicity, molecular characteristics and control of these pathogens. Taxonomic descriptions and illustrations are provided and keys are included to distinguish species in genera where a number of species affect Proteaceae. Disease symptoms are described and colour photographs are included. Where known, factors that affect disease epidemiology are discussed. Disease management strategies are also presented that will assist growers and advisors in making appropriate choices for reducing disease in specific areas. Information is also provided relating to crop improvement, cultivation techniques, harvesting and export considerations. Further development and expansion of this industry depends on producing and obtaining disease-free germplasm from countries where these plants are indigenous. For that reason it is important to document the fungi that occur on Proteaceae, and to establish the distribution of these fungi. These data are essential for plant quarantine services for use in risk assessments.
Letter to the Editor : One Fungus, One Name: Defining the Genus Fusarium in a Scientifically Robust Way That Preserves Longstanding Use
Geiser, D.M. ; Aoki, T. ; Bacon, C.W. ; Baker, S.E. ; Bhattacharyya, M.K. ; Brandt, M.E. ; Brown, D.W. ; Burgess, L.W. ; Chulze, S. ; Coleman, J.J. ; Correll, J.C. ; Covert, S.F. ; Crous, P.W. ; Waalwijk, C. - \ 2013
Phytopathology 103 (2013). - ISSN 0031-949X - p. 400 - 408.
solani species complex - sudden-death syndrome - phylogeny - tucumaniae - taxonomy - reveals - genera
In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.
Alternaria redefined
Woudenberg, J.H.C. ; Groenewald, J.Z. ; Binder, M. ; Crous, P.W. - \ 2013
Studies in Mycology 75 (2013)1. - ISSN 0166-0616 - p. 171 - 212.
ribosomal dna - phylogenetic-relationships - species-group - ulocladium - embellisia - genus - identification - sequences - taxonomy - nuclear
Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always correlate to species-groups based on morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera based on nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and six monotypic lineages, the assemblage of which we recognise as Alternaria. This puts the genera Allewia, Brachycladium, Chalastospora, Chmelia, Crivellia, Embellisia, Lewia, Nimbya, Sinomyces, Teretispora, Ulocladium, Undifilum and Ybotromyces in synonymy with Alternaria. In this study, we treat the 24 internal clades in the Alternaria complex as sections, which is a continuation of a recent proposal for the taxonomic treatment of lineages in Alternaria. Embellisia annulata is synonymised with Dendryphiella salina, and together with Dendryphiella arenariae, are placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, which were previously associated with Alternaria, cluster within the Pleosporaceae, outside Alternaria s. str., whereas Alternariaster, a genus formerly seen as part of Alternaria, clusters within the Leptosphaeriaceae. Paradendryphiella is newly described, the generic circumscription of Alternaria is emended, and 32 new combinations and 10 new names are proposed. A further 10 names are resurrected, while descriptions are provided for 16 new Alternaria sections
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