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.

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    Data from: The origin of floral organ identity quartets
    Ruelens, Philip ; Zhang, Zhicheng ; Mourik, H. van; Maere, Steven ; Kaufmann, K. ; Geuten, Koen - \ 2017
    KU Leuven
    evolution - angiosperms - flower development - MADS-domain - ancestral sequence rteconstruction
    The origin of flowers has puzzled plant biologists ever since Darwin referred to their sudden appearance in the fossil record as an abominable mystery. Flowers are considered to be an assembly of protective, attractive and reproductive male and female leaf-like organs. Their origin cannot be understood by a morphological comparison to gymnosperms, their closest relatives, which develop separate male or female cones. Despite these morphological differences, gymnosperms and angiosperms possess a similar genetic toolbox consisting of phylogenetically related MADS-domain proteins. Using ancestral MADS-domain protein reconstruction, we trace the evolution of organ identity quartets along the stem lineage of crown angiosperms. We provide evidence that current floral quartets specifying male organ identity, which consist of four types of subunits, evolved from ancestral complexes of two types of subunits through gene duplication and integration of SEPALLATA proteins just before the origin of flowering plants. Our results suggest that protein interaction changes underlying this compositional shift were the result of a gradual and reversible evolutionary trajectory. Modelling shows that such compositional changes may have facilitated the evolution of the perfect, bisexual flower.
    Characterization of B chromosomes in Lilium hybrids through GISH and FISH
    Xie, S.L. ; Marasek-Ciolakowska, A. ; Ramanna, M.S. ; Arens, P.F.P. ; Visser, R.G.F. ; Tuyl, J.M. van - \ 2014
    Plant Systematics and Evolution 300 (2014)8. - ISSN 0378-2697 - p. 1771 - 1777.
    ribosomal-rna genes - in-situ hybridization - nuclear-dna amounts - plants - angiosperms - probe - recombination - isochromosome - misdivision - longiflorum
    Supernumerary (B) chromosomes and small aberrant chromosomes were detected in Lilium hybrids and characterized through genomic in situ hybridization (GISH) and florescence in situ hybridization (FISH). Two small, supernumerary or B chromosomes were detected as extra chromosomes in a tetraploid plant derived from chromosome doubling of a hybrid (2n = 2x = 24) between a cultivar of the Longiflorum (L) and the Trumpet (T) group. When this tetraploid LLTT hybrid was crossed with a triploid LLO hybrid (O = Oriental), the B chromosome was transmitted to 73.4 % of the progenies. Based on GISH and FISH characterization, it was shown that the B chromosome consisted of two identical arms, with 5S rDNA hybridizing to the majority of it, which were flanked by normal telomeres, suggesting that this is an isochromosome. In another population, which is a backcross progeny between a F1 hybrid of Longiflorum x Asiatic (LA) and its Asiatic parent, the former produced functional 2n gametes which resulted in a triploid LAA progeny (2n = 3x = 36), in which three exceptional plants possessed 35 normal chromosomes and a small aberrant chromosome instead of the expected normal number of 36. In all three cases, the small aberrant chromosomes were isochromosomes which had obviously originated during the first backcross generation. These three chromosomes showed normal telomeres and mitosis. In addition, one of the new generated chromosomes possessed two 45S rDNA sites in the proximal positions. These new arisen isochromosomes were proposed to originate from centric breakage and fusion of two short arms of the missing chromosome in three genotypes, respectively, based on the comparison of arm lengths as well as rDNA loci. Their relevance to the origin of Bs is discussed.
    Phylogenetic lineages in the Botryosphaeriales: A systematic and evolutionary framework
    Slippers, B. ; Boissin, E. ; Phillips, A.J.L. ; Groenewald, J.Z. ; Wingfield, M.J. ; Postma, A. ; Burgess, T. ; Crous, P.W. - \ 2013
    Studies in Mycology 76 (2013)1. - ISSN 0166-0616 - p. 31 - 49.
    multiple gene genealogies - ribis species complex - combining data - south-africa - fungi - incongruence - proteaceae - origin - angiosperms - characters
    The order Botryosphaeriales represents several ecologically diverse fungal families that are commonly isolated as endophytes or pathogens from various woody hosts. The taxonomy of members of this order has been strongly influenced by sequence-based phylogenetics, and the abandonment of dual nomenclature. In this study, the phylogenetic relationships of the genera known from culture are evaluated based on DNA sequence data for six loci (SSU, LSU, ITS, EF1, BT, mtSSU). The results make it possible to recognise a total of six families. Other than the Botryosphaeriaceae (17 genera), Phyllostictaceae (Phyllosticta) and Planistromellaceae (Kellermania), newly introduced families include Aplosporellaceae (Aplosporella and Bagnisiella), Melanopsaceae (Melanops), and Saccharataceae (Saccharata). Furthermore, the evolution of morphological characters in the Botryosphaeriaceae were investigated via analysis of phylogeny-trait association. None of the traits presented a significant phylogenetic signal, suggesting that conidial and ascospore pigmentation, septation and appendages evolved more than once in the family. Molecular clock dating on radiations within the Botryosphaeriales based on estimated mutation rates of the rDNA SSU locus, suggests that the order originated in the Cretaceous period around 103 (45-188) mya, with most of the diversification in the Tertiary period. This coincides with important periods of radiation and spread of the main group of plants that these fungi infect, namely woody Angiosperms. The resulting host-associations and distribution could have influenced the diversification of these fungi.
    On the origin and evolution of apomixis in Boechera
    Lovell, J.T. ; Aliyu, O.M. ; Mau, M. ; Schranz, M.E. ; Koch, M. ; Kiefer, C. ; Song, B.H. ; Mitchell-Olds, T. ; Sharbel, T.F. - \ 2013
    Plant Reproduction 26 (2013)4. - ISSN 2194-7953 - p. 309 - 315.
    north-american boechera - genus boechera - holboellii brassicaceae - asexual reproduction - arabis-drummondii - hybridization - arabidopsis - angiosperms - expression - reappraisal
    The genetic mechanisms causing seed development by gametophytic apomixis in plants are predominantly unknown. As apomixis is consistently associated with hybridity and polyploidy, these confounding factors may either (a) be the underlying mechanism for the expression of apomixis, or (b) obscure the genetic factors which cause apomixis. To distinguish between these hypotheses, we analyzed the population genetic patterns of diploid and triploid apomictic lineages and their sexual progenitors in the genus Boechera (Brassicaceae). We find that while triploid apomixis is associated with hybridization, the majority of diploid apomictic lineages are likely the product of intra-specific crosses. We then show that these diploid apomicts are more likely to sire triploid apomictic lineages than conspecific sexuals. Combined with flow cytometric seed screen phenotyping for male and female components of apomixis, our analyses demonstrate that hybridization is an indirect correlate of apomixis in Boechera.
    Morphological character evolution of Amorphophallus (Araceae) based on a combined phylogenetic analysis of trnL, rbcL, and LEAFY second intron sequences
    Sedayu, A. ; Eurlings, M.C.M. ; Gravendeel, B. ; Hetterscheid, W.L.A. - \ 2010
    Botanical Studies 51 (2010)4. - ISSN 1817-406X - p. 473 - 490.
    chloroplast dna - gene - angiosperms - utility - regions - origin - family - matk
    Sequences of three different genes in 69 taxa of Amorphophallus were combined to reconstruct the molecular phylogeny of this species-rich Aroid genus. The data set was analyzed by three different methods, Maximum Parsimony, Maximum Likelihood and Bayesian analysis, producing slightly different tree topologies. Three major clades identified in all analyses reflect the biogeographical distribution of Amorphophallus. Some clades were supported by morphological characters such as sessile/nonsessile stigma, pollen opening mechanism, shape of the main segments of the lamina, growth cycle, and berry colour. When optimised, a nonsessile stigma may have evolved from a sessile one with several reversals. Pollen opening by connective rupturing evolved from pollen opening by pores. Unequally shaped segments of the lamina evolved from equally shaped segments. Simultaneously existing leaf and inflorescences evolved from alternating leaves and inflorescences. Blue, purple, green, and yellow berries evolved from red/orange/white ones.
    Phylogenetworks : exploring reticulate evolution and its consequences for phylogenetic reconstruction
    Vriesendorp, B. - \ 2007
    Wageningen University. Promotor(en): Marc Sosef, co-promotor(en): Freek Bakker; Ronald van den Berg. - [S.l.] : S.n. - ISBN 9789085047032 - 180
    fylogenetica - evolutie - taxonomie - hybridisatie - bedektzadigen - terminologie - phylogenetics - evolution - taxonomy - hybridization - angiosperms - terminology
    Minerals are essential for humans, plants and animals and have an important micronutrient role in physiological and metabolic processes of plants. Next to this essential role of minerals, they can also be very toxic when available to the plant in elevated amounts. Plants therefore need to keep very tight control over the intracellular mineral concentrations in a process called metal homeostasis. Although the metal homeostasis mechanisms are supposed to be universal within plants, there are plant species that can tolerate and even accumulate large amounts of metals without any sign of toxicity. Thlaspi caerulescens J. & C. Presl (Brassicaceae), a close relative of the plant reference species Arabidopsis thaliana (Arabidopsis), is one of these natural metal hyperaccumulator species. The overall aim of this project is to unravel the molecular genetic mechanism of heavy metal tolerance and hyperaccumulation of the metal hyperaccumulating plant species T. caerulescens. To achieve this goal heterologous transcript profiling experiments were performed, which involved comparative microarray hybridization experiments of the hyperaccumulator T. caerulescens and Arabidopsis. Arabidopsis is used as the reference species for heterologous transcript profiling because of the availability of genetic resources and the complete genome sequence. The micronutrient zinc has an essential role in physiological and metabolic processes in plants as a cofactor or structural element. Thlaspi caerulescens can accumulate up to 3% of zinc on a dry weight basis without any sign of toxicity. The question postulated here is if this has drastic effects on the zinc homeostasis mechanism. We examined in detail the transcription profiles of roots of Arabidopsis and T. caerulescens plants grown under deficient, sufficient and excess supply of zinc (Chapter 2). A total of 608 genes were detected in Arabidopsis and 352 in T. caerulescens that responded transcriptionally to changes in zinc supply. Only 14% of these genes were also zinc-responsive in Arabidopsis. When comparing Arabidopsis and T. caerulescens at comparable zinc exposures, over 2200 genes were significantly differentially expressed. While a large fraction of these genes are of yet unknown function, many genes with a different expression between Arabidopsis and T. caerulescens appear to function in metal homeostasis, in abiotic stress response and in lignin biosynthesis. The high expression of lignin biosynthesis genes corresponds to the deposition of lignin in the endodermis. Contrary to Arabidopsis roots, which have one endodermal cell layer, we found there are two endodermal layers in T. caerulescens roots. This extra physical barrier could enhance the control of metal fluxes in the plant, in addition to the higher expression of metal transporters in the root. Cadmium is a widespread, naturally occurring non-essential element that is toxic for plants in higher concentrations. In chapter 3 we compare between and within species transcript profiles of Arabidopsis and T. caerulescens roots exposed to cadmium, with the aim to establish which genes are most likely to be relevant for the tolerance to cadmium exposure of T. caerulescens. The comparative transcriptional analysis of the cadmium response of roots of the T. caerulescens and Arabidopsis emphasizes the role of genes involved in lignin-, glutathione- and sulfate metabolism. Furthermore two transcription factors, MYB72 and bHLH100, with an altered expression after exposure to cadmium, are studied for their involvement in metal homeostasis. Analysis of a myb72 knock-out mutant showed enhanced sensitivity to excess zinc or iron deficiency. Rather than controlling Cd tolerance, this gene appears to be involved in iron homeostasis, affecting the response to Cd indirectly. Arabidopsis transformants overexpressing the transcription factor bHLH100 showed enhanced zinc and nickel tolerance, and although the exact role of this gene still needs to be resolved, the genes appears to have a role in metal homeostasis in Arabidopsis. T. caerulescens accessions exhibit distinct metal accumulation, translocation and tolerance characteristics. T. caerulescens accession Ganges can accumulate high amounts of cadmium and is extremely tolerant to cadmium, whereas the La Calamine accession is also tolerant to cadmium but accumulates much less cadmium compared to Ganges. The transcription profiles of leaves and roots of T. caerulescens accessions Ganges and La Calamine plants grown with and without cadmium were examined using the Qiagen-Operon Arabidopsis Genome Array and results are described in chapter 4. A total of 161 genes were differentially expressed between the two T. caerulescens accessions in response to changes in cadmium supply and 38 genes were differentially expressed in T. caerulescens accession Ganges leaves in response to cadmium. The comparative transcriptional analysis emphasizes that there are just minor differences between the two accessions but the genes which are differentially expressed could play an important role in the hyperaccumulation of cadmium in Ganges. The microarray data suggest that especially genes involved in cell wall modification and stress response relate to the major difference between the two accessions in cadmium hyperaccumulation. Plants have evolved a complex network of homeostatic mechanisms that serve to control the uptake, accumulation, trafficking and detoxification of metals. One potential mechanism for heavy metal detoxification in plants is the chelation of metal ions to ligands like organic acids, amino acids, peptides and polypeptides. This mechanism is important for the distribution of metal ions by keeping metal ions mobile within the plant. In plants metals are often found to be chelated to nicotianamine. Nicotianamine is formed by trimerization of S-adenosylmethionine, which is catalyzed by the enzyme nicotianamine synthase. Arabidopsis contains four nicotianamine synthase (NAS) genes. Also in T. caerulescens four full-length cDNAs encoding nicotianamine synthase members were identified (Chapter 5). The four genes were named TcNAS1-TcNAS4, analogous to the corresponding closest homologue in Arabidopsis. Arabidopsis plants over-expressing TcNAS1, TcNAS2, TcNAS3 or TcNAS4 that were tested for their response to growth on media with different zinc, iron, nickel or cadmium supply, provided evidence that the Thlaspi genes all have a genuine NAS function because they complement the NAS deficiency in specific triple knock-out Arabidopsis mutants. Evidence for a functional role in metal homeostasis was sought in studying the Arabidopsis single, double, triple and a quadruple nicotianamine synthase T-DNA insertion mutants. The combination of null mutations in three or four AtNAS genes, results in a severe phenotype that includes interveinal chlorosis and altered metal concentrations in leaves, roots and seeds. Arabidopsis transformants overexpressing TcNAS3 or TcNAS4 showed enhanced zinc and nickel tolerance compared to wild type plants. The research described in this thesis does contribute to a better understanding of heavy metal hyperaccumulation in T. caerulescens and it can be concluded that it seems unlikely that altered regulation and overexpression of single genes will be sufficient to convert metal nonaccumulators into hyperaccumulators. However, the possibility that overexpression of one or two key regulatory loci have this effect remains.
    'Andean-centred' genera in the short-branch clade of Annonaceae: testing biogeographical hypotheses using phylogeny reconstruction and molecular dating
    Pirie, M.D. ; Chatrou, L.W. ; Mols, J.B. ; Erkens, R.H.J. ; Oosterhof, J. - \ 2006
    Journal of Biogeography 33 (2006)1. - ISSN 0305-0270 - p. 31 - 46.
    dna-sequences - historical biogeography - divergence times - plastid rbcl - rain-forest - data sets - evolution - fossil - angiosperms - diversity
    Aim We test biogeographical hypotheses regarding the origin of Andean-centred plant groups by reconstructing phylogeny in the short-branch clade (SBC) of Annonaceae, and estimating the timing of diversifications in four apparently Andean-centred genera: Cremastosperma R.E.Fr., Klarobelia Chatrou, Malmea R.E.Fr. and Mosannona Chatrou. The SBC includes species distributed in both the Old and New World tropics. A number of the Neotropical genera display 'Andean-centred' distribution patterns, with high species richness on both sides of the Andes mountain range. In particular, we test whether these groups could have originated on the South American continent during the time frame of the Andean orogeny [from c. 23 Ma (Miocene) to the present]. Methods Chloroplast DNA sequences were used to reconstruct phylogeny in related Annonaceae taxa plus outgroups, under maximum parsimony and Bayesian inference. The markers rbcL, trnL-trnF and psbA-trnH were sampled for 96 accessions to test the monophyly of each of the genera, and thus whether they might be para- or polyphyletic with respect to related groups distributed across Amazonia. To determine the sister groups of the four genera, the additional markers matK, ndhF, trnT-trnL, trnS-trnG and atpB-rbcL were sampled for 23 of the 96 accessions. Molecular dating techniques (nonparametric rate-smoothing; penalized likelihood; Bayesian inference) were then applied to estimate the age of the crown group of each genus and the age of their sister groups. Results Monophyly was confirmed in Cremastosperma, Malmea and Mosannona. The monotypic genus Pseudephedranthus Aristeg. was found to be nested within Klarobelia, the species of which otherwise formed a monophyletic group, and a South American-centred (SAC) clade was identified. The SAC clade comprises all the SBC genera distributed in South America and generally to a limited extent into Central America, but not those endemic to Africa, Asia and Central America. Age estimations for clades within the SBC were no older than around 60 Myr; those for the crown groups of Cremastosperma, Klarobelia, Malmea and Mosannona fell largely within the last 10–20 Myr. Main conclusions The distribution patterns of Cremastosperma, Klarobelia, Malmea and Mosannona are not the arbitrary result of the definition of para- or polyphyletic groups. We infer the presence of a common ancestor of the four genera in South America, but not by vicariance of an ancestral population on Gondwana. The age estimations, instead, may suggest that the SAC clade originated in South America by dispersal across the Boreotropics. Although the strength of this test was limited by imprecision in the molecular dating results, the ages of crown groups of the four genera suggest that diversifications occurred within the time frame of the orogeny of the Northern Andes
    Progenies of allotriploids of Oriental x Asiatic lilies (Lilium) examined by GISH analysis
    Barba Gonzalez, R. ; Silfhout, A.A. van; Visser, R.G.F. ; Ramanna, M.S. ; Tuyl, J.M. van - \ 2006
    Euphytica 151 (2006)2. - ISSN 0014-2336 - p. 243 - 250.
    nuclear-dna amounts - lily hybrids - crosses - recombination - culture - angiosperms - narcissus - liliaceae
    With the aim of utilizing allotriploid (2n = 3x = 36) lily hybrids (Lilium) in introgression breeding, different types of crosses were made. First, using diploid Asiatic lilies (2n = 2x = 24), reciprocal crosses (3x ¿ 2x and 2x ¿ 3x) were made with allotriploid hybrids (AOA) obtained by backcrosses of F1 Oriental × Asiatic hybrids (OA) to Asiatic cultivars (A). Secondly, the AOA allotriploids were crossed with allotetraploid (OAOA, 2n = 4x = 48), in 3x ¿ 4x combination. Finally, the AOA allotriploids where crossed to 2n gamete producer F1 OA hybrids (3x ¿ 2x (2n)). Two types of triploids were used as parents in the different types of crosses, derived from: (a) mitotic polyploidization and (b) sexual polyploidization. Ploidy level of the progeny was determined by estimating the DNA values through flowcytometry as well as chromosome counting. The aneuploid progeny plants from 3x ¿ 2x and reciprocal crosses had approximate diploid levels and in 3x ¿ 4x crosses and 3x ¿ 2x (2n) the progeny had approximate tetraploid levels. Balanced euploid gametes (x, 2x and 3x) were formed in the AOA genotypes. Recombinant chromosomes were found in the progenies of all crosses, except in the case of 2x ¿ 3x crosses through genomic in situ hybridization (GISH) analyses. Recombinant chromosomes occurred in the F1 OA hybrid when the triploid AOA hybrid was derived through sexual polyploidization, but not through mitotic polyploidization with two exceptions. Those recombinant chromosomes were transmitted to the progenies in variable frequencies.
    Description of Pratylenchus dunensis sp. n. (Nematoda: Pratylenchidae), a root-lesion nematode associated with the dune grass Ammophila arenaria (L.) Link
    Peña, E. de la; Moens, M. ; Aelst, A.C. van; Karssen, G. - \ 2006
    Nematology 8 (2006)1. - ISSN 1388-5545 - p. 79 - 88.
    dutch coastal foredunes - molecular characterization - knot nematode - competition - descriptions - morphology - morphometrics - new species - plant pests - ribosomal DNA - wild relatives - Ammophila arenaria - Elymus farctus - Pratylenchus - Ammophila - Poaceae - Cyperales - monocotyledons - angiosperms - Spermatophyta - plants - eukaryotes - Elymus - invertebrates - animals - Pratylenchidae - nucleotide sequences - plant parasitic nematodes - nematoda - restriction fragment length polymorphism - intergenic DNA - taxonomy - beschrijvingen - morfologie - morfometrie - nieuwe soorten - plantenplagen - ribosomaal DNA - wilde verwanten - Ammophila arenaria - Elymus farctus - Pratylenchus - Ammophila - Poaceae - Cyperales - eenzaadlobbigen - bedektzadigen - Spermatophyta - planten - eukaryoten - Elymus - ongewervelde dieren - dieren - Pratylenchidae - nucleotidenvolgordes - plantenparasitaire nematoden - Nematoda - restrictiefragmentlengtepolymorfisme - intergeen DNA - taxonomie
    A root-lesion nematode, Pratylenchus dunensis sp. n., is described and illustrated from Ammophila arenaria (L.) Link, a grass occurring abundantly in coastal dunes of Atlantic Europe. The new species is characterised by medium sized (454-579 ¿ m) slender, vermiform, females and males having two lip annuli (sometimes three to four; incomplete incisures only visible with scanning electron microscopy), medium to robust stylet (ca 16 ¿ m) with robust stylet knobs slightly set off, long pharyngeal glands (ca 42 ¿ m), lateral field with four parallel, non-equidistant, lines, the middle ridge being narrower than the outer ones, lateral field with partial areolation and lines converging posterior to the phasmid which is located between the two inner lines of the lateral field in the posterior half of the tail, round spermatheca filled with round sperm, vulva at 78% of total body length and with protruding vulval lips, posterior uterine sac relatively short (ca 19 ¿ m), cylindrical tail (ca 33 ¿ m) narrowing in the posterior third with smooth tail tip and with conspicuous hyaline part (ca 2 ¿ m). Males occur abundantly and present similar characteristics except for smaller dimensions for all morphological characters, but the head region is more truncated in outline than the female, spicule length is ca 15 ¿ m and testis length is ca 195 ¿ m. Nucleotide sequences of the rDNA expansion region D2D3 differed from the morphologically similar species P. penetrans and P. brzeskii that also occur in coastal dunes. These differences are supported by PCR-RFLP of the ITS-rDNA. Pratylenchus dunensis sp. n. was also found parasitising roots of Elymus farctus Viv.
    Morphological, molecular, and differential-host characterization of Meloidogyne floridensis n. sp (Nematoda : Meloidogynidae), a root-knot nematode parasitizing peach in Florida
    Handoo, Z.A. ; Nyczepir, A.P. ; Esmenjaud, D. ; Beek, J.G. van; Castagnone-Sereno, P. ; Carta, L.K. ; Skantar, A.M. ; Higgins, J.A. - \ 2004
    Journal of Nematology 36 (2004)1. - ISSN 0022-300X - p. 20 - 35.
    myrobalan plum - enzyme phenotypes - perineal patterns - prunus-cerasifera - resistance - heteroderidae - rootstock - identification - polymorphism - javanica - descriptions - host range - hosts - morphology - morphotaxonomy - new species - parthenogenesis - peaches - plant pests - Meloidogyne - Meloidogyne arenaria - Meloidogyne chitwoodi - Meloidogyne fallax - Meloidogyne floridensis - Meloidogyne graminicola - Meloidogyne hapla - Meloidogyne incognita - Meloidogyne javanica - Prunus persica - Florida - Meloidogynidae - invertebrates - animals - eukaryotes - Prunus - Rosaceae - Rosales - dicotyledons - angiosperms - Spermatophyta - plants - Gulf States of USA - Southern States of USA - APEC countries - Developed Countries - North America - America - OECD Countries - South Atlantic States of USA - Southeastern States of USA - animal anatomy - nucleotide sequences - plant parasitic nematodes - nematoda - host parasite relationships - random amplified polymorphic DNA - taxonomy - USA - beschrijvingen - gastheerreeks - gastheren (dieren, mensen, planten) - morfologie - morfotaxonomie - nieuwe soorten - parthenogenese - perziken - plantenplagen - Meloidogyne - Meloidogyne arenaria - Meloidogyne chitwoodi - Meloidogyne fallax - Meloidogyne floridensis - Meloidogyne graminicola - Meloidogyne hapla - Meloidogyne incognita - Meloidogyne javanica - Prunus persica - Florida - Meloidogynidae - ongewervelde dieren - dieren - eukaryoten - Prunus - Rosaceae - Rosales - tweezaadlobbigen - bedektzadigen - Spermatophyta - planten - golfstaten van de VS - zuidelijke staten van de VS - APEC-landen - ontwikkelde landen - Noord-Amerika - Amerika - OESO-landen - zuid-Atlantische staten van de VS - zuidoostelijke staten van de VS - dieranatomie - nucleotidenvolgordes - plantenparasitaire nematoden - Nematoda - gastheer parasiet relaties - random amplified polymorphic DNA - taxonomie - VS
    A root-knot nematode, Meloidogyne floridensis n. sp., is described and illustrated from peach originally collected from Gainesville, Florida. This new species resembles M. incognita, M. christiei, M. graminicola, and M. hispanica, but with LM and SEM observations it differs from these species either by the body length, shape of head, tail and tail terminus of second-stage juveniles, body length and shape of spicules in males, and its distinctive female perineal pattern. This pattern has a high to narrowly rounded arch with coarsely broken and network-like striae in and around anal area, faint lateral lines interrupting transverse striae, a sunken vulva and anus, and large distinct phasmids. Molecular data from ribosomal IGS illustrate that M. floridensis n. sp. is different from the mitotic species M. arenaria, M. incognita, and M. javanica. Data from RAPDs confirm it and suggest that this new species lies in an intermediate phylogenetic position between the previous species and the meiotic species M. hapla, M. fallax, and M. chitwoodi. Differential host tests based on annual crops and on Prunus accessions are reported.
    Myristicineae, a new suborder within Magnoliales
    Chatrou, L.W. - \ 2003
    Taxon 52 (2003)2. - ISSN 0040-0262 - p. 277 - 279.
    phylogenetic analysis - molecular-data - angiosperms - sequences - rbcl - classification - mitochondrial - annonaceae - genomes - plants
    Myristicaceae are sister group to the remaining five families of Magnoliales, which make up the suborder Magnoliineae. Both with regard to morphological and DNA sequence data, Myristicaceae have diverged substantially from Magnoliineae, whereas at the same time monophyly of Magnoliales is conclusive. This relationship between Myristicaceae and Magnoliineae is affirmed by describing the suborder Myristicineae.
    Ovules, megagametophytes and embryos. Ultrastructural studies after cryofixation
    Thijssen, M.H. - \ 2003
    Wageningen University. Promotor(en): J.L. van Went, co-promotor(en): Anne Mie Emons. - [S.l.] : S.n. - ISBN 9789058088826
    planten - bedektzadigen - brassica - petunia - onbevruchte eitjes - cryopreservering - plantenembryo's - celultrastructuur - biologische technieken - plants - angiosperms - brassica - petunia - ovules - cryopreservation - plant embryos - cell ultrastructure - biological techniques
    Karyotype analysis of Lilium longiflorum and Lilium rubellum by chromosome banding and fluorescence in situ hybridisation
    Lim, K.B. ; Wennekes, J. ; Jong, J.H.S.G.M. de; Jacobsen, E. ; Tuyl, J.M. van - \ 2001
    Genome 44 (2001)5. - ISSN 0831-2796 - p. 911 - 918.
    ribosomal-rna genes - nuclear-dna amounts - sequence - barley - genome - hybridization - wheat - organization - angiosperms - regions
    Detailed karyotypes of Lilium longiflorum and L. rubellum were constructed on the basis of chromosome arm lengths, C-banding, AgNO3 staining, and PI-DAPI banding, together with fluorescence in situ hybridisation (FISH) with the 5S and 45S rDNA sequences as probes. The C-banding patterns that were obtained with the standard BSG technique revealed only few minor bands on heterologous positions of the L. longiflorum and L. rubellum chromosomes. FISH of the 5S and 45S rDNA probes on L. longiflorum metaphase complements showed overlapping signals at proximal positions of the short arms of chromosomes 4 and 7, a single 5S rDNA signal on the secondary constriction of chromosome 3, and one 45S rDNA signal adjacent to the 5S rDNA signal on the subdistal part of the long arm of chromosome 3. In L. rubellum, we observed co-localisation of the 5S and 45S rDNA sequences on the short arm of chromosomes 2 and 4 and on the long arms of chromosomes 2 and 3, and two adjacent bands on chromosome 12. Silver staining (Ag-NOR) of the nucleoli and NORs in L. longiflorum and L. rubellum yielded a highly variable number of signals in interphase nuclei and only a few faint silver deposits on the NORs of mitotic metaphase chromosomes. In preparations stained with PI and DAPI, we observed both red- and blue-fluorescing bands at different positions on the L. longiflorum and L. rubellum chromosomes. The red-fluorescing or so-called reverse PI-DAPI bands always coincided with rDNA sites, whereas the blue-fluorescing DAPI bands corresponded to C-bands. Based on these techniques, we could identify most of chromosomes of the L. longiflorum and L. rubellum karyotypes.
    Plant Resources of South-East Asia No. 11. Auxiliary plants
    Jansen, P.C.M. ; Oyen, L.P.A. ; Maesen, L.J.G. van der - \ 1997
    Leiden : Backhuys Publishers (Plant Resources of South-East Asia 11) - ISBN 9789073348660 - 389
    wilde planten - bedektzadigen - bosbouw - bomen - beplantingen - zuidoost-azië - dekgewassen - bosproducten anders dan hout - economische botanie - wild plants - angiosperms - forestry - trees - plantations - south east asia - cover crops - non-wood forest products - economic botany
    Legumes traditionnels du Cameroun, une etude agro-botanique
    Stevels, J.M.C. - \ 1990
    Agricultural University. Promotor(en): L.J.G. van der Maesen; M. Flach, co-promotor(en): F.J. Breteler. - Wageningen : Agricultural University - ISBN 9789067541510 - 262
    bedektzadigen - wilde planten - tuinieren - groenteteelt - sierplanten - kameroen - plantkunde - economische botanie - angiosperms - wild plants - gardening - vegetable growing - ornamental plants - cameroon - botany - economic botany

    Cameroon has a remarkable abundance of vegetable species. A great variety of local and introduced vegetable crops are grown and together with a significant number of wild and semi-wild plants, occasionally cultivated, form a valuable complementary food in the daily diet.

    Primarily the aim of this study is to present an inventory of traditional vegetable species in Cameroon, indicating their importance in local agriculture, their significance as food and their nutritional value. The second objective is a taxonomical study of these vegetable crops, in order to expose, and where feasible eliminate, the existing widespread confusion in their scientific nomenclature. Botanical descriptions and practical differential keys, based on those parts of the plants that are actually used, are provided. This study deals with 67 traditional vegetables, 20 species of which are discussed in greater detail. The materials and data were gathered mainly in Cameroon during the period 1975 - 1979, and subsequently elaborated upon at the Department of Plant Taxonomy of the Agricultural University, Wageningen, The Netherlands.

    Chapter I contains a general introduction. The working plan (chapter 2) clarifies the selection of the 20 primary species (paragraph 2.1). Further detailed information is supplied regarding the materials used and the applied methods of investigation (paragraph 2.2).

    Chapter 3 presents the five agro-ecological regions into which Cameroon can be divided (paragraph 3. 1). A review is given of the physical and biological environment (paragraph 3.2) and of the agriculture and animal husbandry (paragraph 3.3). Various aspects pertaining to vegetables are discussed, such as the different types of vegetable crops (paragraph 3.4. 1), local and introduced vegetables (paragraph 3.4.2), the inventory of the vegetables in the different agro- ecological regions (paragraph 3.4.3) and a classification of wild and/or cultivated species (paragraph 3.4.4). Finally the various types of vegetable production are dealt with (paragraph 3.5).

    Chapter 4 is based on nutritional research and surveys which have been carried out in Cameroon since 1953. The first part is devoted to a survey of food and nutrition in the different agro-ecological regions (paragraph 4. 1). In the second part an account is given of the preparation and utilisation of vegetables including their nutritional value (paragraph 4.2).

    Chapter 5 deals with the botanical study of the vegetable species. Differential keys to groups of species (paragraph 5. 1. 1) and to individual species (paragraph 5.1.2), based on characteristics of the edible product, are supplied. In the next paragraph (5.2) all 67 species are arranged in alphabetical order, primarily in family order and subsequently according to the genera and species. This paragraph also provides concise information concerning the 47 secondary species.

    The 20 primary species are considered in a final paragraph (5.3), also in alphabetical order.
    The format of the text in the paragraphs 5.2 and 5.3 is essentially similar for each species. In paragraph 5.2 the author and the original publication of the species are cited, along with the current synonyms, pertinent literature, vernacular names, the occurrence in each of the five agro-ecological regions, a concise botanical description, a few relevant notes, representative herbarium specimens from Cameroon and finally the applicability as a vegetable. Furthermore paragraph 5.3 provides an etymological explanation of the scientific name and the typification, while synonymy, literature, geographic distribution and botanical description are discussed at length. Notes in this paragraph elaborate the typification. Any other relevant questions are subsequently dealt with, such as the recurring confusion with other species of the same genus, infraspecific variation and the distinction of cultivar-groups or cultivars, some cytogenetic and evolutionary aspects, and the use as a vegetable. Finally all the herbarium material examined from Cameroon is listed.

    Each species is accompanied by a botanical drawing of the edible parts of the plant in paragraph 5.2. Species dealt with in paragraph 5.3 are fully illustrated. In some cases a photograph is added. In conclusion a general bibliography and indices of scientific and vernacular plant names are provided.

    Dictionary of cultivated plants and their regions of diversity : excluding most ornamentals, forest trees and lower plants
    Zeven, A.C. ; Wet, J.M.J. de - \ 1982
    Wageningen : Pudoc - ISBN 9789022007853
    oorsprong - distributie - vestiging - genenbanken - genetische bronnen - germplasm - hulpbronnenbehoud - genetische bronnen van plantensoorten - agronomie - bedektzadigen - wilde planten - flora - plantengeografie - wereld - plantkunde - nieuwe cultuurgewassen - economische botanie - origin - distribution - establishment - gene banks - genetic resources - germplasm - resource conservation - plant genetic resources - agronomy - angiosperms - wild plants - flora - phytogeography - world - botany - new crops - economic botany
    Vleesetende en insectenetende planten
    Anonymous, - \ 1979
    Wageningen : Pudoc (Literatuurlijst / Centrum voor Landbouwpublikaties en Landbouwdocumentatie no. 4317)
    bedektzadigen - bibliografieën - vleesetende planten - insectivore planten - angiosperms - bibliographies - carnivorous plants - insectivorous plants
    Vitality and metabolic properties of binucleate and trinucleate pollen species upon dehiscence
    Hoekstra, F.A. - \ 1979
    Landbouwhogeschool Wageningen. Promotor(en): J. Bruinsma. - Wageningen : Hoekstra - 87
    bedektzadigen - plantenfysiologie - stuifmeel - stuifmeelkieming - openspringen - angiosperms - plant physiology - pollen - pollen germination - dehiscence - cum laude

    Chapter 1

    Effects of various components upon germination in vitro were studied in order to develop an optimal germination medium for Compositae pollen. Equilibration of pollen in humid air, preceding germination, improved the reliability of results considerably.

    Irregular germination ability of pollen samples, originating from different collections, was studied by exposing flowering plants to different climatic conditions. High relative humidity and temperature at dehiscence cause a rapid decrease in pollen vitality. Data for an optimal germination medium and for acquisition of good pollen quality are presented.

    Chapter 2

    The respiration and vitality of ungerminated bi- and trinucleate pollen were studied in order to determine the influence of relative humidity and temperature on metabolic activity. The gas exchange, gerniination capacity and staining with tetrazolium bromide were followed under standardized conditions.

    A constant respiration rate occurred under conditions of high relative humidity (97 %). Per mg pollen, the trinucleate grains of Compositae and Gramineae respired 2 to 3 times as intense as 6 species of binucleate grains. Per unit of pollen protein the differences were even larger. In contrast to binucleate pollen, the longevity of trinucleate pollen was very short and the ability to germinate was lost twice as fast as the respiration capacity. This limits the use of tetrazolium bromide as an indicator of viability.

    At reduced relative humidities respiration was strongly restricted, but the longevity of bi- and trinucleate pollen considerably increased.

    Pollen of Gramineae, however, was very sensitive to changes in relative humidity; short exposure to low relative humidity decreased both the vitality and the capacity to respire.

    Chapter 3

    Bi- and trinucleate pollen generally differ in the extent of their mitochondrial development at anther dehiscence and in the rate of their attainment of maximum-phosphorylative capacity during germination in vitro, as judged from experiments with representatives of both groups.

    The typically trinucleate pollen of Aster tripolium L. immediately respired at a high rate, maintaining a high energy charge. Mitochondria attained maximum electron-transducing capacity within 2 min of incubation, while tube growth started within 3 min. In contrast, the binucleate pollen of Typha latifolia L. only gradually reached a relatively low rate of respiration, concomitant with a temporary decrease in energy charge, upon immersion in the germination medium. Development of the mitochondrial, electron-transducing system occurred in about 75 min, after which the first pollen tubes emerged. Starting from a poor differentiation, mitochondria became increasingly normal in appearance as germination proceeded.

    The binucleate pollen of Nicotiana alata Link et Otto and Tradescantia paludosa Anders. et Woods. showed intermediate characteristics: Nicotiana resembled Typha but mitochondria developed at a higher rate; Tradescantia germinated more rapidly and resembled the trinucleate pollen of Aster.

    Inhibitors of mitochondrial or cytoplasmic protein synthesis failed to affect the development of the mitochondrial, respiratory capacities during pollen germination. It is concluded that the duration of the lag period is determined by the level and rate of mitochondrial development and not by the division of the generative cell.

    Chapter 4

    The equal rates of water vapour absorption by both bi- and trinucleate pollen indicate that their widely-differing rates of respiration have an intrinsic, biochemical basis. This was investigated with various metabolic inhibitors that were previously introduced into dry pollen via anhydrous acetone

    The uncoupler, CCCP, inhibited the O 2 uptake of rapidly respiring pollen and stimulated that of slowly respiring types to similar absolute values, that probably reflect the rates of substrate transport across the mitochondrial membranes.

    The extent of inhibition of the O 2 uptake by oligomycin, DCCD, antimycin A, and SHAM, alone and in combinations, indicates that hardly any oxidative phosphorylation and anabolic activities occur in slowly respiring, binucleate pollen species, having low-developed mitochondria and high EC values. The presence of the alternative pathway was insignificant.

    In other binucleate pollen species, characterized by recognizable mitochondria and low EC values, a limited ATP synthesis was established. The low EC values point to imbalance between phosphorylative and anabolic activities.

    In rapidly respiring, trinucleate pollen, containing well- developed mitochondria, a significant activity of the alternative oxidase was found. The EC values were high notwithstanding the large demand for ATP, mounting to 1.7 μmol h -1mg pollen -1.

    In some pollen species, oligomycin highly stimulated the flow of electrons through the cytochrome pathway, which made an estimation of the ATP synthesis impossible.

    Chapter 5

    Under humid conditions both bi- and trinucleate pollen species incorporate very low amounts of leucine, 0.4 pmol min -1mg pollen -1on an average. During germination in vitro , however, the two types of pollen greatly differ in their capacity for protein synthesis.

    Binucleate pollen species such as Typha , which are characterized by slow respiration in humid air and prolonged lag periods during germination in vitro , contain large amounts of monoribosomes at dehiscence. Polyribosomes are formed soon after the pollen is wetted in the germination medium and a considerable incorporation of leucine is initiated after 10-15 min.

    More rapidly respiring, binucleate pollen, such as Tradescantia , showing a short lag period, may contain many polysomes at dehiscence already and incorporates leucine within 2 min of incubation.

    On the contrary, rapidly respiring, trinucleate Compositae pollen contains very limited amounts of ribosomal material and never attains any substantial level of incorporation.

    Cycloheximide completely inhibited both protein synthesis and tube emergence and growth in the slowly respiring binucleate pollen species. The more rapidly respiring types are less dependent on protein synthesis, while germination of the phylogenetically advanced, trinucleate Compositae pollen proceeds completely independently.

    It is concluded that the level of phylogenetic advancement of the male gametophyte is characterized by its overall state of metabolic development at dehiscence rather than by the number of its generative cells.

    Contribution a l'etude ethnobotanique des Wagenia de Kisangani, Zaire
    Bokdam, J. ; Droogers, A.F. - \ 1975
    Wageningen : Veenman (Mededelingen Landbouwhogeschool Wageningen 75-19) - 74
    bedektzadigen - oorsprong - distributie - vestiging - etnografie - antropologie - wilde planten - plantkunde - volkscultuur - democratische republiek kongo - nieuwe cultuurgewassen - gebruiken - volkenkunde - economische botanie - angiosperms - origin - distribution - establishment - ethnography - anthropology - wild plants - botany - folk culture - congo democratic republic - new crops - customs - ethnology - economic botany
    Dictionary of cultivated plants and their centres of diversity : excluding ornamentals, forest trees and lower plants
    Zeven, A.C. ; Zhukovsky, P.M. - \ 1975
    Wageningen : Pudoc - ISBN 9789022005491
    oorsprong - distributie - vestiging - agronomie - bedektzadigen - wereld - plantkunde - wilde planten - flora - plantengeografie - nieuwe cultuurgewassen - economische botanie - origin - distribution - establishment - agronomy - angiosperms - world - botany - wild plants - flora - phytogeography - new crops - economic botany
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