E PLANTAS: Fundamentos E Importância

Total Page:16

File Type:pdf, Size:1020Kb

E PLANTAS: Fundamentos E Importância NEMATOLOGIA DE PLANTAS: fundamentos e importância ii NEMATOLOGIA DE PLANTAS: fundamentos e importância Organizado por Luiz Carlos C. Barbosa Ferraz Docente aposentado da Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, Brasil Derek John F inlay Brown Pesquisador aposentado do Scottish Crop Research Institute (SCRI), atual James Hutton Institute, Dundee, Escócia uma publicação da iii Sociedade Brasileira de Nematologia / SBN Sede atual: Universidade Estadual do Norte Fluminense Darcy Ribeiro / CCTA. Av. Alberto Lamego, 2000 – Parque California 28013-602 – Campos dos Goytacazes (RJ) – Brasil E-mail: [email protected] Telefone: (22) 3012-4821 Site: http://nematologia.com.br © Sociedade Brasileira de Nematologia 2016. Todos os direitos reservados. É vedada a reprodução desta publicação, ou de suas partes, na forma impressa ou por outros meios, sem prévia autorização do representante legal da SBN. A sua utilização poderá vir a ocorrer estritamente para fins didáticos, em caráter eventual e com a citação da fonte. Ficha catalográfica elaborada por Marilene de Sena e Silva - CRB/AM Nº 561 F368 n FERRAZ, L.C.C.B.; BROWN, D.J.F. Nematologia de plantas: fundamentos e importância. L.C.C.B. Ferraz e D.J.F. Brown (Orgs.). Manaus: NORMA EDITORA, 2016. 251 p. Il. ISBN: 978-85-99031-26-1 2. Nematologia. 2. Doenças de plantas. 3. Vermes. I. Ferraz & Brown. II. Título. CDD: 632 iv Para Maria Teresa, Alex e Thais, que souberam entender a minha irresistível atração pela Nematologia e aceitar as muitas horas de plena dedicação a ela. In memoriam Alexandre M. Cintra Goulart, Anário Jaehn, Dimitry Tihohod, José Julio da Ponte, Luiz G. E. Lordello, Martin Homechin, Shiou Pin Huang e Wilson R. T. Novaretti. Educadores fitonematológicos. Pessoas inesquecíveis. v Conteúdo Sobre os autores ................................................................................................ ................... xi Prefácio ............................................................................................. ................... ............... xii 1 Os nematoides no contexto da Agricultura atual ............... ................ .......................... 1 1.1 Introdução .................................................................................................................. 1 1.2 Conhecendo os nematoides ........................................................................................ 4 1.3 Nematoides: os inimigos invisíveis das plantas ......................................................... 8 1.4 Um pouco da história da Nematologia de Plantas ..................................................... 9 1.5 Identificando os principais grupos e espécies de fitonematoides .............................13 Literatura consultada e/ou sugerida para leitura ...................................................... 15 2 Morfologia, estrutura e sistemas funcionais ....................... ........................................ 17 2.1 Tamanho e forma .................................................................................................... 17 2.2 A parede do corpo .................................................................. ................................. 19 2.3 O pseudoceloma .......................................................................................................24 2.4 Sistema digestório ....................................................................... ............................ 25 2.5 Sistema excretor-secretor ........................................................................................ 30 2.6 Sistema nervoso ...................................................................................................... 31 Literatura consultada e/ou sugerida para leitura ..................................................... 31 3 Reprodução e eventos relacionados ....... ...................................................................... 33 3.1 Introdução .............................................................................................................. 33 3.2 Sistema reprodutor feminino .................... .............................................................. 33 3.3 Sistema reprodutor masculino ................................................................................ 37 3.4 Modos de reprodução ................................................. ............................................ 39 vi 3.5 Determinação do sexo ............................................................................................ 41 3.6 O ovo ...................................................................................................................... 42 3.7 Eclosão ................................................................................................................... 44 Literatura consultada e/ou sugerida para consulta ................................................... 45 4 Principais aspectos bioecológicos ................................................................................ 46 4.1 Introdução .............................................................................................................. 46 4.2 Características biológicas gerais ............................................................................ 47 4.2.1 O ciclo de vida e aspectos correlatos ............................................................. 47 4.2.2 Estratégias de sobrevivência .......................................................................... 50 4.3 Fatores que afetam as populações de fitonematoides ............................................ 54 4.4 Aspectos epidemiológicos das fitonematoses ....................................................... 58 4.4.1 Distribuição no solo ....................................................................................... 58 4.4.2 Dispersão ....................................................................................................... 60 Literatura consultada e/ou sugerida para consulta .................................................. 65 5 Interação planta-nematoide: estratégias de alimentação ......................................... 66 5.1 Considerações iniciais ........................................................................................... 66 5.2 Ectoparasitas ......................................................................................................... 67 5.2.1 Classe Enoplea .............................................................................................. 67 5.2.1.1 Família Longidoridae ............................................................................. 68 5.2.1.2 Família Trichodoridae ............................................................................ 71 5.2.2 Classe Chromadorea ..................................................................................... 74 5.3 Endoparasitas e semiendoparasitas ....................................................................... 80 5.3.1 Endoparasitas migradores ............................................................................. 80 5.3.2 Endoparasitas sedentários ............................................................................. 82 5.3.2.1 Meloidogyne .......................................................................................... 82 5.3.2.2 Globodera e Heterodera ......................................................................... 85 5.3.3 Semiendoparasitas sedentários ...................................................................... 87 vii 5.3.3.1 Rotylenchulus ........................................................................................ 87 5.3.3.2 Tylenchulus ........................................................................................... 88 5.4 Considerações finais ............................................................................................. 89 Literatura consultada e/ou sugerida para consulta .................................................. 90 6 Principais nematoides ectoparasitas e semiendoparasitas ....................................... 92 6.1 Introdução: os modos de parasitismo ................................................................... 92 6.2 Secernentia / principais casos de ectoparasitismo ................................................ 94 6.2.1 Criconematoidea ............................................................................................ 94 6.2.1.1 Criconemoides xenoplax ........................................................................ 94 6.2.1.2 Hemicycliophora arenaria ...................................................................... 96 6.2.2 Tylenchoidea ................................................................................................. 97 6.2.2.1 (Belonolaimidae) Belonolaimus longicaudatus ..................................... 97 6.2.2.2 (Belonolaimidae) Tylenchorhynchus annulatus / T.claytoni ….…........ 99 6.2.2.3 (Hoplolaimidae) Helicotylenchus multicinctus ……….…………...... 100 6.2.2.4 (Hoplolaimidae) Scutellonema bradys …………………………….... 102 6.2.2.5 (Hoplolaimidae) Hoplolaimus columbus ………………………..........103 6.3 Dorylaimia e Enoplia / principais casos de ectoparasitismo ............................. 105 6.3.1 (Longidoridae) Longidorus, Paralongidorus e Xiphinema ......................... 105 6.3.2 (Trichodoridae) Paratrichodorus e Trichodorus ......................................... 108 6.4 Secernentia / principais casos de semiendoparasitismo .................................... 112 6.4.1 O gênero Rotylenchulus: nematoides
Recommended publications
  • Gastrointestinal Helminthic Parasites of Habituated Wild Chimpanzees
    Aus dem Institut für Parasitologie und Tropenveterinärmedizin des Fachbereichs Veterinärmedizin der Freien Universität Berlin Gastrointestinal helminthic parasites of habituated wild chimpanzees (Pan troglodytes verus) in the Taï NP, Côte d’Ivoire − including characterization of cultured helminth developmental stages using genetic markers Inaugural-Dissertation zur Erlangung des Grades eines Doktors der Veterinärmedizin an der Freien Universität Berlin vorgelegt von Sonja Metzger Tierärztin aus München Berlin 2014 Journal-Nr.: 3727 Gedruckt mit Genehmigung des Fachbereichs Veterinärmedizin der Freien Universität Berlin Dekan: Univ.-Prof. Dr. Jürgen Zentek Erster Gutachter: Univ.-Prof. Dr. Georg von Samson-Himmelstjerna Zweiter Gutachter: Univ.-Prof. Dr. Heribert Hofer Dritter Gutachter: Univ.-Prof. Dr. Achim Gruber Deskriptoren (nach CAB-Thesaurus): chimpanzees, helminths, host parasite relationships, fecal examination, characterization, developmental stages, ribosomal RNA, mitochondrial DNA Tag der Promotion: 10.06.2015 Contents I INTRODUCTION ---------------------------------------------------- 1- 4 I.1 Background 1- 3 I.2 Study objectives 4 II LITERATURE OVERVIEW --------------------------------------- 5- 37 II.1 Taï National Park 5- 7 II.1.1 Location and climate 5- 6 II.1.2 Vegetation and fauna 6 II.1.3 Human pressure and impact on the park 7 II.2 Chimpanzees 7- 12 II.2.1 Status 7 II.2.2 Group sizes and composition 7- 9 II.2.3 Territories and ranging behavior 9 II.2.4 Diet and hunting behavior 9- 10 II.2.5 Contact with humans 10 II.2.6
    [Show full text]
  • Morphological and Molecular Characterisation of Scutellonema Species from Yam (Dioscorea Spp.) and a Key to the Species of the Genus ∗ Yao A
    Nematology 00 (2017) 1-37 brill.com/nemy Morphological and molecular characterisation of Scutellonema species from yam (Dioscorea spp.) and a key to the species of the genus ∗ Yao A. K OLOMBIA 1,2, , Gerrit KARSSEN 1,3,NicoleVIAENE 1,4,P.LavaKUMAR 2,LisaJOOS 1, ∗ Danny L. COYNE 5 and Wim BERT 1, 1 Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium 2 International Institute of Tropical Agriculture (IITA), PMB 5320, Oyo Road, Ibadan, Nigeria 3 National Plant Protection Organization, 6706 EA Wageningen, The Netherlands 4 Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), B-9820 Merelbeke, Belgium 5 IITA, Kasarani, P.O. Box 30772-00100, Nairobi, Kenya Received: 22 February 2017; revised: 30 May 2017 Accepted for publication: 1 June 2017; available online: ??? Summary – The yam nematode, Scutellonema bradys, is a major threat to yam (Dioscorea spp.) production across yam-growing regions. In West Africa, this species cohabits with many morphologically similar congeners and, consequently, its accurate diagnosis is essential for control and for monitoring its movement. In the present study, 46 Scutellonema populations collected from yam rhizosphere and yam tubers in different agro-ecological zones in Ghana and Nigeria were characterised by their morphological features and by sequencing of the D2-D3 region of the 28S rDNA gene and the mitochondrial COI genes. Molecular phylogeny, molecular species delimitation and morphology revealed S. bradys, S. cavenessi, S. clathricaudatum and three undescribed species from yam rhizosphere. Only S. bradys was identified from yam tuber tissue, however. For barcoding and identifying Scutellonema spp., the most suitable marker used was the COI gene.
    [Show full text]
  • Morphological and Molecular Characterization of Longidorus Americanum N
    Journal of Nematology 37(1):94–104. 2005. ©The Society of Nematologists 2005. Morphological and Molecular Characterization of Longidorus americanum n. sp. (Nematoda: Longidoridae), aNeedle Nematode Parasitizing Pine in Georgia Z. A. H andoo, 1 L. K. C arta, 1 A. M. S kantar, 1 W. Y e , 2 R. T. R obbins, 2 S. A. S ubbotin, 3 S. W. F raedrich, 4 and M. M. C ram4 Abstract: We describe and illustrate anew needle nematode, Longidorus americanum n. sp., associated with patches of severely stunted and chlorotic loblolly pine, ( Pinus taeda L.) seedlings in seedbeds at the Flint River Nursery (Byromville, GA). It is characterized by having females with abody length of 5.4–9.0 mm; lip region slightly swollen, anteriorly flattened, giving the anterior end atruncate appearance; long odontostyle (124–165 µm); vulva at 44%–52% of body length; and tail conoid, bluntly rounded to almost hemispherical. Males are rare but present, and in general shorter than females. The new species is morphologically similar to L. biformis, L. paravineacola, L. saginus, and L. tarjani but differs from these species either by the body, odontostyle and total stylet length, or by head and tail shape. Sequence data from the D2–D3 region of the 28S rDNA distinguishes this new species from other Longidorus species. Phylogenetic relationships of Longidorus americanum n. sp. with other longidorids based on analysis of this DNA fragment are presented. Additional information regarding the distribution of this species within the region is required. Key words: DNA sequencing, Georgia, loblolly pine, Longidorus americanum n. sp., molecular data, morphology, new species, needle nematode, phylogenetics, SEM, taxonomy.
    [Show full text]
  • Summary Paratrichodorus Minor Is a Highly Polyphagous Plant Pest, Generally Found in Tropical Or Subtropical Soils
    CSL Pest Risk Analysis for Paratrichodorus minor copyright CSL, 2008 CSL PEST RISK ANALYSIS FOR Paratrichodorus minor Abstract/ Summary Paratrichodorus minor is a highly polyphagous plant pest, generally found in tropical or subtropical soils. It has entered the UK in growing media associated with palm trees and is most likely to establish on ornamental plants grown under protection. There is a moderate likelihood of the pest establishing outdoors in the UK through the planting of imported plants in gardens or amenity areas. However there is a low likelihood of the nematode spreading from such areas to commercial food crops, to which it presents a small risk of economic impact. P. minor is known to vector the Tobacco rattle virus (TRV), which affects potatoes, possibly strains that are not already present in the UK, but the risk of the nematode entering in association with seed potatoes is low. Overall the risk of P. minor to the UK is rated as low. STAGE 1: PRA INITIATION 1. What is the name of the pest? Paratrichodorus minor (Colbran, 1956) Siddiqi, 1974 Nematode: Trichodoridae Synonyms: Paratrichodorus christiei (Allen, 1957) Siddiqi, 1974 Paratrichodorus (Nanidorus) christiei (Allen, 1957) Siddiqi, 1974 Paratrichodorus (Nanidorus) minor (Colbran, 1956) Siddiqi, 1974 Trichodorus minor Colbran, 1956 Trichodorus christiei Allen, 1957 Nanidorus minor (Colbran, 1956) Siddiqi, 1974 Nanidorus christiei (Allen, 1957) Siddiqi, 1974 Trichodorus obesus Razjivin & Penton, 1975 Paratrichodorus obesus (Razjivin & Penton, 1975) Rodriguez-M. & Bell, 1978. Paratrichodorus (Nanidorus) obesus (Razjivin & Penton, 1975) Rodriguez-M. & Bell, 1978. Common names: English: a stubby-root nematode. References: Decraemer, 1995 In Europe there has been some confusion between P.
    [Show full text]
  • First Report of Stubby Root Nematode, Paratrichodorus Teres (Nematoda: Trichodoridae) from Iran
    Australasian Plant Dis. Notes (2014) 9:131 DOI 10.1007/s13314-014-0131-4 First report of stubby root nematode, Paratrichodorus teres (Nematoda: Trichodoridae) from Iran R. Heydari & Z. Tanha Maafi & F. Omati & W. Decraemer Received: 8 October 2013 /Accepted: 20 March 2014 /Published online: 4 April 2014 # Australasian Plant Pathology Society Inc. 2014 Abstract During a survey of plant-parasitic nematodes in fruit Trichodorus, Nanidorus and Paratrichodorus are natural tree nurseries in Iran, a species of the genus Paratrichodorus vectors of the plant Tobraviruses occurring worldwide from the family Trichodoridae was found in the rhizosphere of (Taylor and Brown 1997; Decraemer and Geraert 2006). apricot seedlings in Shahrood, central Iran, then subsequently in Eight species of the Trichodoridae family have so far been Karaj orchards. Morphological and morphometric characters of reported from Iran: Trichodorus orientalis (De Waele and the specimens were in agreement with P. teres.TheD2/D3 Hashim 1983), T. persicus (De Waele and Sturhan 1987), expansion fragment of the large subunit (LSU) of rRNA gene T. gilanensis, T. primitivus, Paratrichodorus porosus, P. of the nematode was also sequenced. P. teres is considered an tunisiensis (Maafi and Decraemer 2002), T. arasbaranensis economically important species in agricultural crop, worldwide. (Zahedi et al. 2009)andP. mi no r (now Nanidorus minor) This is the first report of the occurrence of P. teres in Iran. (Pourjam et al. 2011). Several species were detected in a survey conducted on Keywords Apricot . Fruit tree nursery . Iran . plant-parasitic nematodes in fruit tree nurseries. Among Paratrichodorus teres them, a nematode population belonging to Trichodoridae was observed in the rhizosphere of apricot seedlings in Shahroood, Semnan province, central Iran, that was sub- Trichodorid nematodes are root ectoparasites, usually sequently identified as P.
    [Show full text]
  • Description and Molecular Characterisation of Paralongidorus Litoralis Sp.N.Andp
    Nematology, 2008, Vol. 10(1), 87-101 Description and molecular characterisation of Paralongidorus litoralis sp.n.andP. paramaximus Heyns, 1965 (Nematoda: Longidoridae) from Spain Juan E. PALOMARES-RIUS 1,SergeiA.SUBBOTIN 2,3,BlancaB.LANDA 1, ∗ Nicola VOVLAS 4 and Pablo CASTILLO 1, 1 Institute of Sustainable Agriculture, Spanish National Research Council (CSIC), Alameda del Obispo s/n, Apdo. 4084, 14080 Córdoba, Spain 2 Plant Pest Diagnostics Center, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832-1448, USA 3 Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, Moscow, 117071, Russia 4 Istituto per la Protezione delle Piante, Sezione di Bari, Consiglio Nazionale delle Ricerche, (CNR), Via G. Amendola 165/A, 70126 Bari, Italy Received: 17 July 2007; revised: 23 August 2007 Accepted for publication: 23 August 2007 Summary – Paralongidorus litoralis sp. n., a new bisexual species of the genus, is described and illustrated by light microscopy, scanning electron microscopy and molecular studies from specimens collected in a coastal sand dune soil around roots of lentisc (Pistacia lentiscus L.) from Zahara de los Atunes (Cadiz), southern Spain. Paralongidorus litoralis sp. n. is characterised by the large body size (7.5-10.0 mm), a rounded lip region, clearly offset from the body by a collar-like constriction, and bearing a very large stirrup-shaped, amphidial fovea, with conspicuous slit-like aperture, a very long and flexible odontostyle ca 190 µm long, guiding ring located at 35 µm from anterior end, and males with spicules ca 70 µm long.
    [Show full text]
  • The Types of Supplements in the Family Tobrilidae (Nematoda, Enoplia) Alexander V
    Russian Journal of Nematology, 2015, 23 (2), 81 – 90 The types of supplements in the family Tobrilidae (Nematoda, Enoplia) Alexander V. Shoshin1, Ekaterina A. Shoshina1 and Julia K. Zograf2, 3 1Zoological Institute, Russian Academy of Sciences, Universitetskaya Naberezhnaya 1, 199034, Saint Petersburg, Russia 2A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of the Russian Academy of Sciences, Paltchevsky Street 17, 690041, Vladivostok, Russia 3Far Eastern Federal University, Sukhanova Street 8, 690090, Vladivostok, Russia e-mail: [email protected] Accepted for publication 11 October 2015 Summary. The structure of supplementary organs and buccal cavity are the main diagnostic features for identification of Tobrilidae species. Four main supplement types can be distinguished among representatives of this family. Type I supplements are typical for Tobrilus, Lamuania and Semitobrilus and are characterised by their small size and slightly protruding external part. There are two variations of the type I supplement structure: amabilis and gracilis. Type II is typical for several Eutobrilus species (E. peregrinator, E. prodigiosus, E. strenuus, E. nothus). These supplements are very similar to the type I supplements but are characterised in having a highly protruding torus with numerous microthorns and a bulbulus situated at the base of the ampoule. Type III is typical for Eutobrilus species from the Tobrilini tribe, i.e., E. graciliformes, E. papilicaudatus and E. differtus, and Mesotobrilus spp. from the Paratrilobini tribe and is characterised by a well-defined cap and a bulbulus situated at the base of the ampoule. Type IV is observed in the majority of Eutobrilus, Paratrilobus, Brevitobrilus and Neotobrilus and is the most complex supplement type with a mobile cap and an apical bulbulus.
    [Show full text]
  • PCR-RFLP and Sequencing Analysis of Ribosomal DNA of Bursaphelenchus Nematodes Related to Pine Wilt Disease(L)
    Fundam. appl. Nemalol., 1998,21 (6), 655-666 PCR-RFLP and sequencing analysis of ribosomal DNA of Bursaphelenchus nematodes related to pine wilt disease(l) Hideaki IvVAHORI, Kaku TSUDA, Natsumi KANZAKl, Katsura IZUI and Kazuyoshi FUTAI Cmduate School ofAgriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. Accepted for publication 23 December 1997. Summary -A polymerase chain reaction - restriction fragment polymorphism (PCR-RFLP) analysis was used for the discri­ mination of isolates of Bursaphelenchus nematode. The isolares of B. xylophilus examined originared from Japan, the United Stares, China, and Canada and the B. mucronatus isolates from Japan, China, and France. Ribosomal DNA containing the 5.8S gene, the internai transcribed spacer region 1 and 2, and partial regions of 18S and 28S gene were amplified by PCR. Digestion of the amplified products of each nematode isolate with twelve restriction endonucleases and examination of resulting RFLP data by cluster analysis revealed a significant gap between B. xylophllus and B. mucronatus. Among the B. xylophilus isolares examined, Japanese pathogenic, Chinese and US isolates were ail identical, whereas Japanese non-pathogenic isolares were slightly distinct and Canadian isolates formed a separate cluster. Among the B. mucronalUS isolates, two Japanese isolares were very similar to each other and another Japanèse and one Chinese isolare were identical to each other. The DNA sequence data revealed 98 differences (nucleotide substitutions or gaps) in 884 bp investigated between B. xylophilus isolare and B. mucronmus isolate; DNA sequence data of Aphelenchus avenae and Aphelenchoides fragariae differed not only from those of Bursaphelenchus nematodes, but also from each other.
    [Show full text]
  • 2020.01.27.921304.Full.Pdf
    bioRxiv preprint doi: https://doi.org/10.1101/2020.01.27.921304; this version posted January 28, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 A novel metabarcoding strategy for studying nematode 2 communities 3 4 Md. Maniruzzaman Sikder1, 2, Mette Vestergård1, Rumakanta Sapkota3, Tina Kyndt4, 5 Mogens Nicolaisen1* 6 7 1Department of Agroecology, Aarhus University, Slagelse, Denmark 8 2Department of Botany, Jahangirnagar University, Savar, Dhaka, Bangladesh 9 3Department of Environmental Science, Aarhus University, Roskilde, Denmark 10 4Department of Biotechnology, Ghent University, Ghent, Belgium 11 12 13 *Corresponding author 14 Email: [email protected] 15 16 Abstract 17 Nematodes are widely abundant soil metazoa and often referred to as indicators of soil health. 18 While recent advances in next-generation sequencing technologies have accelerated 19 research in microbial ecology, the ecology of nematodes remains poorly elucidated, partly due 20 to the lack of reliable and validated sequencing strategies. Objectives of the present study 21 were (i) to compare commonly used primer sets and to identify the most suitable primer set 22 for metabarcoding of nematodes; (ii) to establish and validate a high-throughput sequencing 23 strategy for nematodes using Illumina paired-end sequencing. In this study, we tested four 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.01.27.921304; this version posted January 28, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • A Phylogenetic Tree of Nematodes Based on About 1200 Full-Length
    Nematology, 2009, Vol. 11(6), 927-950 A phylogenetic tree of nematodes based on about 1200 full-length small subunit ribosomal DNA sequences ∗ Hanny VA N MEGEN 1,SvenVA N D E N ELSEN 1, Martijn HOLTERMAN 1, , Gerrit KARSSEN 2, Paul MOOYMAN 1,TomBONGERS 1, Oleksandr HOLOVACHOV 3, ∗∗ Jaap BAKKER 1 and Johannes HELDER 1, 1 Laboratory of Nematology, Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands 2 Plant Protection Service, Nematology Section, Geertjesweg 15, 6706 EA Wageningen, The Netherlands 3 Department of Nematology, University of California at Riverside, Riverside, CA 92521, USA Received: 8 December 2008; revised: 30 April 2009 Accepted for publication: 1 May 2009 Summary – As a result of the scarcity of informative morphological and anatomical characters, nematode systematics have always been volatile. Differences in the appreciation of these characters have resulted in numerous classifications and this greatly confuses scientific communication. An advantage of the use of molecular data is that it allows for an enormous expansion of the number of characters. Here we present a phylogenetic tree based on 1215 small subunit ribosomal DNA sequences (ca 1700 bp each) covering a wide range of nematode taxa. Of the 19 nematode orders mentioned by De Ley et al. (2006) 15 are represented here. Compared with Holterman et al. (2006) the number of taxa analysed has been tripled. This did not result in major changes in the clade subdivision of the phylum, although a decrease in the number of well supported nodes was observed. Especially at the family level and below we observed a considerable congruence between morphology and ribosomal DNA-based nematode systematics and, in case of discrepancies, morphological or anatomical support could be found for the alternative grouping in most instances.
    [Show full text]
  • Phylogenetic and Population Genetic Studies on Some Insect and Plant Associated Nematodes
    PHYLOGENETIC AND POPULATION GENETIC STUDIES ON SOME INSECT AND PLANT ASSOCIATED NEMATODES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Amr T. M. Saeb, M.S. * * * * * The Ohio State University 2006 Dissertation Committee: Professor Parwinder S. Grewal, Adviser Professor Sally A. Miller Professor Sophien Kamoun Professor Michael A. Ellis Approved by Adviser Plant Pathology Graduate Program Abstract: Throughout the evolutionary time, nine families of nematodes have been found to have close associations with insects. These nematodes either have a passive relationship with their insect hosts and use it as a vector to reach their primary hosts or they attack and invade their insect partners then kill, sterilize or alter their development. In this work I used the internal transcribed spacer 1 of ribosomal DNA (ITS1-rDNA) and the mitochondrial genes cytochrome oxidase subunit I (cox1) and NADH dehydrogenase subunit 4 (nd4) genes to investigate genetic diversity and phylogeny of six species of the entomopathogenic nematode Heterorhabditis. Generally, cox1 sequences showed higher levels of genetic variation, larger number of phylogenetically informative characters, more variable sites and more reliable parsimony trees compared to ITS1-rDNA and nd4. The ITS1-rDNA phylogenetic trees suggested the division of the unknown isolates into two major phylogenetic groups: the HP88 group and the Oswego group. All cox1 based phylogenetic trees agreed for the division of unknown isolates into three phylogenetic groups: KMD10 and GPS5 and the HP88 group containing the remaining 11 isolates. KMD10, GPS5 represent potentially new taxa. The cox1 analysis also suggested that HP88 is divided into two subgroups: the GPS11 group and the Oswego subgroup.
    [Show full text]
  • Nematodes in Aquatic Environments Adaptations and Survival Strategies
    Biodiversity Journal , 2012, 3 (1): 13-40 Nematodes in aquatic environments: adaptations and survival strategies Qudsia Tahseen Nematode Research Laboratory, Department of Zoology, Aligarh Muslim University, Aligarh-202002, India; e-mail: [email protected]. ABSTRACT Nematodes are found in all substrata and sediment types with fairly large number of species that are of considerable ecological importance. Despite their simple body organization, they are the most complex forms with many metabolic and developmental processes comparable to higher taxa. Phylum Nematoda represents a diverse array of taxa present in subterranean environment. It is due to the formative constraints to which these individuals are exposed in the interstitial system of medium and coarse sediments that they show pertinent characteristic features to survive successfully in aquatic environments. They represent great degree of mor - phological adaptations including those associated with cuticle, sensilla, pseudocoelomic in - clusions, stoma, pharynx and tail. Their life cycles as well as development seem to be entrained to the environment type. Besides exhibiting feeding adaptations according to the substrata and sediment type and the kind of food available, the aquatic nematodes tend to wi - thstand various stresses by undergoing cryobiosis, osmobiosis, anoxybiosis as well as thio - biosis involving sulphide detoxification mechanism. KEY WORDS Adaptations; fresh water nematodes; marine nematodes; morphology; ecology; development. Received 24.01.2012; accepted 23.02.2012;
    [Show full text]