NEMATODE TAXONOMY and SYSTEMATICS NEM 6102 Course

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NEMATODE TAXONOMY and SYSTEMATICS NEM 6102 Course NEMATODE TAXONOMY AND SYSTEMATICS NEM 6102 Course Format: 1 hour lecture, 2 hour lab Credit Hours: 2 credits Prerequisites: None Instructor: Tesfamariam Mengistu (Tesfa), email: [email protected] Course Description: NEM 6102 will provide an introduction to history of nematode taxonomy, recent nematode taxonomy and systematics methods Learn classical and modern identification techniques Expected Learning Outcomes Upon completion of this course, student will be able to: Possess theoretical and practical background in nematode taxonomy and systematics Acquainted with classical and modern methods in nematode taxonomy Appreciate the importance of nematode systematics Recognize the value of nematode systematics Comprehends the role of classical and modern methods in nematode systematics Reference Books (available to borrow from my lab): The Biology of Nematodes, Donald Lee, 2002 Dorylaimida: free-living, predaceous and plant-parasitic nematodes. Jairajpuri and Ahmad, 1992 A taxonomic review of the suborder Rhabditida. Andrassy, 1983 Peer reviewed taxonomy articles (provided by the instructor) Evaluation Non-period evaluation (10%): Evaluation of the guided lab sessions and independent practical task Period evaluation (90%): on all elements of the theoretical part of the course by a written (80%) Grading scale A 90 - 100 points B+ 88 - 89 points B 80 - 87 points C+ 78 - 79 points C 70 - 77 points D 60 - 69 points E <60 Exams (Mid and final): All exams will be comprehensive but will emphasize material covered during lectures. All exams will be written and will include short answer and essay questions. Laboratory Exercises: Lab reports and permanent slides of at least 10 different genera of nematodes Project: New species description (using morphology and molecular methods); taxonomic paper review and critic. Lecture schedule Class 1 General taxonomy and systematics Class 2 Higher nematode taxonomy and systematics ( nomenclature) Class 3 How to write a taxonomy paper Class 4 Order Rhabditida Class 5 Order Triplonchida Class 6 Order Dorylaimida Class 7 Order Mononchida Class 8 Midterm exam Class 9 Identification guides for the most common genera of plant parasitic nematodes Class 10 Identification guides for the most common species of plant parasitic nematodes Class 11 Insect parasitic nematodes: Order Mermithida, Oxyurida Class 12 Molecular phylogeny and systematics I Class 13 Molecular phylogeny and systematics II Class 14 Final exam Lab Schedule Lab 1 Introduction Lab 2 Identification exercise: higher level classifications Lab 3 Data mining in taxonomic paper writing Lab 4 Sample processing: fixation, mounting, permanent slides Lab 5 Order Rhabditida lab exercise I Lab 6 Order Rhabditida lab exercise II Lab 7 Order Triplonchida lab exercise Lab 8 Mid-term exam Lab 9 Order Dorylaimida lab exercise Lab 10 Order Mononchida lab exercise Lab 11 Identification of entomopathogenic nematodes Lab 12 Molecular methods (DNA extraction, PCR, cloning) Lab 13 Molecular methods (Sequencing, phylogeny and common bioinformatics methods) Lab 14 Final exam .
Recommended publications
  • 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.
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  • Characterisation of Populations of Longidorus Orientalis Loof, 1982
    Nematology 17 (2015) 459-477 brill.com/nemy Characterisation of populations of Longidorus orientalis Loof, 1982 (Nematoda: Dorylaimida) from date palm (Phoenix dactylifera L.) in the USA and other countries and incongruence of phylogenies inferred from ITS1 rRNA and coxI genes ∗ Sergei A. SUBBOTIN 1,2,3, ,JasonD.STANLEY 4, Antoon T. PLOEG 3,ZahraTANHA MAAFI 5, Emmanuel A. TZORTZAKAKIS 6, John J. CHITAMBAR 1,JuanE.PALOMARES-RIUS 7, Pablo CASTILLO 7 and Renato N. INSERRA 4 1 Plant Pest Diagnostic Center, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832-1448, USA 2 Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, Moscow 117071, Russia 3 Department of Nematology, University of California Riverside, Riverside, CA 92521, USA 4 Florida Department of Agriculture and Consumer Services, DPI, Nematology Section, P.O. Box 147100, Gainesville, FL 32614-7100, USA 5 Iranian Research Institute of Plant Protection, P.O. Box 1454, Tehran 19395, Iran 6 Plant Protection Institute, N.AG.RE.F., Hellenic Agricultural Organization-DEMETER, P.O. Box 2228, 71003 Heraklion, Crete, Greece 7 Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Campus de Excelencia Internacional Agroalimentario, ceiA3, Apdo. 4084, 14080 Córdoba, Spain Received: 16 January 2015; revised: 16 February 2015 Accepted for publication: 16 February 2015; available online: 27 March 2015 Summary – Needle nematode populations of Longidorus orientalis associated with date palm, Phoenix dactylifera, and detected during nematode surveys conducted in Arizona, California and Florida, USA, were characterised morphologically and molecularly. The nematode species most likely arrived in California a century ago with propagative date palms from the Middle East and eventually spread to Florida on ornamental date palms that were shipped from Arizona and California.
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  • Molecular and Morphological Characterisation of Species
    Nematology, 2011, Vol. 13(3), 295-306 Molecular and morphological characterisation of species within the Xiphinema americanum-group (Dorylaimida: Longidoridae) from the central valley of Chile ∗ Pablo MEZA 1,2, ,ErwinABALLAY 1 and Patricio HINRICHSEN 2 1 Faculty of Agronomy, Universidad de Chile, Avenida Santa Rosa 11315, Santiago, Chile 2 Biotechnology Laboratory, INIA La Platina, Avenida Santa Rosa 11610, Santiago, Chile Received: 7 January 2010; revised: 21 June 2010 Accepted for publication: 21 June 2010 Summary – Species of the Xiphinema americanum-group are among the most damaging nematodes for a diverse range of crops. This group includes 51 nominal species throughout the world. They are very difficult to identify by traditional taxonomic methods. Despite its importance in agriculture, the species composition of this group in many countries, including Chile, remains unknown. In order to identify the species in the central valley of Chile, we studied the morphological, morphometric and molecular diversity of 13 populations. Through classical taxonomic methods two species, X. inaequale and X. peruvianum, were identified with clear differences in the shape of the lip region. The DNA sequences of the ITS of ribosomal genes revealed divergences in the nucleotide sequences of the two species from 7.3% in ITS1 to 14.7% in ITS2. These results confirmed the presence of two distinct species, namely X. peruvianum and X. inaequale, in the northern and southern parts of the central valley of Chile, respectively. PCR-RFLP was developed for rapid species identification of these two species. Keywords – molecular, morphology, morphometrics, taxonomy, Xiphinema californicum, Xiphinema inaequale, Xiphinema peruvia- num. The Xiphinema americanum-group comprises 51 nom- nologies has opened a new spectrum of possibilities in ne- inal species found all over the world (Lamberti et al., matode taxonomy.
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  • Transcriptome Profiling of the Root-Knot Nematode Meloidogyne Enterolobii During Parasitism and Identification of Novel Effector Proteins
    Ecole Doctorale de Sciences de la Vie et de la Santé Unité de recherche : UMR ISA INRA 1355-UNS-CNRS 7254 Thèse de doctorat Présentée en vue de l’obtention du grade de docteur en Biologie Moléculaire et Cellulaire de L’UNIVERSITE COTE D’AZUR par NGUYEN Chinh Nghia Etude de la régulation du transcriptome de nématodes parasites de plante, les nématodes à galles du genre Meloidogyne Dirigée par Dr. Bruno FAVERY Soutenance le 8 Décembre, 2016 Devant le jury composé de : Pr. Pierre FRENDO Professeur, INRA UNS CNRS Sophia-Antipolis Président Dr. Marc-Henri LEBRUN Directeur de Recherche, INRA AgroParis Tech Grignon Rapporteur Dr. Nemo PEETERS Directeur de Recherche, CNRS-INRA Castanet Tolosan Rapporteur Dr. Stéphane JOUANNIC Chargé de Recherche, IRD Montpellier Examinateur Dr. Bruno FAVERY Directeur de Recherche, UNS CNRS Sophia-Antipolis Directeur de thèse Doctoral School of Life and Health Sciences Research Unity: UMR ISA INRA 1355-UNS-CNRS 7254 PhD thesis Presented and defensed to obtain Doctor degree in Molecular and Cellular Biology from COTE D’AZUR UNIVERITY by NGUYEN Chinh Nghia Comprehensive Transcriptome Profiling of Root-knot Nematodes during Plant Infection and Characterisation of Species Specific Trait PhD directed by Dr Bruno FAVERY Defense on December 8th 2016 Jury composition : Pr. Pierre FRENDO Professeur, INRA UNS CNRS Sophia-Antipolis President Dr. Marc-Henri LEBRUN Directeur de Recherche, INRA AgroParis Tech Grignon Reporter Dr. Nemo PEETERS Directeur de Recherche, CNRS-INRA Castanet Tolosan Reporter Dr. Stéphane JOUANNIC Chargé de Recherche, IRD Montpellier Examinator Dr. Bruno FAVERY Directeur de Recherche, UNS CNRS Sophia-Antipolis PhD Director Résumé Les nématodes à galles du genre Meloidogyne spp.
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  • Dorylaimida: Nordiidae) from California, with the First Molecular Study and an Updated Taxonomy of the Genus
    animals Article Morphological and Molecular Characterization of Kochinema farodai Baqri and Bohra, 2001 (Dorylaimida: Nordiidae) from California, with the First Molecular Study and an Updated Taxonomy of the Genus Sergio Álvarez-Ortega Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Campus de Móstoles, 28933 Madrid, Spain; [email protected] Received: 16 November 2020; Accepted: 30 November 2020; Published: 4 December 2020 Simple Summary: In this paper, a population of a free-living nematode collected from Northern California (USA) is identified and studied. The aim of the present work is to characterize a Californian population of the nematode genus Kochinema, with morphological and molecular methods. In addition, a revision of this genus is also provided including an updated diagnosis, a list of species, a key to species identification, and a compendium of their main morphometrics and distribution data. Abstract: This paper deals with the morphological and molecular characterization of Kochinema farodai Baqri and Bohra, 2001, with an integrative approach. The finding of K. faroidai in California is a remarkable biogeographical novelty, as it is the first American record of the species. Molecular data herein obtained represent the first molecular study of the genus Kochinema. Furthermore, scanning electron microscopy (SEM) observations of a member of Kochinema are provided for the first time. Additionally, this contribution provides new insights into the phylogeny and taxonomy of the nematode genus Kochinema. A brief historical outline of the matter is presented. Then, the morphological pattern of the genus is revised and illustrated, the anterior position of amphids, whose opening is located on lateral lip, being its most relevant diagnostic feature.
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  • The Systematic Position of the Family Ironidae and Its Relation to the Dorylaimida
    THE SYSTEMATIC POSITION OF THE FAMILY IRONIDAE AND ITS RELATION TO THE DORYLAIMIDA by A. COOMANS and A. VAN DER HEIDEN Instituut voor Dierkunde, Rijksuniversiteit Gent, Ledeganckstraat 35, B 9000 Gent, Belgium ABSTRACT A critical review is made of the similarities and differences existing between the Ironidae and the Dorylaimida. The most important diagnostic features of the main groups of Dorylaimida, up to the superfamily level, and of the Enoplidae are listed. The family Ironidae is subdivided into two subfamilies of which the Coniliinae constitute a new subfamily with Conilia Gerlach, 1956 as the type genus. From the detailed comparison of both groups it is concluded that the differences are important and that the similarities are probably the result of parallel evolution, occurring in two branches that evolved independently from a remote enoplid ancestor. It is further argued that Ironidae do not fit well in Tripyloidea and are at present better included in Enoploidea, On several occasions the similarities between Ironidae and Dorylaimida have been stressed, the extreme being the inclusion of the genera of the Ironidae in the family Dorylaimidae (W ie s e r , 1953). Ironidae are now usually classified under Tripyloidea in the Enoplida, but a close relationship between Ironidae and Dory­ laimida has been postulated, with Ironidae representing the ancestral type. COMPARISON OF THE MAIN FEATURES OF IRONIDAE AND DORYLAIMIDA Differences can be observed in e.g. the number and position of the lips (except Ironella), structure and outlet of the excretory system, position of the oesophageal gland outlets and habitat of most representatives. Similarities exist in general body shape, position and shape of the amphideal fovea, structure of the feeding apparatus, structure of the female reproductive system and of the male copulatory apparatus.
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  • Two New Species of Xiphinema Cobb, 1913 (Nematoda, Dorylaimida) From
    Bull. Mus. natn. Hist. nut., Paris, 4e sér., 5, 1983, section A, no 2 : 521-529. Two new species of Xiphinema Cobb, 1913 (Nematoda, Dorylddda) from Malawi, East Africa by D. J. F. BROWN,M. Luc and V. MT. SAIEA Abstract. -- Descriptions are given of Xiphinema malawiense n. sp. and X. limbeense n. sp., both from the same location, from the rhizosphere of Citrus paradisi Marfad, at the Bvumbwe Agricultural Research Station, Limbe, Malawi. Both species were without males and were mor- phologically similar to each other and to X. coxi Tarjan, 1964. But they may be distinguished from each other and from the latter species by tail length and shape, spear length, and, mainly, by structures of the pseudo Z organ. Résumé. -- Description est donnée de Xiphinema malawiense n. sp. et de X. limbeense n. sp., provenant l'une et l'autre de la rhizosphere de Citrzis paradisi Marfad, sur la Station de Recherches Agricoles de Bvumbwe, à Limbe, Malawi. Les deux espèces, dont les mâles n'ont pas été trouvés, sont proches l'une de l'autre, et proches également de X. coxi Tarjan, 1964. Elles diffèrent entre elles, et de cette dernière espèce, par la forme et la longueur de la queue, la longueur du stylet et, principalement, par la structure du pseudo-organe Z. D. J. F. BROWN,Scottish Crop Research Institute, Inoergowrie, Dundee, U.K. M. Luc, Nématologiste de I'ORSTOM : Laboratoire des Vers associé au CNRS, 61, rue Buffon, 'i5231 Paris cedex 05. V. W. SAKA,Bvumbwe Agricultural Research Station, P. O. Box 67/34, Limbe, Malawi.
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  • Nematoda, Dorylaimida)
    Nematol. mediI. (1987), 15: 103-109. Istituto di Nematologia Agraria, C.N.R. - 70126 Bari, Italy and The International Potato Center - Lima, Peru A REPORT OF SOME XIPHINEMA SPECIES OCCURRING IN PERU (NEMATODA, DORYLAIMIDA) by F. LAMBERTI, P. JATALA and A. AGOSTINELLI! Records of species of Xiphinema Cobb from Peru are occasional and infrequent (Tarjan, 1969; Jatala, 1975; Lamberti and Bleve-Zacheo, 1979). In the nematode collection of the International Potato Center (CIP) in Lima, Peru, there are specimens belonging to this genus, collected in the past by one of us (J atala). An examination of the slide collection revealed the presence of species still unreported from this country. The morphometrics of some females were studied and are commented on here. Nematodes were fixed with 5% hot formalin and mounted in anhydrous glycerin. Xiphinema brasiliense Lordello, 1951 occurred in the rhizosphere of mango trees (Mangifera indica L.) in San Ramon, the Jungle area. The morphometrics of this mono delphic species (only the posterior gonad is present) are as follows: n=3 9 9; L=2 (1.99-2.02) mm; a=34 (32-36); b=4.7 (4.4-5); c=59 (53-65); c'=0.9 (0.9-0.98); V=30 (29-30); odontostyle= 137 (135-139) pm; odontophore=76 (74-78) ~m; oral aperture to guiding ring= 128 (127-129) pm; taillength=34 (31-37) ~m. The peruvian specimens of X. brasiliense (Fig. 1, a and b) do not differ morphologically from the original description (Lordello, 1951) based on specimens from the State of Sao Paulo, Brazil, with the value of the c ratio as amended by Sturhan (1963).
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  • Xiphinema Americanum Sensu Lato
    EPPO quarantine pest Prepared by CABI and EPPO for the EU under Contract 90/399003 Data Sheets on Quarantine Pests Xiphinema americanum sensu lato IDENTITY • Xiphinema americanum sensu lato Name: Xiphinema americanum Cobb sensu lato Synonyms: Tylencholaimus americanus (Cobb) Micoletzky Taxonomic position: Nematoda: Longidoridae Common names: American dagger nematode (English) Notes on taxonomy and nomenclature: For some time the designation of X. americanum has been disputed. Tarjan (1969) considered that X. americanum was a single species with large intraspecific variation, whereas Lima (1968) argued for a species complex containing seven species. Lamberti & Bleve-Zacheo (1979) divided the species into 15 new species and believed that at least 25 species could be recognized as belonging to the species complex. Current opinion puts the number of species at more than 40, one of which is X. americanum sensu stricto. However, the differences between several described species are small, while there is little information on intraspecific variability. For these reasons, and because the illustrations of many of the species are poor, few taxonomists would claim to be able to separate the species with certainty. An international group of taxonomists, under the auspices of EPPO, is currently making a morphological study of the species complex to try to clarify the relationships within it. Other research is directed towards the use of genetic techniques to distinguish species (Vrain et al., 1992). In the meantime, it is difficult to interpret most of the published data on the distribution, host/parasite relationships and virus-vector abilities of the component species. This data sheet considers X. americanum sensu lato, the species complex as a whole.
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  • The Longidoridae (Nematoda: Dorylaimida) in Yugoslavia. I
    Nematol. medit. (1989), 17: 97-108 Institute 0/ Biology, Faculty 0/ Science, University 0/ Novi Sad, 21000 Novi Sad, Yugoslavia THE LONGIDORIDAE (NEMATODA: DORYLAIMIDA) IN YUGOSLAVIA. I by L. BARS] Summary. A preliminary survey of longidorid nematodes was carried out in some regions of Yugoslavia. Four species of Longidorus: L. distinctus, Lamberti, Choleva et Agostinelli, 1983; L. euonymus Mali et Hooper, 1973; L. juvenilis Dalmasso, 1969 and L. macrosoma Hooper, 1961 and nine species of Xiphinema: X. brevicolle Lordello et Da Costa, 1961; X. dentatum Sturhan, 1978; X. diversicaudatum (Micoletzky, 1927) Thorne, 1939; X. incertum Lamberti, Choleva et Agostinelli, 1983; X. index Thorne et Allen, 1950; X. italiae Meyl, 1953; X. pachtaicum (Tulaganov, 1938) Kirjanova, 1951; X. vuittenezi Luc, Lima, Weischer et Flegg, 1964 and Xiphinema sp. were found. L. distinctus, L. euonymus, L. juvenilis and X. incertum are recorded for the first time from Yugoslavia. Morphological characteristics, morphometrics and distribution of the species are presented. The occurrence and geographical distribution of longi­ and Xiphinema sp. were found. Their geographical distri­ do rid nematodes in Yugoslavia have been referred to in bution is indicated on Figs. 1 and 2. several publications (Krnjaic, 1968, 1970, 1976, 1976a; Hdic, 1973, 1978; Lamberti et al., 1973; Krnjaic et al., 1976; Lamberti et al., 1976; PejCinovski, 1984; Ivezic, LONGIDORUS DlSTINCTUS 1985; Ivezic et al., 1985; Barsi and Horvatovic, 1986). Lamberti, Choleva et Agostinelli, 1983 This paper
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  • Longidoridae (Nema Toda: Dorylaimida) from Sudan
    Nematol. medito (1989), 19: 177-189 lnstituut voor Dierkunde, Ri;ksuniversiteit Gent 9000 Gent, Belgium LONGIDORIDAE (NEMA TODA: DORYLAIMIDA) FROM SUDAN by A.B.ZEIDAN* and A. COOMANS Summary. Five speciesof Longidoridae belonging to the genera Longidorus and Xiphinema were found, described and illustrated, i.e., Longidorus africanus, L. pisi, Xiphinema basiri, X. elongatum and X. simillimum. All speciesare recorded far the second rime tram Sudano L. africanus possessesa small amphidial aperture, appearing as a minute slit both under light microscope and SEM. Five species belonging to the genus Longidorus bave = 97 % 8 (83-105),b = 10.5 % 0.9 (9.4-12.3), c = 88 % previously been reported from Sudan, namely: L. africanus lO (81-105), c' = 1.7 % 0.1 (1.5-1.9), V % = 49 % 1 Merny, 1966; L. siddiqii Aboul-Eid, 1970 (now L. pisi Ed- (48-51);tail = 47 IJ.m% 4 (40-53);odontostyle = 88 IJ.m ward, Misra et Singh, 1964); L. laevicapitatusWilliams, % 3 (82-92); odontophore = 41IJ.m % 3 (38.,48);stylet = 1959; L. brevicaudatusSchuurmans Stekhoven, 1951 and 129 IJ.m % 3 (124-133). Longidorus sp. (Yassin, 1967, 1972, 1974, 1975, 1986; Yassin et al., 1971; Elamin and Siddiqi, 1970; Decker et Males: not found. al., 1980). Five Xiphinema species bave also been reported from Juveniles: Sudan, i.e., X. basiri Siddiqi, 1959; X. ebriense1uc., 1958; J1 (n = 4): L = 1.20 mm (1.17-1.24), a = 61 (55-63), X. elongatum Schuurmans Stekhoven et Teunissen, 1938; b = 5.1 (4.8-5.2), c = 30 (28-32), c' = 2.8 (2.6-3.0); tail X.
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  • The Xiphinema Americanum Group (Nematoda : Dorylaimida)
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Horizon / Pleins textes Fundam. appl. NemalOl., 1993,16 (4),355-358 The Xiphinema americanum group (Nematoda : Dorylaimida). 1. Comments upon the key to species published by Lmnberti and Carone (1992) Pieter A. A. Loof *, Michel Luc ** and August COOMAi'Js *** *' Nematology Department, Agricultuml University, P. 0. Box 8123, 6700 ES Wageningen, Netherlands; ** Muséum National d'HistoiTe Naturelle, Laboratoire de Biologie Parasitaire, Protistologie, Helminthologie, 61, rue de Buffon, 75005 Paris, France and *** lnstituut voor Dierkunde, Universiteit Gent, Ledeganckstraat 35, 9000 Gent, Belgium.. Accepted for publication 9 December 1992. Summary - The theoretica1 and practical shortcomings of the key to the Xiphinema amen'canum group published by Larnberti and Carone (1992) are pointed out, and sorne suggestions are given ta irnprove the possibiJities of identifying species in this group. Résumé - Le groupe Xiphinema americanum (Nernata: Dorylaimida). 1. Commentaires sur la clé des espèces publiée par Lamberti et Carone (1992) - Les défauts, théoriques et pratiques, de la clé de détermination des espèces du groupe Xiphinema americanum, clé publiée par Lamberti et Carone (1992), sont relevés par les auteurs et des suggestions énoncées visant à améliorer les possibilités d'identification spécifique dans ce groupe. Key-words : Xiphinema, X. americanum-group, specifie identification. Loof and Luc (1990) pointed out that no comprehen­ Theoretical shortcomings
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