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A new stem nematode, Ditylenchus oncogenus n. sp. (Nematoda: Tylenchida), parasitizing sowthistle from Adriatic coast dunes in southern Italy

  • N. Vovlas (a1), A. Troccoli (a1), J.E. Palomares-Rius (a2), F. De Luca (a1), C. Cantalapiedra-Navarrete (a2), G. Liébanas (a3), B.B. Landa (a2), S.A. Subbotin (a4) (a5) and P. Castillo (a2)...


Morphological and molecular analyses of a stem nematode causing a severe disease on infected sowthistle (Sonchus bulbosus) plants, involving the formation of gall-like structures on infected leaves and stems, have led to the description of a new species named Ditylenchus oncogenus n. sp. Morphologically, the new species is characterized by a medium to large body size (all adults more than 1 mm in length); a delicate stylet (9.0–11.0 μm long) with minute, rounded knobs; a long post-vulval uterine sac (c. 65% of the vulva–anus distance); six incisures at the lateral fields and characteristic D. destructor-pattern of spicules (with pronounced ventral tumulus and anteriorly pointed, less sclerotized, cuticle parts present within the lamina). The results of molecular analysis of rRNA gene sequences, including the D2–D3 expansion regions of 28S rRNA, internal transcribed spacer (ITS) rRNA, partial 18S rRNA gene, the protein-coding mitochondrial gene, cytochrome oxidase c subunit I (COI), and the heat-shock protein 90 (hsp90) gene, support the new species status. The results of a host-suitability test indicated that the new species does not parasitize potato (Solanum tuberosum) tubers and broad bean (Vicia faba) seedlings. Histopathological observations on naturally infected sowthistle tissues revealed that D. oncogenus n. sp. causes floral stem neoplasia and midrib leaf gall formation on the type, and to date only known, host. The galls were characterized by extensive hyperplasia, where several necrotic cells in the neoplasic area were directly damaged by feeding of the nematode, whereas a number of adjacent cells showed typical cytological changes, such as granulated cytoplasm with hypertrophied nuclei and nucleoli.


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Abolafia, J., Liébanas, G. & Peña-Santiago, R. (2002) Nematodes of the order Rhabditida from Andalucia Oriental, Spain. The subgenus Pseudacrobeles Steiner, 1938, with description of a new species. Journal of Nematode Morphology and Systematics 4, 137154.
Boutsika, K., Brown, D.J.F., Phillips, M.S. & Blok, V.C. (2004) Molecular characterisation of the ribosomal DNA of Paratrichodorus macrostylus, P. pachydermus, Trichodorus primitivus and T. similis (Nematoda: Trichodoridae). Nematology 6, 641654.
Brzeski, M.W. (1991) Review of the genus Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae). Revue de Nématologie 14, 959.
Castillo, P., Vovlas, N., Subbotin, S. & Troccoli, A. (2003) A new root-knot nematode, Meloidogyne baetica n. sp. (Nematoda: Heteroderidae), parasitizing wild olive in Southern Spain. Phytopathology 93, 10931102.
Chizhov, V.N., Borisov, B.A. & Subbotin, S.A. (2010) A new stem nematode, Ditylenchus weischeri sp. n. (Nematoda: Tylenchida), a parasite of Cirsium arvense (L.) Scop. in the central region of the Non-Chernozem zone of Russia. Russian Journal of Nematology 18, 95102.
Coolen, W.A. (1979) Methods for extraction of Meloidogyne spp. and other nematodes from roots and soil. pp. 317329 in Lamberti, F. & Taylor, C.E. (Eds) Root-knot nematodes (Meloidogyne species). Systematics, biology and control. New York, Academic Press.
Darriba, D., Taboada, G.L., Doallo, R. & Posada, D. (2012) jModelTest 2: more models, new heuristics and parallel computing. Nature Methods 9, 772.
Esser, R.P. (1986) A water agar en face view technique. Proceedings of the Helminthological Society of Washington 53, 254255.
Goodey, J.B., Franklin, M.T. & Hooper, D.J. (1965) T. Goodey's The nematode parasites of plants catalogued under their hosts. Farnham Royal, Bucks, England, Commonwealth Agricultural Bureaux.
Gulcu, B., Hazir, S., Gilbin-Davis, R.M., Ye, W., Kanzaki, N., Mergen, H., Keskin, N. & Thomas, W.K. (2008) Molecular variability of Schistonchus caprifici (Nematoda: Aphelenchoididae) from Ficus carica in Turkey. Nematology 10, 639649.
Hall, T.A. (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98NT. Nucleic Acids Symposium Series 41, 9598.
Hooper, D.J. (1986) Handling, fixing, staining and mounting nematodes. pp. 5980 in Southey, J. (Ed.) Laboratory methods for work with plant and soil nematodes. 6th edn. London, Her Majesty's Stationery Office, Ministry of Agriculture, Fisheries and Food.
Huelsenbeck, J.P. & Ronquist, F. (2001) MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics 17, 754755.
Johansen, D.A. (1940) Plant microtechnique. New York, McGraw-Hill.
Karssen, G. & Willemsen, N.M. (2010) The spiculum: an additional useful character for the identification of Ditylenchus dipsaci and D. destructor (Nematoda: Anguinidae). EPPO Bulletin 40, 211212.
Oliveira, R.D.L., Santin, A.M., Seni, D.J., Dietrich, A., Salazar, L.A., Subbotin, S.A., Mundo-Ocampo, M., Goldenberg, R. & Barreto, R.W. (2013) Ditylenchus gallaeformans sp. n. (Tylenchida: Anguinidae) – a neotropical nematode with biocontrol potential against weedy Melastomataceae. Nematology 15, 179196.
Page, R.D. (1996) TreeView: an application to display phylogenetic trees on personal computers. Computer Applications in the Biosciences 12, 357358.
Siddiqi, M.R. (2000) Tylenchida parasites of plants and insects. 2nd edn. Wallingford, UK, CABI Publishing.
Skantar, A.M. & Carta, L.K. (2005) Phylogenetic evaluation of nucleotide and protein sequences from the heat shock protein 90 gene of selected nematodes. Journal of Nematology 36, 466480.
Sturhan, D. & Brzeski, M.W. (1991) Stem and bulb nematodes, Ditylenchus spp. pp. 423464 in Nickle, W.R. (Ed.) Manual of agricultural nematology. New York, Marcel Dekker.
Subbotin, S.A. & Moens, M. (2006) Molecular taxonomy and phylogeny. pp. 3358 in Perry, R. & Moens, M. (Eds) Plant nematology. Wallingford, UK, CABI.
Subbotin, S.A., Vierstraete, A., De Ley, P., Rowe, J., Waeyenberge, L., Moens, M. & Vanfleteren, J.R. (2001) Phylogenetic relationships within the cyst-forming nematodes (Nematoda, Heteroderidae) based on analysis of sequences from the ITS regions of ribosomal DNA. Molecular Phylogenetics and Evolution 21, 16.
Subbotin, S.A., Krall, E.L., Riley, I.T., Chizhov, V.N., Staelens, A., De Loose, M. & Moens, M. (2004) Evolution of the gall-forming plant parasitic nematodes (Tylenchida: Anguinidae) and their relationships with hosts as inferred from Internal Transcribed Spacer sequences of nuclear ribosomal DNA. Molecular Phylogenetics and Evolution 30, 226235.
Subbotin, S.A., Madani, M., Krall, E., Sturhan, D. & Moens, M. (2005) Molecular diagnostics, taxonomy, and phylogeny of the stem nematode Ditylenchus dipsaci species complex based on the sequences of the internal transcribed spacer-rDNA. Phytopathology 95, 13081315.
Swofford, D.L. (2003) PAUP*: Phylogenetic Analysis Using Parsimony (and other methods). 4.0 Beta. Florida State University.
Teploukhova, T.N. (1968) Stem and bulb nematodes (genus Ditylenchus Filipjevi, 1936: family Tylenchidae Örley, 1880) of fauna of USSR and neighbour countries. PhD Thesis, Zoological Institute of the Academy of Science of USSR (in Russian).
Thompson, J.D., Higgins, D.G. & Gibson, T.J. (1994) Clustal W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucleic Acids Research 22, 46734680.
Thorne, G. (1945) Ditylenchus destructor n. sp., the potato root nematode and D. dipsaci (Kühn, 1857), Filipjev, 1936, the teasel nematode. Proceedings of the Helminthological Society of Washington 12, 2733.
Troccoli, A. (2002) Aspetti pratici e comparativi di alcune metodologie tradizionali applicate all'identificazione dei nematodi da quarantena. Nematologia Mediterranea 30, 107110.
Vovlas, N., Troccoli, A., Palomares-Rius, J.E., De Luca, F., Liébanas, G., Landa, B.B., Subbotin, S.A. & Castillo, P. (2011) Ditylenchus gigas n. sp. parasitizing broad bean: a new stem nematode singled out from the Ditylenchus dipsaci species complex using a polyphasic approach with molecular phylogeny. Plant Pathology 60, 762775.
Zhang, S.L., Liu, G.K., Janssen, T., Zhang, S.S., Xiao, S., Li, S.T., Couvreur, M. & Bert, W. (2014) A new stem nematode associated with peanut pod rot in China: morphological and molecular characterization of Ditylenchus arachis n. sp. (Nematoda: Anguinidae). Plant Pathology 63, 11931206.

A new stem nematode, Ditylenchus oncogenus n. sp. (Nematoda: Tylenchida), parasitizing sowthistle from Adriatic coast dunes in southern Italy

  • N. Vovlas (a1), A. Troccoli (a1), J.E. Palomares-Rius (a2), F. De Luca (a1), C. Cantalapiedra-Navarrete (a2), G. Liébanas (a3), B.B. Landa (a2), S.A. Subbotin (a4) (a5) and P. Castillo (a2)...


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