Return to the Russian Journal of Nematology Home page

Volume 9, Part 1 (2001)

Phan, K.L., Nguyen, N.C. and Moens, M.

Steinernema sangi sp. n. (Rhabditida: Steinernematidae) from Vietnam

A description is given of Steinernema sangi sp. n. that was isolated from soil in Thanhhoa province in the northern part of Vietnam. The lateral field of infective juveniles (IJ) has eight ridges with the submarginal and central pair less distinct, and this characteristic makes S. sangi sp. n. most similar to S. kraussei. However, S. sangi sp. n. can be distinguished from S. kraussei by the shorter body length of the IJ (753 vs 951 mm), a more anterior position of the excretory pore of the IJ (51 vs 63 mm) and a longer spicule length (63 vs 49 mm). Steinernema sangi sp. n. can be distinguished from S. kraussei by RFLP patterns obtained after digestion of the ITS region by each of the enzymes: AluI, CfoI, DdeI, EcoRI, HaeIII, MspI, NdeII, RsaI, and SalI.

Key words: entomopathogenic nematodes, RFLPs, Steinernema sangi sp. n., taxonomy, Vietnam.

Eroshenko, A.S., Subbotin, S.A. and Kazachenko, I.P.

Heterodera vallicola sp. n. (Tylenchida: Heteroderidae) from elm trees, Ulmus japonica (Rehd.) Sarg. in the Primorsky territory, the Russian Far East, with rDNA identificat1ion of closely related species

Heterodera vallicola sp. n. is described from the rhizosphere and roots of elm plants Ulmus japonica (Rehd.) Sarg. (Ulmaceae Urticales), growing in a forest along the Ilistaija river in the Mikhailovsky district, Primorsky region, the Russian Far East. This species belongs to the Humuli group. It differs from H. riparia by its more rounded cysts, narrower semifenestral width, longer length stylet and longer hyaline part of tail for the second stage juveniles. It can be distinguished from H. humuli by having a shorter fenestral length, and smaller body length females and males. Restriction enzyme analysis of the ITS regions of ribosomal DNA obtained with AluI, Alw26I, CfoI, DdeI, PvuII, and RsaI clearly distinguished H. vallicola sp. n. from H. humuli and H. riparia. Phylogenetic relationships of H. vallicola sp. n. with other Humuli group species are given based on analyses of the ITS sequences.

Key words: cyst nematodes, elm, Heterodera fici, H. humuli, H. riparia, ITS of rDNA, phylogeny, RFLP .

Tsalolikhin S.J.

Synopsis of the system of the family Tobrilidae (Nematoda: Enoplida)

Several new species and genera of tobrilids has been described during the previous 20 years, with the taxonomic structure of the family requiring to be changed to include these newly described taxa. Here, a general scheme for tobrilid taxonomy is proposed with acknowledgement that a detailed revision of all of these genera is required. Two principal sets of features are proposed as a basis for tobrilid classification: structure of the stoma, and the presence and position of buccal pockets and teeth that distinguish subfamilies and tribes in the family. The structure of the supplements and the supplementary apparatus are considered to have lesser taxonomic value, being useful only distinguishing genera and subgenera. Species of the genera Tobrilus and Eutobrilus require redescription and possibly some synonymisation, a subject for future study.

Key words:  free-living nematodes, identification key, taxonomy, Tobrilidae.

Ridolfi, M. Patumi, M., D'Addabbo, T., Sasanelli, N. and Lemos, R.J.

Enzymatic response of olive varieties to parasitism by Xiphinema index (Nematoda: Longidoridae)

Phenols content, phenylalanine ammonia lyase (PAL) and peroxidase (POD) activities were determined in leaves and roots of one cultivar (FS-17) and one rootstock (DA-12I) of olive (Olea europaea L.), uninfected and infected by different population densities of Xiphinema index 6 months after inoculation. The role of phenols and peroxidase in the response of olive to feeding by nematodes was confirmed by the experiment. Phenols content and PAL activity were higher in uninfected roots of DA-12I, whereas phenols increased and PAL decreased in the roots of both varieties in relation to the nematode inoculum density. The variation of phenols qualitative profile in the roots of DA-12I suggested a translocation of oleuropein from the leaves to the roots in response to X. index feeding. POD activity increased in roots and leaves of DA-12I, but only in the leaves of FS-17. Analysis of kinetic parameters showed that the same POD isozyme is present in both varieties. 

Key words: scorbic acid, Olea europaea, peroxidase, phenols, phenylalanine ammonia-lyase, resistance, Xiphinema index.

Wouts, W.M., Rumpenhorst, H.J.  and Sturhan, D.

Heterodera betae sp. n., the yellow beet cyst nematode (Nematoda: Heteroderidae)

The yellow beet cyst nematode Heterodera betae sp. n. is described from glasshouse populations originally obtained from a sugar beet field near Karken, Germany and maintained on sugar beet (Beta vulgaris) in Münster and Elsdorf, Germany. The new species resembles species of the Heterodera trifolii complex in the general morphology of the cyst and the shape of the fenestration of the vulval cone. The new species differs from all those species, except H. rosii Duggan & Brennan, 1966, by its longer body and stylet and the more robust stylet knobs of the infective juveniles. It differs from H. rosii in that it infects sugar beet, and has no males. Heterodera betae can be distinguished from its close relative H. trifolii Goffart, 1932, by RFLPs of the ITS regions of the rDNA obtained after amplification with the primers F194 and F195, and digestion with the enzymes ScrFI, MvaI and PvuII.

Key words: Beta vulgaris, Chenopodiaceae, Cruciferae, description, Germany, Leguminosae, Netherlands, new species, rDNA.

Sturhan, D. and Loof, P.A.A.

Redescription of Longidorus poessneckensis Altherr, 1974 (Nematoda: Dorylaimida)

Longidorus poessneckensis Altherr, 1974, originally described from specimens from Thuringia, Germany, was recently discovered at several sites in the central part of Germany, and at one site in Slovakia. On the basis of this material the species is redescribed, including all four juvenile stages. Males were not found. Longidorus poessneckensis is most similar to L. macrosoma, from which it differs by the shape of the lip region, cuticle structure on the tail end, shape of the J1 tail and absence of males. The species appears to prefer wet soil in forests and river flood-plains.

Key words: description, Germany, Longidorus poessneckensis, morphology, Slovakia, woodland.

Holovachov, O., Boström, S. and Susulovsky, A.

Description of Acroukrainicus sagittiferus gen. et sp. n. (Nematoda: Cephalobidae) from the area of an old sulphur industry in Ukraine

Acroukrainicus sagittiferus gen. et sp. n. from a loamy-sand soil in Ukraine is described on the basis of light and scanning electron microscopy. The new genus is placed in the Cephalobinae and distinguished from all other genera in the subfamily by the possession of three pairs of lips, each lip flat and three-lobed (asymmetrically triangular); primary axils narrow; secondary axils broad; and three pointed labial probolae, each probola shaped as an arrow-head with one rounded lateral tine on each side and a concave abaxial prominence.

Key words: Acroukrainicus sagittiferus, morphology, new genus, SEM, taxonomy, Ukraine.