Volume 13, Part 2 (2005)
An evaluation of types of attractants enabling plant-parasitic nematodes to locate plant roots, 83-88.
S.D. Park, Z. Khan, Y.H. Kim.
Damage potential and reproductive fitness of root-knot nematode on some medicinal herbs in Korea, 89-94.
N.P. Fadeeva, I.L.Davydkova. Some aspects of the life history and ecology of Oncholaimium ramosum (Nematoda : Oncholaimidae) in the polluted harbour of the Sea of Japan, 95-105.
J. Liao, W. Yang, Z. Feng, G. Karseen.
Description of Meloidogyne panyuensis sp. n. (Nematoda: Meloidogynidae), parasitic on peanut (Arachis hypogaea L.) in China, 107-114.
L. Jiang, J. Zheng, L. Waeyenberge, S.A. Subbotin, M. Moens.
Duplex PCR based identification of Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle, 1970, 115-121.
D. Sturhan, C.N. Nguyen. Occurrence and hosts of nematode-parasitic bacteria of the genus Pasteuria in Vietnam, 123-129.
H. Talvik, W. Sudhaus, E. Moks, G. Liivla, E. Krall. The saprobiotic nematode Pelodera strongyloides dermatitica (Rhabditida : Rhabditidae) as a cause of dermatitis in Labrador retriever, 131-135.
T.V. Rubtsova, M. Moens, S.A Subbotin. PCR amplification of a rRNA gene fragment from formalin-fixed and glycerine-embedded nematodes from permanent slides, 137-140.
- Abstract of the Sixth English Language International Symposium of the Russian Society of Nematologsts (Moscow, 13th-17th, 2005), 141-168
- Book Review, 169-172
- Newsletter of the Russian Society of Nematologists
An evaluation of types of attractants enabling plant-parasitic nematodes to locate plant roots
The ability of plant-parasitic nematodes to orientate towards stimuli from plant roots enhances the chances of host location. This brief review examines the attractants involved in terms of their spatial attributes. Several gradients exist around physiologically active roots and it is probable that some constitute 'long distance attractants' that enable nematodes to migrate to the root area. Attractants that cause nematodes to move to individual roots may be termed 'short distance attractants' and there is evidence that, in some instances, the attractiveness of a host to the pest species is correlated with its efficiency as a host. The orientation of second-stage juveniles of endoparasitic nematodes to the preferred invasion site, the root tip, is well established but the cues that constitute the associated 'local attractants' are Unknown. The types of attractants are discussed briefly in the context of plant physiology and the root environment.
Key words: attractants, root attraction, root diffusates, semiochemicals, sensory responses.
Park, S.D., Khan, Z. and Kim, Y.H..
Damage potential and reproductive fitness of root-knot nematode on some medicinal herbs in Korea
The damage potential and reproduction of root-knot nematodes, Meloidogyne hapla oil medicinal herbs, Angelica dahurica, Codonopsis pilosula and Glycyrrhiza uralensis , was tested in potted soil under glasshouse conditions. Three-week-old seedlings were inoculated with initial population densities (Pi) of 1000, 2000, 3000, 4000 and 5000 second-stage juveniles (J2)/plant. Significant damage was observed oil shoot and root lengths, fresh root weight and root diameter of A. dahurica, C pilosula and G. uralensis by all Pi levels 90 day post-inoculation. Damage increased with increase in Pi. 5000 Pi caused 31.7, 34.0 and 25.2% reduction in root lengths of A. dahurica, C. pilosula and G. uralensis , respectively. Higher root galling index was observed oil A. dahurica than oil C. pilosula and G. uralensis at all Pi levels. At the highest Pi, root gall index was 5.0, 4.2 and 3.8 on A. dahurica, C pilosula and G. uralensis , respectively. Increasing rate of Pi exponentially reduced reproduction factor (Rf) of M. hapla oil all the three species of medicinal herbs. However, the Rf was higher oil A. dahurica than oil C. pilosula and G. uralensis at all Pi levels.
Key words: Angelica dahurica, Codonopsis pilosula, Glycyrrhiza uralensis, Korea, medicinal plants, Meloidogyne hapla, pathogenicity.
Fadeeva, N.P. and Davydkova, I.L.
Some aspects of the life history and ecology of Oncholaimium ramosum (Nematoda : Oncholaimidae) in the polluted harbour of the Sea of Japan
Oncholaimium ramosum (Nematoda: Oncholaimidae) occurs in the heavily polluted harbours of the Sea of Japan. The life history of O. ramosum has been studied in the laboratory and in the habitat over a two-year period. Observations on the embryonic and postembryonic development, and also the moulting processes are presented. Egg laying was observed on 35 occasions, and 400 eggs and approximately 1000 nematodes of this species were investigated. O. ramosum has two generations in the Sea of Japan. Egg deposition continues from February to July (spring generation) and from September to November (autumn generation). Females of O. ramosum were observed from egg deposition to death. Eggs are laid either singly or in batches of 2-38. The cleavage of 43-50% of eggs was observed immediately after eggs had been laid. The development of the remaining eggs was delayed for 8-10 days. The process of hatching of the first to last egg to be laid also occurred over 8-10 days. The stages of 2, 4, 8 blastomeres, late gastrula, and vermiform juveniles are described. The average time of development of O. ramosum from the beginning of cleavage to hatching was 1-1.5 months. The size and developmental time of O. ramosum juveniles (J1-J4) and adults was determined. Reproduction and duration of the life cycle are discussed.
Key words: free-living marine nematodes, embryonic, postembryonic development, Sea of Japan.
Liao, J. Yang, W., Feng, Z. and Karseen, G.
Description of Meloidogyne panyuensis sp. n. (Nematoda: Meloidogynidae), parasitic on peanut (Arachis hypogaea L.) in China
Meloidogyne panyuensis sp. n. is described and illustrated from peanut, Arachis hypogaea L., in Guangdong, P.R.China. It is characterized by: female stylet of 13 Ám length, DGO of 10 Ám; perineal pattern ovoid to oval shaped, smooth to moderately coarse striae, dorsal arch relatively low, lateral lines indistinct, tail terminus area with irregular striae; male stylet 24 pin long; labial disc oval shaped, slightly elevated and fused with crescent shaped medial lips, second-stage juveniles with small rounded labial disc, fused with medial lips, lateral field with four incisures, areolated; tail 55 pill long, gradually tapering towards a small pointed terminus, hyaline tail part distinct. A weak S1-F1 esterase pattern and a Nib malate dehydrogenase pattern were obtained front young single females. Additionally, distinguishing DNA information is presented.
Key words: Arachis hypogaea, Meloidogyne panyuensis sp. n. morphology.
Jiang, L., Zheng, J., Waeyenberge, L., Subbotin, S.A. and Moens, M.
Duplex PCR based identification of Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle, 1970
A duplex PCR combining species-specific primers and universal primers was developed to identify Bursaphelenchus xylophilus. The design of the specific primers was based on differences in the Internal Transcribed Spacer sequences of rRNA between Bursaphelenchus xylophilus and other Bursaphelenchus species. The method was validated using 24 populations of different Bursaphelenchus spp. and four other nematode species. The duplex PCR generated a specific amplicon of 580 bp for all populations of B. xylophilus and a control amplicon, obtained after amplification of D2-D3 expansion fragments of the 28S rRNA gene, of about 770 bp. All non B. xylophilus samples generated only the 770 bp fragment. Compared to other molecular methods, duplex PCR is more rapid, reliable and cheaper. It allows the detection of single specimen of B. xylophilus in a sample.
Key words: Bursaphelenchus xylophilus, B. mucronatus, diagnostics, duplex PCR, species-specific primer, rRNA.
Sturhan, D. and Nguyen, C.N.
Occurrence and hosts of nematode-parasitic bacteria of the genus Pasteuria in Vietnam
Nematodes in 74 of a total of 132 soil samples from forests and sortie agricultural and coastal sites in various parts of Vietnam were found to be attacked by Pasteuria. Among 123 host records, the majority were members of the order Tylenchida (with members of Heteroderidae, Helicotylenchus spp. and Meloidogyne spp. predominating), followed by Dorylaimida. Many of the nematode taxa are reported as hosts for Pasteuria for the first time. lit almost half of the samples with Pasteuria several different nematode taxa were simultaneously attacked by the bacterial parasites. Differences in dimensions and other morphological characteristics of the sporangia and endospores observed in various]lost nematodes indicate that several Pasteuria species are present in Vietnam. Their role as antagonists of plant-parasitic and other soil-inhabiting nematodes is still unknown.
Key words: agriculture, bacteria, coast, forest, hosts, nematodes, parasites, Pasteuria, soil, Vietnam.
Talvik, H., Sudhaus, W., Moks, E., Liivla, G. and Krall, E.
The saprobiotic nematode Pelodera strongyloides dermatitica (Rhabditida : Rhabditidae) as a cause of dermatitis in Labrador retriever
Pelodera strongyloides (Nematoda: Rhabditida) is a free-living saprobiotic nematode that inhabits dung and decaying organic matter. There are reports of skill invasions by the third-stage juveniles of P. strongyloides in dogs, some other mammals and even humans. A 6-year-old female Labrador Retriever showed signs of severe papulous dermatitis and alopecia oil the front, lateral thorax and abdomen and oil the outer sides of the thighs. The dog suffered from severe pruritus. Alive rhabditoid nematodes were found from skin scrapings. Juveniles were cultured oil NGM agar and numerous free-living females and somewhat fewer male worms were obtained and identified as Pelodera strongyloides dermatitica. Juveniles of this particular strain, although aberrant invaders of dog's skill, show adaptations towards a parasitic mode of life. The biology of this subspecies and related species is discussed. The present case is the first documented finding of P. strongyloides dermatitica in Estonia.
Key words: Pelodera strongyloides dermatitica, dermatitis, domestic dog, Estonia, infective larvae.