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Sergei A. Subbotin

Summary

Rapid diagnosis tools for detection of root-knot nematodes play an important role in the disease control and eradication programme. Recombinase polymerase amplification (RPA) assays were developed targeting the IGS rRNA gene of the pacara earpod tree root-knot nematode, Meloidogyne enterolobii. The RPA assays using TwistAmp® Basic and TwistAmp® exo kits allowed detection of M. enterolobii from gall tissues and crude nematode extracts of all stages of target species without a DNA extraction step. The results of real-time RPA assays using a real-time fluorescent detection of a series of crude nematode extracts showed reliable detection with sensitivity of 1/10 of a second-stage juvenile in a RPA reaction tube after 15-20 min. The RPA assay provides affordable, simple, fast and sensitive detection of M. enterolobii.

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David J. Hunt and Sergei A. Subbotin

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J.J. Chitambar and Sergei A. Subbotin

The sheath nematodes belonging to the superfamily Hemicycliophoroidea are unique amongst all plant parasitic nematodes known to man due to the presence of an extra cuticular covering or sheath over the inner cuticle and body of all juvenile and adult life stages. These plant-parasitic nematodes include species of agricultural and quarantine importance.
In Systematics of the Sheath Nematodes of the Superfamily Hemicycliophoroidea John Chitambar and Sergei Subbotin provide a detailed review of the taxonomy and diagnosis of the superfamily, its member genera and 153 related species based on their morphological and molecular analyses, as well as a further understanding of the relationships within the superfamily using molecular phylogenetics. In addition, Chitambar and Subbotin also give detailed information on the global distribution, biology, host-parasite relationships and ecology of sheath nematodes.
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Sergei A. Subbotin, Mundo-Ocampo and J. Baldwin

Volume 8 in the series, appearing in two parts, A and B, deals with the systematics of cyst nematodes of the subfamily Heteroderinae. Cyst nematodes are important pathogens causing extensive damage and significant yield loss to many crops in both temperate and tropical regions. Part A presents summarised information on various aspects of morphology, biology, ecology, pathology, biogeography, control measures and diagnostics of these nematodes. Molecular diagnostic tables and comprehensive tabular and dichotomous keys for species identification, together with descriptions of protocols for extraction, light and electron microscopy studies, and molecular diagnostics are also included. The taxonomic section of part A provides diagnoses for six genera, viz., Globodera, Punctodera, Cactodera, Dolichodera, Betulodera and Paradolichodera, and includes descriptions and morphometrics of 30 valid species. The work is illustrated by 101 drawings and photos. The genus Heterodera is mainly covered in part B, complete descriptions and morphometrics of the 80 known valid species being provided and the species illustrated by 159 line drawings and photos. Identification of the species using morphological and molecular techniques is also covered. Each part includes an extensive bibliography.
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Series:

Sergei A. Subbotin, Mundo-Ocampo and J. Baldwin

Volume 8 in the series, appearing in two parts, A and B, deals with the systematics of cyst nematodes of the subfamily Heteroderinae. Cyst nematodes are important pathogens causing extensive damage and significant yield loss to many crops in both temperate and tropical regions. Part A presents summarised information on various aspects of morphology, biology, ecology, pathology, biogeography, control measures and diagnostics of these nematodes. Molecular diagnostic tables and comprehensive tabular and dichotomous keys for species identification, together with descriptions of protocols for extraction, light and electron microscopy studies, and molecular diagnostics are also included. The taxonomic section of part A provides diagnoses for six genera, viz., Globodera, Punctodera, Cactodera, Dolichodera, Betulodera and Paradolichodera, and includes descriptions and morphometrics of 30 valid species. The work is illustrated by 101 drawings and photos. The genus Heterodera is mainly covered in part B, complete descriptions and morphometrics of the 80 known valid species being provided and the species illustrated by 159 line drawings and photos. Identification of the species using morphological and molecular techniques is also covered. Each part includes an extensive bibliography.
No Access

Series:

Sergei A. Subbotin, Mundo-Ocampo and J. Baldwin

Volume 8 in the series, appearing in two parts, A and B, deals with the systematics of cyst nematodes of the subfamily Heteroderinae. Cyst nematodes are important pathogens causing extensive damage and significant yield loss to many crops in both temperate and tropical regions. Part A presents summarised information on various aspects of morphology, biology, ecology, pathology, biogeography, control measures and diagnostics of these nematodes. Molecular diagnostic tables and comprehensive tabular and dichotomous keys for species identification, together with descriptions of protocols for extraction, light and electron microscopy studies, and molecular diagnostics are also included. The taxonomic section of part A provides diagnoses for six genera, viz., Globodera, Punctodera, Cactodera, Dolichodera, Betulodera and Paradolichodera, and includes descriptions and morphometrics of 30 valid species. The work is illustrated by 101 drawings and photos. The genus Heterodera is mainly covered in part B, complete descriptions and morphometrics of the 80 known valid species being provided and the species illustrated by 159 line drawings and photos. Identification of the species using morphological and molecular techniques is also covered. Each part includes an extensive bibliography.
No Access

Reza Ghaderi, Akbar Karegar, Gholamreza Niknam and Sergei A. Subbotin

Sixteen species, Amplimerlinius globigerus, A. macrurus, Bitylenchus parvus, Merlinius brevidens, M. nanus, Neodolichorhynchus phaseoli, Paramerlinius neohexagrammus, Pratylenchoides alkani, P. ritteri, P. utahensis, Scutylenchus paniculoides, S. rugosus, S. tartuensis, Scutylenchus sp. A, Trophurus impar and Tylenchorhynchus brassicae, from the families Telotylenchidae and Merliniidae were collected from different locations in Iran and molecularly characterised using sequencing of the D2D3 expansion fragments of the 28S rRNA gene. Morphometrics and light micrography for studied species are also provided as vouchers. The phylogenetic relationships of Telotylenchidae and Merliniidae with other representatives of the order Tylenchida, as obtained from Bayesian inference and Maximum likelihood analysis of partial 28S rRNA gene sequences, are presented and discussed. The results of phylogenetic analysis were in accordance with classifications in which Bitylenchus and Scutylenchus are considered as separate genera, but Tessellus and Telotylenchus were synonyms of Tylenchorhynchus. The Shimodaira-Hasegawa test of the 28S rRNA gene sequence alignment and trees rejected a large genus concept of Tylenchorhynchus and the constrained monophyly for Belonolaimidae revealed within this family two genera groups: iBelonolaimus and Ibipora; and iiCarphodorus and Morulaimus. The present results also support the combination of Pratylenchoides and Merliniinae into a single family, the Merliniidae.

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Esther van den Berg, Louwrens R. Tiedt and Sergei A. Subbotin

During recent collections in South Africa, two species of Criconemoides were found. Criconemoides brevistylus is described and illustrated from a golf course in KwaZulu-Natal Province. It is compared with several closely related species, and three previously described species (C. helicus, C. onostris and C. paronostris) are regarded as junior synonyms of C. brevistylus. Criconemoides obtusicaudatus is described and illustrated from a maize field in Limpopo Province. The male of the species is described for the first time. Molecular characterisation of C. brevistylus and C. obtusicaudatus using the D2-D3 expansions segments of 28S rRNA and ITS rRNA gene sequences are provided. Phylogenetic relationships of these species with other Criconemoides are discussed.

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Sergio Álvarez-Ortega, Sergei A. Subbotin and Reyes Peña-Santiago

This contribution presents a study of Iberian and Californian populations of Aporcelaimellus simplex, including morphological, morphometric and molecular data. The species is characterised and distinguished by its lip region offset by an expansion, pars refringens vaginae absent, and conical tail with a small but distinct hyaline terminal portion. No significant difference exists between American and European populations. Molecular data and the derived evolutionary tree show a topology in which this species forms a well-supported group with members of Discolaiminae, far from other representatives of Aporcelaimellus. Putting special emphasis in the absence of pars refringens vaginae, A. simplex is transferred to the genus Aporcella. The taxonomy of this genus is revised in depth, with the proposal of an emended diagnosis, the provision of a list of 13 valid species (mostly new combinations from Aporcelaimellus) as well as a key to their identification and a compendium of their main morphometrics. Aporcella debruinae sp. n. is proposed for Aporcelaimellus papillatus apud de Bruin & Heyns, 1992.