USD $319.00
Search Results
Author:
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.
In:
Nematology
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.
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.
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.
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.
Summary
Molecular characterisation of two species of Meloinema: M. chitwoodi from Oregon, USA, and M. odesanens from South Korea, is given based on the partial 18S rRNA, the D2-D3 of 28S rRNA, ITS rRNA, and COI gene sequences. In the phylogenetic trees, Meloinema clustered with Meloidogyne, in a basal position and more closely with Meloidogyne indica and M. nataliei. The Shimodaira-Hasegawa (SH) maximum likelihood testing of an alternative topology with two gene fragments (D2-D3 of 28S rRNA and 18S rRNA genes) did not reject a sister relationship of Meloidogyne and Meloinema. Molecular results confirmed the view of Siddiqi (2000) that Meloidogyne and Meloinema evolved from a Pratylenchidae-type ancestor. The clade Meloinema + Meloidogyne + Nacobbus was rejected by the SH test of the D2-D3 of 28S rRNA gene sequence dataset. The molecular results suggested that the genus Nacobbus should be placed not in the Meloidogynidae, but in a separate subfamily, the Nacobbinae, under the family Pratylenchidae.
In:
Nematology
Summary
During surveys for stubby root nematodes in the natural vegetation of California, Oregon and Washington, USA, three known species, viz., Trichodorus californicus, T. intermedius and T. obscurus were recovered together with ten unidentified Trichodorus species. The three known and one new species were studied using an integrated approach. Trichodorus pseudoaequalis n. sp. is characterised by a medium-sized body about 800 μm long on average, male with two ventromedian cervical papillae anterior to secretory-excretory pore and three precloacal supplements all located anterior to the retracted spicules; spicules 39 μm long (average), slightly ventrally curved, more so in head region and blade with slight indentation mid-way and striation more pronounced in posterior half. Females possess a rather short (average 33% of corresponding body diam.) pear-shaped vagina with small vaginal sclerotised pieces (ca 1.5 μm long), rounded triangular in shape, obliquely orientated and close together; one pair of sublateral body pores anterior (about four vulval body diam.) to vulva and one pair of post-advulvar sublateral body pores. Trichodorus pseudoaequalis n. sp. differs from the most similar species, T. aequalis, in male characters like general spicule shape and ornamentation and in the position of the dorsal pharyngeal gland nucleus in both sexes (at same level of posterior ventrosublateral pair vs clearly separated). The phylogenetic relationships of the recovered species were reconstructed using the ITS2 rRNA and the D2-D3 expansion segments of 28S rRNA gene sequences.
In:
Nematology
Summary
Two new species of the genus Meloidodera collected in Mexico are described here: M. ferrisi sp. n. parasitising roots of an oak tree in the State of Mexico and M. tecoacensis sp. n. parasitising roots of buffalo bur nightshade in the Tlaxcala State. Meloidodera ferrisi sp. n. is characterised by a spherical female body covered completely by a dark thick cuticular layer, length/width of the female body = 0.8-1.6, stylet = 35-43 μm and second-stage juvenile with average body = 340 μm and average tail length = 35.6 μm. Meloidodera tecoacensis sp. n. is characterised by the female having a spherical body covered with a yellow transparent material, length/width of the female body = 1.1-2.8, stylet = 20-33 μm and second-stage juvenile with average body = 340 μm and average tail length = 29.8 μm. These two species were molecularly characterised using the D2-D3 expansion segments of 28S rRNA, ITS rRNA and COI gene sequences. Phylogenetic analysis revealed that the two new species represent a separate evolutionary lineage within the subfamily Meloidoderinae. An identification key for 12 Meloidodera species is provided.
In:
Nematology
Summary
The pigeon pea cyst nematode, Heterodera cajani, is an important nematode pest of pigeon pea that is present in all major growing regions of this crop in India and reported from Pakistan, Egypt and Myanmar. In this study, a new real-time PCR assay for detection of H. cajani using a species-specific primer and a TaqMan probe was developed. The primers and a probe were designed to amplify the COI gene fragment. The specificity of the primer-probe set was tested in singleplex or multiplex reactions against target and non-target nematodes. In multiplex real-time PCR experiments with the specific and universal primer-probe sets, the signals were simultaneously observed for COI and D3 of 28S rRNA target genes. The results showed that the real-time PCR assay with species-specific primer and probe was sensitive enough to detect H. cajani DNA extracted from 0.003 egg or second-stage juvenile.
In:
Nematology