Taxonomy of Tobrilidae species from the Alkaline Lakes of the western Nebraska Sandhills.

Six distinct COI mitochondrial Haplotype Groups (HG) are morphologically, ecologically, and genetically characterized from the aquatic nematode family Tobrilidae. Collection locations included the extreme habitats of the Alkaline Lakes in the western Nebraska Sandhills and the contaminated stream, Johnson Creek, bordering the AltEn 2021 catastrophic pesticide release near the village of Mead in eastern Nebraska. Maximum likelihood and genetic distance metrics supported the genetic integrity of the haplotype groups.

of the Prairie: A Case Study of Taxonomic Resolution from a Nematode Biodiversity Survey.

Taxonomic resolution is a critical component of biodiversity assessments. In this case study, we examined a single taxon within a larger study of nematode diversity to evaluate the taxonomic resolution of different diversity assessment methods. The selected taxon was the microbial-feeding genus , a group considered to include multiple cosmopolitan species.

Ecological and Morphological Differentiation Among COI Haplotype Groups in the Plant Parasitic Nematode Species .

DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, . Biological attributes of these haplotype groups (HG) have not been explored. An analysis of from 40 North American sites representing both native plant communities and agroecosystems was conducted to identify possible subgroup associations with ecological, physiological, or geographic factors.

, a new nematode species (Pratylenchidae: Tylenchomorpha) from the Great Plains region of North America.

is a new species of root-lesion nematode described from corn-soybean production fields in the Central Great Plains of North America. It is characterized by populations with relatively abundant males, two lip annuli, females with a round functional spermatheca and a conoid to subcylindrical tail with a non-crenate, smooth terminus. In host preference tests, corn and wheat produce the largest nematode populations, whereas sorghum and soybeans produce less than 20% the numbers observed on corn.

A global database of soil nematode abundance and functional group composition.

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition.

DNA barcoding evidence for the North American presence of alfalfa cyst nematode, .

Specimens of have been collected from alfalfa fields in Kearny County, Kansas & Carbon County, Montana. DNA barcoding with the COI mitochondrial gene indicate that the species is not , soybean cyst nematode, , sugar beet cyst nematode, or , clover cyst nematode. Maximum likelihood phylogenetic trees show that the alfalfa specimens form a sister clade most closely related to , with a 4.

Discovery and Identification of Species Using COI DNA Barcoding.

DNA barcoding with a new cytochrome oxidase c subunit 1 primer set generated a 721 to 724 bp fragment used for the identification of 322 Meloidogyne specimens, including 205 new sequences combined with 117 from GenBank. A maximum likelihood analysis grouped the specimens into 19 well-supported clades and four single-specimen lineages. The "major" tropical apomictic species ( Meloidogyne arenaria , Meloidogyne incognita , Meloidogyne javanica ) were not discriminated by this barcode although some closely related species such as Meloidogyne konaensis were characterized by fixed diagnostic nucleotides.

An 18S rDNA Perspective on the Classification of Criconematoidea.

In the nematode family Criconematidae, a taxonomy primarily based on cuticle characters has created classifications that are notoriously volatile. Molecular characters may lead to their stabilization. A phylogenetic tree of Criconematoidea was constructed using 166 new near full-length 18S rDNA sequences and 58 sequences from GenBank.

MOTUs, Morphology, and Biodiversity Estimation: A Case Study Using Nematodes of the Suborder Criconematina and a Conserved 18S DNA Barcode.

DNA barcodes are increasingly used to provide an estimate of biodiversity for small, cryptic organisms like nematodes. Nucleotide sequences generated by the barcoding process are often grouped, based on similarity, into molecular operational taxonomic units (MOTUs). In order to get a better understanding of the taxonomic resolution of a 3' 592-bp 18S rDNA barcode, we have analyzed 100 MOTUs generated from 214 specimens in the nematode suborder Criconematina.

Morphological and molecular characterization of Discocriconemella inarata, an endemic nematode from north american native tallgrass prairies.

Discocriconemella inarata, a plant parasitic nematode species originally discovered in a virgin tallgrass prairie in northwest Iowa, was re-examined by molecular and morphological analyses of topotype material. This species has never been recorded in cultivated fields and could potentially serve as an indicator for high quality prairie habitats. DNA sequence from a conserved 3' portion of the 18S ribosomal gene exhibited an identical match between D.