Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication Year
- Publication
- Publication Type
Articles 1 - 19 of 19
Full-Text Articles in Life Sciences
The Plants Database: Providing Basic Plant Information, J S. Peterson, J F. Henson, W Oaks, J T. Kartesz
The Plants Database: Providing Basic Plant Information, J S. Peterson, J F. Henson, W Oaks, J T. Kartesz
IGC Proceedings (1997-2023)
The PLANTS database provides basic plant information to the United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), its clients, cooperators, and the general public via the World Wide Web (Fig. 1). The foundation of PLANTS is a taxonomic backbone (checklist) of the vascular and nonvascular plants of North America (north of Mexico) and United States territories in the Caribbean and Pacific regions. Attribute data are appended to this backbone pertaining to distribution, vegetative specifications, nativity, federal and state status, crop data, growth form, growth parameters, species abstracts, and images.
Plectus Of The Prairie: A Case Study Of Taxonomic Resolution From A Nematode Biodiversity Survey, Abigail Borgmeier, Kaitlin Gattoni, Timothy Harris, Rebecca Higgins, Peter Mullin, Dorota Porazinska, Kirsten S. Powers, David A. Wedin, Tom Powers
Plectus Of The Prairie: A Case Study Of Taxonomic Resolution From A Nematode Biodiversity Survey, Abigail Borgmeier, Kaitlin Gattoni, Timothy Harris, Rebecca Higgins, Peter Mullin, Dorota Porazinska, Kirsten S. Powers, David A. Wedin, Tom Powers
Department of Plant Pathology: Faculty Publications
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 Plectus, a group considered to include multiple cosmopolitan species. The methods included a morphological evaluation by light microscopy, Sanger sequencing of PCR amplicons of COI and 18S gene regions, and 18S metabarcoding sequencing. The study sites were 15 remnant tallgrass prairie plots in eastern Nebraska. In the morphological analysis, we observed two basic morphotypes, a short-tailed form …
Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Thomas O. Powers
Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, Mesocriconema xenoplax. Biological attributes of these haplotype groups (HG) have not been explored. An analysis of M. xenoplax 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 dataset of 132 M. xenoplax specimens was used to generate sequences of a 712 bp region of the cytochrome oxidase subunit I gene. Maximum-likelihood and Bayesian phylogenies recognized seven COI HG (≥99/0.99 posterior probability/bootstrap value). Species delimitation …
Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Tom Powers
Ecological And Morphological Differentiation Among Coi Haplotype Groups In The Plant Parasitic Nematode Species Mesocriconema Xenoplax, Julianne N. Matczyszyn, Timothy Harris, Kirsten S. Powers, Sydney E. Everhart, Tom Powers
Department of Plant Pathology: Faculty Publications
DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, Mesocriconema xenoplax. Biological attributes of these haplotype groups (HG) have not been explored. An analysis of M. xenoplax 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 dataset of 132 M. xenoplax specimens was used to generate sequences of a 712 bp region of the cytochrome oxidase subunit I gene. Maximum-likelihood and Bayesian phylogenies recognized seven COI HG (≥99/0.99 posterior probability/bootstrap value). Species …
Nematode Biodiversity In Lincoln, Nebraska's Tallgrass Prairie Corridor, Abigail Borgmeier
Nematode Biodiversity In Lincoln, Nebraska's Tallgrass Prairie Corridor, Abigail Borgmeier
Department of Plant Pathology: Dissertations, Theses, and Student Research
The tallgrass prairie was once one of the most diverse grasslands on the planet, however over 95% has been converted to agriculture in the past 150 years. The remaining prairie is still host to a wide variety of plants, insects, mammals, and soil-dwelling microorganisms, creating an incredibly complex ecosystem. The first aim of this study is to compare three approaches for the measurement of nematode diversity within a 10-mile-long protected prairie habitat corridor near Lincoln, Nebraska. The methods are 1) a traditional morphological analysis of 150 nematodes per study site, 2) a metabarcoding analysis using the 18S genetic marker of …
Dna Barcoding Evidence For The North American Presence Of Alfalfa Cyst Nematode, Heterodera Medicaginis, Tom Powers, Andrea Skantar, Timothy Harris, Rebecca Higgins, Peter Mullin, Saad Hafez, Zafar Handoo, Tim Todd, Kirsten S. Powers
Dna Barcoding Evidence For The North American Presence Of Alfalfa Cyst Nematode, Heterodera Medicaginis, Tom Powers, Andrea Skantar, Timothy Harris, Rebecca Higgins, Peter Mullin, Saad Hafez, Zafar Handoo, Tim Todd, Kirsten S. Powers
Department of Plant Pathology: Faculty Publications
Specimens of Heterodera have been collected from alfalfa fields in Kearny County, Kansas and Carbon County, Montana. DNA barcoding with the COI mitochondrial gene indicate that the species is not Heterodera glycines, soybean cyst nematode, H. schachtii, sugar beet cyst nematode, or H. trifolii, clover cyst nematode. Maximum likelihood phylogenetic trees show that the alfalfa specimens form a sister clade most closely related to H. glycines, with a 4.7% mean pairwise sequence divergence across the 862 nucleotides of the COI marker. Morphological analyses of juveniles and cysts conform to the measurements of H. medicaginis, the alfalfa cyst nematode originally described …
The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis
The Family Rhabdoviridae: Mono- And Bipartite Negative-Sense Rna Viruses With Diverse Genome Organization And Common Evolutionary Origins, Ralf G. Dietzgen, Hideki Kondo, Michael M. Goodin, Gael Kurath, Nikos Vasilakis
Plant Pathology Faculty Publications
The family Rhabdoviridae consists of mostly enveloped, bullet-shaped or bacilliform viruses with a negative-sense, single-stranded RNA genome that infect vertebrates, invertebrates or plants. This ecological diversity is reflected by the diversity and complexity of their genomes. Five canonical structural protein genes are conserved in all rhabdoviruses, but may be overprinted, overlapped or interspersed with several novel and diverse accessory genes. This review gives an overview of the characteristics and diversity of rhabdoviruses, their taxonomic classification, replication mechanism, properties of classical rhabdoviruses such as rabies virus and rhabdoviruses with complex genomes, rhabdoviruses infecting aquatic species, and plant rhabdoviruses with both mono- …
Species Delimitation And Description Of Mesocriconema Nebraskense N. Sp. (Nematoda: Criconematidae), A Morphologically Cryptic, Parthenogenetic Species From North American Grasslands, Magdalena Olson, Timothy Harris, Rebecca Higgins, Peter Mullin, Kirsten Powers, Sean Olson, Thomas O. Powers
Species Delimitation And Description Of Mesocriconema Nebraskense N. Sp. (Nematoda: Criconematidae), A Morphologically Cryptic, Parthenogenetic Species From North American Grasslands, Magdalena Olson, Timothy Harris, Rebecca Higgins, Peter Mullin, Kirsten Powers, Sean Olson, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
Nematode surveys of North American grasslands conducted from 2010 to 2015 frequently recovered a species of criconematid nematode morphologically resembling Mesocriconema curvatum. These specimens were recovered from remnant native prairies in the central tallgrass ecoregion of North America, and not from surrounding agroecosystems. Historical records indicate that M. curvatum is a cosmopolitan species feeding on a wide range of agronomic and native plants. DNA barcoding indicates North American grasslands contain at least 10 phylogenetically distinct lineages of Mesocriconema that resemble, but are not, M. curvatum. Analysis of the two most common lineages reveals two distinctly different population structures. …
Description Of Mesocriconema Ericaceum N. Sp. (Nematoda: Criconematidae) And Notes On Other Nematode Species Discovered In An Ericaceous Heath Bald Community In Great Smoky Mountains National Park, Usa, Thomas O. Powers, Peter Mullin, Rebecca Higgins, Timothy Harris, Kirsten S. Powers
Description Of Mesocriconema Ericaceum N. Sp. (Nematoda: Criconematidae) And Notes On Other Nematode Species Discovered In An Ericaceous Heath Bald Community In Great Smoky Mountains National Park, Usa, Thomas O. Powers, Peter Mullin, Rebecca Higgins, Timothy Harris, Kirsten S. Powers
Department of Plant Pathology: Faculty Publications
A new species of Mesocriconema and a unique assemblage of plant-parasitic nematodes was discovered in a heath bald atop Brushy Mountain in Great Smoky Mountains National Park. Mesocriconema ericaceum n. sp., a species with males, superficially resembles M. xenoplax. DNA barcoding with the mitochondrial COI gene provided evidence of the new species as a distinct lineage. SEM revealed significant variability in arrangement of labial submedian lobes, plates, and anterior and posterior annuli. Three other nematodes in the family Criconematidae were characterized from the heath bald. Ogma seymouri, when analyzed by statistical parsimony, established connections with isolates from north-eastern Atlantic …
Morphological And Molecular Characterization Of Gracilacus Wuae N. Sp. (Nematoda: Criconematoidea) Associated With Cow Parsnip (Heracleum Maximum) In Ontario, Canada, Qing Yu, Weimin Ye, Thomas O. Powers
Morphological And Molecular Characterization Of Gracilacus Wuae N. Sp. (Nematoda: Criconematoidea) Associated With Cow Parsnip (Heracleum Maximum) In Ontario, Canada, Qing Yu, Weimin Ye, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 mmlong, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of …
Recommendations Of Generic Names In Diaporthales Competing For Protection Or Use, Amy Y. Rossman, Gerard C. Adams, Paul F. Cannon, Lisa A. Castlebury, Pedro W. Crous, Marieka Gryzenhout, Walter M. Jaklitsch, Luis C. Mejia, Dmitar Stoykov, Dhanushka Udayanga, Hermann Voglmayr, Donald M. Walker
Recommendations Of Generic Names In Diaporthales Competing For Protection Or Use, Amy Y. Rossman, Gerard C. Adams, Paul F. Cannon, Lisa A. Castlebury, Pedro W. Crous, Marieka Gryzenhout, Walter M. Jaklitsch, Luis C. Mejia, Dmitar Stoykov, Dhanushka Udayanga, Hermann Voglmayr, Donald M. Walker
Department of Plant Pathology: Faculty Publications
In advancing to one name for fungi, this paper treats generic names competing for use in the order Diaporthales (Ascomycota, Sordariomycetes) and makes a recommendation for the use or protection of one generic name among synonymous names that may be either sexually or asexually typified. A table is presented that summarizes these recommendations. Among the genera most commonly encountered in this order, Cytospora is recommended over Valsa and Diaporthe over Phomopsis. New combinations are introduced for the oldest epithet of important species in the recommended genus. These include Amphiporthe tiliae, Coryneum lanciforme, Cytospora brevispora, C. ceratosperma, C. …
Ficotylus Laselvae N. Sp. (Tylenchomorpha: Anguinidae) Associated With Ficus Colubrinae In Costa Rica, Robin M. Giblin-Davis, Natsumi Kanzaki, Kerrie A. Davies, Weimin Ye, Yongsan Zeng, Barbara J. Center, Alejandro Esquivel, Thomas O. Powers
Ficotylus Laselvae N. Sp. (Tylenchomorpha: Anguinidae) Associated With Ficus Colubrinae In Costa Rica, Robin M. Giblin-Davis, Natsumi Kanzaki, Kerrie A. Davies, Weimin Ye, Yongsan Zeng, Barbara J. Center, Alejandro Esquivel, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
Ficotylus laselvae n. sp. was recovered from under the bracts of figs (syconia) of Ficus colubrinae from La Selva, Costa Rica, during a survey of nematode rainforest biodiversity and is described herein. This is only the second report of an association between the nematode suborder Tylenchina and the sycones of figs. Previous reports of most nematode associates of the sycones of figs have been from the lumen and involved transmission by female fig wasp pollinators (Agaonidae) during pollination/oviposition (e.g., Schistonchus and Parasitodiplogaster spp.). The association between F. laselvae n. sp. and Ficus colubrinae may involve an invertebrate host, …
Morphological And Molecular Taxonomic Identification And Phylogenetics Of Criconematoidea, Marco Cordero
Morphological And Molecular Taxonomic Identification And Phylogenetics Of Criconematoidea, Marco Cordero
Graduate Theses and Dissertations
The superfamily Criconematoidea has been studied since 1886. It is composed of two families: Criconematidae (subfam. Criconematinae, Hemicycliophorinae) and Tylenchulidae (subfam. Tylenchulinae, Paratylenchinae and Tylenchocriconematinae). Multiple species in genera have been identified and differences and similarities have been found. Species belonging to genera Mesocriconema and Criconemoides show very few differences making their identification difficult. Seventy two populations were studied. They were collected in Arkansas and/or received from the following states: California, Florida, Kansas, Missouri, North Carolina and Tennessee. Populations of the following species were identified: Mesocriconema curvatum, M. kirjanovae, M. onoense, M. ornatum, M. sphaerocephala, M. surinamense, M. vadense, M. …
Phenotypic, Pathogenic, Molecular And Phylogenetic Comparisons Of Bacteria Causing Aloe Rot From Three Countries, Yogeshwar Kumar, Jatindra Nath Samanta, Kunal Mandal, Narendra A. Gajbhiye
Phenotypic, Pathogenic, Molecular And Phylogenetic Comparisons Of Bacteria Causing Aloe Rot From Three Countries, Yogeshwar Kumar, Jatindra Nath Samanta, Kunal Mandal, Narendra A. Gajbhiye
Kunal Mandal
Bacterial soft rot disease of Aloe caused by heterogeneous genus Erwinia was reported from different parts of the world. In the recent past the genus underwent major taxonomic modifications. In the present study, four Aloe pathogenic bacterial strains isolated from India, The Netherlands and Yugoslavia have been compared. Different cultural, biochemical, physiological and pathological characters and protein/lipid profiles indicated that the strains belonged to two different genera, Pectobacterium and Dickeya. Species specific amplification of pel gene sequences also supported this. Phylogenetic analysis of rRNA gene (rDNA) sequence placed these Dickeya strains close to D. dieffenbachiae and D. zeae. On the …
Vittatidera Zeaphila (Nematoda: Heteroderidae), A New Genus And Species Of Cyst Nematode Parasitic On Corn (Zea Mays), Ernest C. Bernard, Zafar A. Handoo, Thomas O. Powers, Patricia A. Donald, Robert D. Heinz
Vittatidera Zeaphila (Nematoda: Heteroderidae), A New Genus And Species Of Cyst Nematode Parasitic On Corn (Zea Mays), Ernest C. Bernard, Zafar A. Handoo, Thomas O. Powers, Patricia A. Donald, Robert D. Heinz
Department of Plant Pathology: Faculty Publications
A new genus and species of cyst nematode, Vittatidera zeaphila, is described from Tennessee. The new genus is superficially similar to Cactodera but is distinguished from other cyst-forming taxa in having a persistent lateral field in females and cysts, persistent vulval lips covering a circumfenestrate vulva, and subventral gland nuclei of the female contained in a separate small lobe. Infective juveniles (J2) are distinguished from all previously described Cactodera spp. by the short stylet in the second-stage juvenile (14-17 mm); J2 of Cactodera spp. have stylets at least 18 mm long. The new species also is unusual in that …
Free-Living Dorylaimid Nematodes From Nature Reserves In Costa Rica. The Genus Pachydorylaimus Siddiqi, 1983, A. Esquivel, P. Guerrero, R. Peña-Santiago, Thomas O. Powers
Free-Living Dorylaimid Nematodes From Nature Reserves In Costa Rica. The Genus Pachydorylaimus Siddiqi, 1983, A. Esquivel, P. Guerrero, R. Peña-Santiago, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
A taxonomic study of three species, two known and one new, belonging to the genus Pachydorylaimus Siddiqi, 1983 from natural areas in Costa Rica is presented. Pachydorylaimus holovachovi sp. n. is described and can be distinguished by its body 0.90-1.00 mm long, lip region 14-17 μm wide, odontostyle 13-15 μm long, odontophore morphology with differentiated hyaline spindle-shaped area surrounding its junction to pharyngeal lining but lacking distinct basal flanges, total stylet length 35- 44 μm, pars refringens vaginae absent, V = 43-47, female tail straight and tapering to an acute tip (57- 78 μm, c = 12.5-15.8, c’ = 2.0-3.0), …
Morphological And Molecular Characterization Of Meloidogyne Mayaguensis Isolates From Florida, J. Brito, Thomas O. Powers, P. G. Mullin, Florida Department Of Agriculture And Consumer Services N., D. W. Dickson
Morphological And Molecular Characterization Of Meloidogyne Mayaguensis Isolates From Florida, J. Brito, Thomas O. Powers, P. G. Mullin, Florida Department Of Agriculture And Consumer Services N., D. W. Dickson
Department of Plant Pathology: Faculty Publications
The discovery of Meloidogyne mayaguensis is confirmed in Florida; this is the first report for the continental United States. Meloidogyne mayaguensis is a virulent species that can reproduce on host cultivars bred for nematode resistance. The perineal patterns of M. mayaguensis isolates from Florida show morphological variability and often are similar to M. incognita. Useful morphological characters for the separation of M. mayaguensis from M. incognita from Florida are the male stylet length values (smaller for M. mayaguensis than M. incognita) and J2 tail length values (greater for M. mayaguensis than M. incognita). Meloidogyne mayaguensis values for …
The Rdna Internal Transcribed Spacer Region As A Taxonomic Marker For Nematodes, Thomas O. Powers, T. C. Todd, A. M. Burnell, P. C. B. Murray, C. C. Flemming, Allen L. Szalanski, B. A. Adams, T. S. Harris
The Rdna Internal Transcribed Spacer Region As A Taxonomic Marker For Nematodes, Thomas O. Powers, T. C. Todd, A. M. Burnell, P. C. B. Murray, C. C. Flemming, Allen L. Szalanski, B. A. Adams, T. S. Harris
Department of Plant Pathology: Faculty Publications
The ITS region from a wide taxonomic range of nematodes, including secernentean and adenophorean taxa, and free-living, entomopathogenic, and plant-parasitic species, was evaluated as a taxonomic marker. Size of the amplified product aided in the initial determination of group membership, and also suggested groups that may require taxonomic reevaluation. Congeneric species often displayed identically sized ITS regions, but genera such as Pratylenchus and Tylenchorhynchus had species with large differences in size. ITS heterogeneity in individuals and populations was identified in several nematode taxa. PCR-RFLP of ITS1 is advocated as a method of taxonomic analysis in genera such as Helicotylenchus that …
The Internal Transcribed Spacer Region Of Belonolaimus (Nemata: Belonolaimidae), T. Cherry, A. L. Szalanski, T. C. Todd, Thomas O. Powers
The Internal Transcribed Spacer Region Of Belonolaimus (Nemata: Belonolaimidae), T. Cherry, A. L. Szalanski, T. C. Todd, Thomas O. Powers
Department of Plant Pathology: Faculty Publications
Belonolaimus isolates from six U.S. states were compared by restriction endonuclease digestion of amplified first internal transcribed spacer region (ITS1) of the nuclear ribosomal genes. Seven restriction enzymes were selected for evaluation based on restriction sites inferred from the nucleotide sequence of a South Carolina Belonolaimus isolate. Amplified product size from individuals of each isolate was approximately 700 bp. All Midwestern isolates gave distinct restriction digestion patterns. Isolates identified morphologically as Belonolaimus longicaudatus from Florida, South Carolina, and Palm Springs, California, were identical for ITS1 restriction patterns. The correlation between ITS1 restriction patterns and the distribution of B. longicaudatus isolates …