Plant Pathogen Name Game: Cross Kingdom Review for the Naming of Biotic Agents Associated with Plants.

To communicate across scientific disciplines, regulatory bodies, and the agricultural community, the naming of plant pathogens assigned to specific taxa is critical. Here, we provide an overview of the nomenclatural systems governing the naming of plant-pathogenic nematodes, fungi, oomycetes, prokaryotes, and viruses. Although we focus on the nature of the nomenclatural codes, we briefly discuss fundamental principles of taxonomy, including classification and identification.

Characterization of Tobacco ringspot virus and its nematode vector, , infecting Highbush Blueberry in Washington State.

Highbush blueberry (Vaccinium corymbosum L.) plants showing stunting and severe defoliation were observed in an organic blueberry farm in eastern Washington State. Initially, leaves of affected blueberry plants showed crinkling and mottling, chlorotic spots and red-colored rings with chlorotic centers.

Tiny Invaders, Big Trouble: Emerging Nematode Threats in the United States.

Plant-parasitic nematodes (PPNs) cause billions of dollars in agricultural losses annually. In the United States, a well-established list of prevalent nematodes serves as a foundation for addressing known threats. However, climate change is expected to trigger significant shifts in nematode populations, behaviors, and host ranges, introducing new risks to agricultural ecosystems.

Deciphering the vectors: Unveiling the local dispersal of Litylenchus crenatae ssp. mccannii in the American beech (Fagus grandifolia) forest ecosystem.

Beech leaf disease (BLD), caused by the Litylenchus crenatae ssp. mccannii (Lcm) nematode, is an emerging threat to beech trees. This disease is characterized by distinct leaf symptoms, including leaf interveinal banding and thickened leaf texture, which leads to eventual tree mortality.

Understanding the dynamic interactions of root-knot nematodes and their host: role of plant growth promoting bacteria and abiotic factors.

Root-knot nematodes ( spp., RKN) are among the most destructive endoparasitic nematodes worldwide, often leading to a reduction of crop growth and yield. Insights into the dynamics of host-RKN interactions, especially in varied biotic and abiotic environments, could be pivotal in devising novel RKN mitigation measures.

Biosecurity risks to human food supply associated with plant-parasitic nematodes.

Biosecurity in agriculture is essential for preventing the introduction and spread of plant-parasitic nematodes (PPNs) which threaten global food security by reducing crop yields and facilitating disease spread. These risks are exacerbated by increased global trade and climate change, which may alter PPN distribution and activity, increasing their impact on agricultural systems. Addressing these challenges is vital to maintaining the integrity of the food supply chain.

First report of barley root-knot nematode, from turfgrass in Idaho, with multigene molecular characterization.

Barley root-knot nematode, Franklin, 1965, is one of the most important pest nematodes infecting monocots (Franklin, 1965). Two-inch core soil samples collected from a golf course in Ada County, Idaho were submitted for identification in November of 2019. A high number of sp.

Cellular insights of beech leaf disease reveal abnormal ectopic cell division of symptomatic interveinal leaf areas.

The beech leaf disease nematode, Litylenchus crenatae subsp. mccannii, is recognized as a newly emergent nematode species that causes beech leaf disease (BLD) in beech trees (Fagus spp.) in North America.

Morphological Characterization of Fresh and 20-Yr-Old Fixed Nematode Specimens of (Allen, 1955) Siddiqi, 2000 Deposited in the USDA Nematode Collection from Arlington National Cemetery, VA, USA.

was discovered during a survey conducted at the Arlington National Cemetery, Virginia, for the type specimens of . Besides the fresh material, the fixed specimens of were also studied by molecular and morphological means. The morphological and morphometric characteristics of the recovered fresh material were consistent with the original and other description(s) of this species.

Morphological and Molecular Characterization of Brzeski, 1998 (Nematoda: Heteroderidae) from Virginia, USA.

In August of 2021, several cysts with juveniles and eggs were discovered during a vegetation survey conducted at the Arlington National Cemetery, Virginia. Eight soil samples were collected from the rhizosphere region of the common grass () and processed at the Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL). Cysts were light to dark brown in color, and oval to pear-shaped without bullae in young cysts but present in older cysts and with prominent vulval cone.

First report of Seville root-knot nematode, (Nematoda: Meloidogynidae) in the USA and North America.

A high number of second stage juveniles of the root-knot nematode were recovered from soil samples collected from a corn field, located in Pickens County, South Carolina, USA in 2019. Extracted nematodes were examined morphologically and molecularly for species identification which indicated that the specimens of root knot juveniles were The morphological examination and morphometric details from second-stage juveniles were consistent with the original description and redescriptions of this species. The ITS rRNA, D2-D3 expansion segments of 28S rRNA, intergenic -16S region, and gene sequences were obtained from the South Carolina population of .

Molecular and morphological characterization of a first report of Cid del Prado Vera & Subbotin, 2014 (Nematoda: Heteroderidae) from Minnesota, the United States of America.

Cid del Prado Vera & Subbotin, 2014 cysts were discovered during a Pale Potato Cyst Nematode (PCN) survey conducted by Minnesota Department of Agriculture as part of the Animal and Plant Health Inspection Service (APHIS) efforts to survey states for the presence of PCN. The soil samples were collected from a potato field, located in Karlstad, Kittson County, Minnesota, USA. Two out of 175 vials submitted for identification to the Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL) contained few cysts and juveniles of .

Morphological and molecular characterization of n. sp. (Tylenchida: Paratylenchidae) from the rhizosphere of pine tree ( Mill) in Maryland, USA.

The pin nematode, n. sp. collected from rhizosphere soil of a Virginia pine tree ( Mill) growing in Little Paint Branch Park, Beltsville, Prince George's County, Maryland, USA, is described and illustrated along with light and scanning electron photomicrographs.

First report of Graney and Bird, 1990 from Colorado and Minnesota.

In 2019, cysts were discovered from soil samples collected from a field, located in Mosca, Alamosa county, Colorado, USA. Approximately 200 lemon shaped cysts and several hundred juveniles were recovered from the affected quinoa plants. The same species was also identified from several counties in Minnesota from samples submitted over the years by the Minnesota Department of Agriculture as part of the Animal and Plant Health Inspection Service (APHIS) efforts to survey states for the presence of Pale Potato Cyst Nematode.

On the molecular identity of (Nematoda: Tylenchida).

In this study, molecular characterization of collected from the type locality in Four Mile Run, Fall Church, Virginia using D2-D3 of 28 S rRNA and ITS rRNA gene sequences was provided. We molecularly also characterized, specimens collected from grasses in Devils Lake, Ramsey County, North Dakota indicated as the type locality in the original description of by Cobb (1923). These nematodes were identified as representatives of the species Populations of belonging to the molecular types A and B, and previously designated by Van den Berg et al.

Taxonomy and Identification of Principal Foliar Nematode Species ( and ).

Nematodes are Earth's most numerous multicellular animals and include species that feed on bacteria, fungi, plants, insects, and animals. Foliar nematodes are mostly pathogens of ornamental crops in greenhouses, nurseries, forest trees, and field crops. Nematode identification has traditionally relied on morphological and anatomical characters using light microscopy and, in some cases, scanning electron microscopy (SEM).

Chia: Host Status for and Activity of Plant Extracts.

Chia ( L.) seeds are used for food, drinks, oil, and animal feed, and all plant parts are employed in traditional medicine. The growing demand for the seed has created a need for improved disease management.

and fungal endophyte associations: host status for and nematotoxic plant extracts.

hybrids are forage grasses used worldwide in temperate climates. They are associated with the fungal endophyte , which aids in nutrient uptake, drought tolerance, and production of metabolites that protect against parasites and herbivores. produces loline alkaloids, which can deter insect pests.

Molecular and morphological characterization of the amaryllis lesion nematode, (Inserra et al., 2007), from California.

Root-lesion nematodes ( spp.) are among the most important nematode pests on grapevine along with root-knot, dagger, and ring nematodes. In 2019, two samples of both soil and roots were collected from a vineyard in Delano, Kern County, California and submitted to the United States Department of Agriculture, ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory, Beltsville, MD, for identification purposes.

Characterization of (Nematoda: Heteroderidae) from Indiana with molecular phylogenetic analysis of the genus.

In the summer of 2016, a field of corn () in Spencer County, Indiana was observed with heavily stunted plants, and from the affected roots a large number of cysts were recovered. Soil samples were submitted to one of us (JF), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and the recovered second-stage juveniles (J2) that were examined morphologically conformed to the measurements of , the goose cyst nematode originally described from Tennessee, USA in 2010.

Molecular and morphological characterization of the alfalfa cyst nematode, , from Utah.

In the spring of 2019, a cyst nematode was discovered from soil samples collected from an alfalfa field in Millard County, Utah. The soil samples were submitted to one of us (SH), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and living nematode juveniles (J2) recovered from the cysts were examined morphologically and molecularly for species identification which indicated that the specimens were This represents the first record of in Utah and the second report of this nematode in North America.

First report of the cactus cyst nematode, from a cactus garden in Idaho.

In April 2018, a cyst nematode was discovered from soil samples collected from a cactus garden collection in Meridian, Ada County, Idaho, USA. The cactus garden collection field reported was observed with localized areas of heavily stunted plants. Roots from affected plants displayed moderate numbers of nematode cysts.

NMR Analysis Reveals a Wealth of Metabolites in Root-Knot Nematode Resistant Roots of Watermelon Plants.

Citrullus amarus ( CA ) (previously known as Citrullus lanatus var. citroides ) accessions collected in southern Africa are known to have resistance to root-knot nematodes (RKN) and are suitable rootstocks for grafted watermelon. The objective of this study was to conduct a comparative metabolomics analysis and identify unique metabolites in roots of CA accessions versus roots of watermelon cultivars ( Citrullus lanatus (Thunb.