A New Era in Federal Quarantine and State Certification Diagnostics at Clean Plant Centers in the USA.

Quarantine and certification programs exist to prevent the entry or spread of harmful pests and pathogens into agricultural systems. Their common objective is to identify pathogen-free source material through the application of validated testing methods for subsequent release for propagation. Tests must be accurate, efficient and cost-effective.

Discovery and Characterization of Two Highly Divergent Variants of a Novel Species Infecting Madagascar Periwinkle ( ).

During the summer of 2022, a cluster of Madagascar periwinkle plants with white and mauve flowers were observed with foliar mild yellow mosaic symptoms on a private property in Harlingen, Cameron County, Texas. The symptoms were reproduced on mechanically inoculated periwinkle and plants. Virions of 776 to 849 nm in length and 11.

Molecular characterization of a divergent genetic variant of wheat Eqlid mosaic virus from a Texas wheat field.

Investigations conducted during the spring 2020 season to diagnose the associated viral agent of a severe mosaic disease of wheat in a Texas Panhandle field revealed the presence of wheat Eqlid mosaic virus (WEqMV; genus Tritimovirus, family Potyviridae) in the analyzed samples. The complete genome sequences of two WEqMV isolates were determined, and each was found to be 9,634 nucleotides (nt) in length (excluding the polyA tail) and to contain 5' and 3' untranslated regions of 135 nt and 169 nt, respectively, based on rapid amplification of cDNA ends (RACE) assays. Both sequences contained an open reading frame (ORF) of 9,330 nt encoding a polyprotein of 3,109 amino acids (aa).

First report of infecting crinium lily ( sp.) in Texas.

sp. (family ) is an ornamental flower bulb that is commonly called crinum lily, cape lily, cemetery plant, spider lily, and swamp lily. In April 2023, two plants of Crinum sp.

First report on the presence of huanglongbing vectors (Diaphorina citri and Trioza erytreae) in Ghana.

As significant threats to global citrus production, Diaphorina citri (Kuwayama; Hemiptera: Psyllidae) and Trioza erytreae (Del Guercio; Hemiptera: Triozidae) have caused considerable losses to citrus trees globally. Diaphorina citri vectors "Candidatus Liberibacter asiaticus" and "Ca. L.

Mitigation of Huanglongbing: Implications of a Biologically Enhanced Nutritional Program on Yield, Pathogen Localization, and Host Gene Expression Profiles.

Huanglongbing (HLB, citrus greening disease), the most destructive disease affecting citrus production, is primarily linked to the gram-negative, insect-vectored, phloem-inhabiting α-proteobacterium ' Liberibacter asiaticus' (CLas). With no effective treatment available, management strategies have largely focused on the use of insecticides in addition to the destruction of infected trees, which are environmentally hazardous and cost-prohibitive for growers, respectively. A major limitation to combating HLB is the inability to isolate CLas in axenic culture, which hinders studies and creates a need for robust CLas detection and visualization methods.

Report on the first detection of Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) in the Republic of Benin, West Africa.

The Asian citrus psyllid (ACP), Diaphorina citri, was detected for the first time in the Republic of Benin, West Africa. The ACP is a known vector of Candidatus Liberibacter asiaticus (CLas), the putative causal agent of the devastating Huanglongbing (HLB; citrus greening disease). During visual surveys, ACP was only observed on residential citrus trees in southern Benin, but not in residential areas or commercial groves in the central and northern parts of the country.

Survey for Virus Diversity in Common Bean () Fields and the Detection of a Novel Strain of in Zambia.

The production of common bean ( L.) is adversely affected by virus-like diseases globally, but little is known about the occurrence, distribution, and diversity of common bean-infecting viruses in Zambia. Consequently, field surveys were conducted during the 2018 season in 128 fields across six provinces of Zambia and 640 common bean leaf tissue samples were collected with ( = 585) or without ( = 55) symptoms.

Cotton Leafroll Dwarf Virus US Genomes Comprise Divergent Subpopulations and Harbor Extensive Variability.

Cotton leafroll dwarf virus (CLRDV) was first reported in the United States (US) in 2017 from cotton plants in Alabama (AL) and has become widespread in cotton-growing states of the southern US. To investigate the genomic variability among CLRDV isolates in the US, complete genomes of the virus were obtained from infected cotton plants displaying mild to severe symptoms from AL, Florida, and Texas. Eight CLRDV genomes were determined, ranging in size from 5865 to 5867 bp, and shared highest nucleotide identity with other CLRDV isolates in the US, at 95.

Identification of a Chromosomal Deletion Mutation and the Dynamics of Two Major Populations of ' Liberibacter asiaticus' in Its Hosts.

' Liberibacter asiaticus' (Las) is the prominent species of associated with huanglongbing, a devastating disease of citrus worldwide. In this study, we report the identification of an ∼8.3-kb DNA region of the Las genome containing eight putative open reading frames flanked by two inverted repeats, which was not present in the Las str.

Olea europaea geminivirus is present in a germplasm repository and in California and Texas olive (Olea europaea L.) groves.

Olea europaea geminivirus (OEGV) from olive accessions in Italy was characterized recently. OEGV was also detected during routine high-throughput sequencing screening of olive (cv. Leccino) material, and its complete bipartite genome segments were sequenced and shown to be 100% identical to those of the isolate from Italy.

First report of squash vein yellowing virus naturally infecting butternut squash () in Texas.

Virus diseases are major constraints to the production of cucurbits in the Texas Lower Rio Grande Valley. In September 2020, a ~8.1 ha butternut squash () field in Hidalgo County, Texas, was observed with virus-like symptoms of vein yellowing, leaf curl, mosaic, and foliar chlorosis.

First report of infecting cantaloupe ( L.) in Texas.

Texas is a major producer of cucurbits such as cantaloupe ( L.), but outbreaks of virus-like diseases often adversely affect yields. Little is known about the identity of the causal or associated viruses.

First report of watermelon crinkle leaf-associated virus 1 (WCLaV-1) and WCLaV-2 infecting watermelon () in the United States.

Watermelon () and other cucurbits are cultivated globally, and Texas ranks among its top 5 producers in the U.S. In July 2020, plants with virus-like disease symptoms consisting of mild leaf crinkling and yellow mosaic patterns were observed in a 174-ha watermelon field in Burleson Co.

Characterization of a New Nepovirus Infecting Grapevine.

In 2012, dormant canes of a proprietary wine grape ( L.) accession were included in the collection of the University of California-Davis Foundation Plant Services. No virus-like symptoms were elicited when bud chips from propagated own-rooted canes of the accession were graft-inoculated onto a panel of biological indicators.

First report of Ethiopian tobacco bushy top virus and its associated satellite RNA infecting common bean (Phaseolus vulgaris L.) in Zambia.

During surveys for common bean viruses in Central Province of Zambia in April 2018, symptoms of bushy top, deep green curled branches and patchy leaf chlorosis were observed on five plants in a 2-ha farmer's field. Total RNA was isolated from symptomatic leaf samples using the CTAB method (Chang et al. 1993).

Correction To: Detection and diversity of maize yellow mosaic virus infecting maize in Nigeria.

[This corrects the article DOI: 10.1007/s13337-019-00555-0.].

Incidence, Severity, and Characterization of Phytophthora Foot Rot of Citrus in Texas and Implications for Disease Management.

-induced foot rot, also known as gummosis, is an important disease affecting citrus production worldwide. In Texas, the third-largest citrus-producing state in the United States, limited information is available on the etiology and epidemiology of foot rot in commercial orchards. This study comprises a survey of foot rot incidence and severity in Texas and the characterization of isolates associated with the disease.

First report of the occurrence of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae), an invasive species in Nigeria, West Africa.

The Asian citrus psyllid (ACP; Diaphorina citri) is the vector of Candidatus Liberibacter asiaticus (CLas) that is associated with the devastating Huanglongbing (HLB; citrus greening disease). This pest of Asian origin has spread into the Americas and more recently into a few countries in East Africa. During recent surveys, suspect ACP adults and nymphs were recorded for the first time infesting citrus trees in southwest Nigeria.

Complete genome sequence analysis of a genetic variant of grapevine virus L from the grapevine cultivar Blanc du Bois.

The complete genome sequences of two grapevine virus L (GVL) isolates collected from the wine grape cultivar Blanc du Bois (Vitis spp.: 'Florida D 6-148'×'Cardinal') in Texas were determined. The two genome sequences (excluding the polyA tail) were each 7594 nucleotide long and 99.

Distribution of Liberibacter asiaticus in Citrus and the Asian Citrus Psyllid in Texas Over a Decade.

Huanglongbing (HLB, citrus greening disease) in the major citrus-producing states of the United States is associated with Liberibacter asiaticus (CLas), which is vectored by the Asian citrus psyllid (ACP). Surveys were conducted in Texas from 2007 to 2017 to assess the prevalence and titer of CLas in ACPs and citrus trees. ACP and citrus leaf tissue samples were collected from suspect trees in residential areas and commercial groves (orchards) and assayed for CLas by quantitative PCR.