A high-throughput plate method for nucleic acid extraction from beet leafhopper (Hemiptera: Cicadellidae) and potato psyllid (Hemiptera: Triozidae) for pathogen detection.

Plant pathogens that are transmitted by insect vectors cause considerable damage to crops when pests or pathogens are not detected early in the season and populations are not controlled. Knowledge of pathogen prevalence in insect pest populations can aid growers in their insect pest management decisions but requires the timely dissemination of results. This process requires that specimen capture, identification, nucleic acid extraction, and molecular detection of a pathogen(s) occur alongside a platform for sharing results.

A robust SNP-haplotype assay for gene region conferring resistance to in common bean ( L.).

Beet curly top virus (BCTV), which is synonymous with curly top virus (CTV), causes significant yield loss in common bean (snap and dry beans) cultivars and several other important crops. Common bean cultivars have been found to be resistant to CTV, but screening for resistance is challenging due to the cyclical nature of epidemics and spotty feeding by the leafhopper that vectors the virus. We used an SNP dataset for the Snap Bean Association Panel (SnAP) agro-inoculated with CTV-Logan (CA/Logan) strain to locate the gene region to a 1.

New Assays for Rapid Detection of Beet Leafhopper-Associated Plant Pathogens, ' Phytoplasma trifolii', Beet Curly Top Virus, and .

The beet leafhopper is an important pest of agricultural crops in the United States, where it transmits beet curly top virus, beet leafhopper-transmitted virescence agent phytoplasma, and to numerous crops, affecting yield and quality. Each of these pathogens have been linked to serious disease outbreaks within Washington State in the past century. To mitigate the risk of disease, growers target the beet leafhopper in their insect pest management programs.

Bacterial Endosymbionts Identified From Leafhopper (Hemiptera: Cicadellidae) Vectors of Phytoplasmas.

Insects often harbor bacterial endosymbionts that provide them with nutritional benefit or with protection against natural enemies, plant defenses, insecticides, and abiotic stresses. Certain endosymbionts may also alter acquisition and transmission of plant pathogens by insect vectors. We identified bacterial endosymbionts from four leafhopper vectors (Hemiptera: Cicadellidae) of 'Candidatus Phytoplasma' species by direct sequencing 16S rDNA and confirmed endosymbiont presence and identity by species-specific conventional PCR.

Acquisition and Transmission of ' Liberibacter solanacearum' Differs Among -Infected and -Uninfected Haplotypes of .

' Liberibacter solanacearum' (Lso) causes disease symptoms and economic losses in potato, tomato, and other solanaceous crops in North America. Lso is transmitted to plants by the potato psyllid, , which occurs as distinct haplotypes named western, central, and northwestern that differ in the presence or absence of the bacterial endosymbiont, . Previous work showed that all three vector haplotypes can transmit Lso, but it was not clear whether acquisition and transmission rates of Lso were equal among the haplotypes.

Development of a Loop-Mediated Isothermal Amplification (LAMP) Method to Detect the Potato Zebra Chip Pathogen ' Liberibacter solanacearum' (Lso) and Differentiate Haplotypes A and B.

' Liberibacter solanacearum' (Lso) is the causal agent of zebra chip of potato (), which can significantly reduce potato yield. In this study, a loop-mediated isothermal amplification (LAMP) method for the detection of Lso haplotypes A and B was developed and evaluated. Two sets of LAMP primers named LAMP-A and LAMP-B were designed and tested for specificity and sensitivity.

Bacterial Endosymbionts of Bactericera maculipennis and Three Mitochondrial Haplotypes of B. cockerelli (Hemiptera: Psylloidea: Triozidae).

Insects harbor bacterial endosymbionts that provide their hosts with nutritional benefit or with protection against natural enemies, plant defenses, insecticides, or abiotic stresses. We used directed sequencing of 16S rDNA to identify and compare endosymbionts of Bactericera maculipennis (Crawford) and the western, central, and northwestern haplotypes of B. cockerelli (Šulc) (Hemiptera: Psylloidea: Triozidae).

Comparative Phylogenomic Analysis Reveals Evolutionary Genomic Changes and Novel Toxin Families in Endophytic Pathogens.

pathogens are the causative agents of several severe crop diseases worldwide, including citrus Huanglongbing and potato zebra chip. These bacteria are endophytic and nonculturable, which makes experimental approaches challenging and highlights the need for bioinformatic analysis in advancing our understanding about pathogenesis. Here, we performed an in-depth comparative phylogenomic analysis of the pathogens and their free-living, nonpathogenic, ancestral species, aiming to identify major genomic changes and determinants associated with their evolutionary transitions in living habitats and pathogenicity.

First Report of Curly Top of Caused by in the Columbia Basin of Washington State.

Two fields of coriander ( L.) seed crops of proprietary cultivars were observed in the Columbia Basin of Washington in July 2020 with 40 and 90% incidence of plants showing stunting and leaf and stem discoloration, sometimes with mild leaf curl. Foliar discoloration ranged from yellow to red and purple.

KASP Markers Reveal Established and Novel Sources of Resistance to in Pea Genetic Resources.

(PSbMV) is both seedborne and aphid-transmitted and can cause economic losses for pea ( L.) production by reducing yield through decreased seed weight and number. The P1 pathotype is especially virulent, affecting this important vegetable crop across the United States and internationally in regions of West Asia, North Africa, Europe, and Australia.

Seasonal Population Dynamics of Potato Psyllid (Hemiptera: Triozidae) in the Columbia River Basin.

Understanding factors that affect the population dynamics of insect pest species is key for developing integrated pest management strategies in agroecosystems. Most insect pest populations are strongly regulated by abiotic factors such as temperature and precipitation, and assessing relationships between abiotic conditions and pest dynamics can aid decision-making. However, many pests are also managed with insecticides, which can confound relationships between abiotic factors and pest dynamics.

Development and Validation of KASP Markers for the Identification of Pathotype P1 Resistance in .

As pesticides have become heavily relied on for management of insect pests vectoring economically important pathogens of vegetable crops, development of pathogen-resistant germplasm remains a promising alternative to reduce or eliminate costly and timely chemical inputs. Molecular markers can be used to rapidly identify resistant genotypes to aid breeders in advancing germplasm. This study developed two kompetitive allele-specific PCR (KASP) genotyping markers for rapid screening of genotypes for resistance to pathotype P1 (PSbMV-P1), the most economically devastating strain worldwide.

Growth and Yield Performance of Grown from Seed Potatoes Infected with ' Liberibacter solanacearum' Haplotypes A and B.

Zebra chip (ZC) disease of potato () is associated with infection by ' Liberibacter solanacearum' (Lso). Two haplotypes of Lso-A and B-occur in the United States. Lso haplotype B is more virulent than haplotype A, causing greater disease incidence in tubers, more severe symptoms, and greater loss in tuber yield.