Progress 09/01/23 to 08/31/24
Outputs
Target Audience:The primary audience of the project is the pepper producers in Florida, Georgia, North Carolina, and Ohio. This includes organic and conventional paper producers, packers, shippers, agronomists, crop consultants, farm managers, field workers, seed companies, and dealers; and pepper storage and shipping/transport personnel and companies. Extension faculty, staff, students, post-docs, and researchers are also target audiences. Changes/Problems:For economics, the Qualtrics data did not have a lot of pepper growers. All attempts will be made to increase the sample of pepper growers and include those in the WTP analysis. We expect challenges in data collection as survey grower response rates are notoriously low. What opportunities for training and professional development has the project provided?The student in Economics presented his work on this project at multiple academic conferences. This includes a highly competitive selected paper presentation at the annual Agricultural and Applied Economics Association meetings in July 2024, the leading agricultural economics association. He presented his work to a group of professional agricultural economists, moderated a session, and organized manuscript discussants. This will help prepare him for this dissertation presentation, the job market, and leadership roles in the profession. Huerta (NCSU) used the bacterial spot - pepper pathosystem to teach undergraduate students in Plant Pathology. This project has provided training for a recent Ph.D. graduate in a post-doctoral position. This position has provided training in extension and research for a new Assistant Professor (Huerta). This project has provided training in understanding pathogen genetics and phage isolation for a PhD graduate student. Additionally, we have been able to train 2 graduate and 2 undergraduate students on the synthesis, characterization, and evaluation of nanomaterials as crop protection agents. Moreover, this project has allowed students to travel and present at international conferences where they have networked with other scientists and stakeholders improving their prospects at a career in this field of research. How have the results been disseminated to communities of interest?The results were presented in a conference paper and are publicly available on AgEcon Search (https://ageconsearch.umn.edu/record/344039). Results from product efficacy and a summary of the race structure of strains collected were presented at a grower conference (SE Vegetable Expo) which held approximately 25 attendees. Attendees included crop consultants, vegetable growers, extension agents and administrators, pesticide representatives, and other stakeholders. Information has been disseminated verbally through one-on-one grower visits. The bacterial spot - pepper pathosystem was taught in-person to undergraduate students at North Carolina State University. The pepper chemical experiments were shared at two field days in western North Carolina with a total attendance of at least 300 stakeholders. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, the economics team will focus on increasing the sample size and publishing 2 journal articles: risk analysis and WTP. The team will also participate in the project's extension efforts. An abstract was accepted to the 7th Symposium on Agri-Tech Economics and Sustainable Futures meeting taking place on 28-29 September 2024 at Reading University. We will present virtually. We will continue to evaluate products for efficacy in management of bacterial spot on pepper and isolate and evaluate phages collected from infected pepper plants. Further characterization of bacterial strains and resistant materials will be done.
Impacts
What was accomplished under these goals?
Objective 1. Evaluate risk from endemic and emerging bacterial pathogens (Xanthomonas,PseudomonasandClavibacter) of peppers and develop detection assays to mitigate risks The pepper pathogenic lineage of X. perforans was detected on pepper in North Carolina and on tomato from Oklahoma representing an increase in geographical location. Objective 2. Breeding for resistance We have mapped the recessive resistance genes, bs5 and bs6 to a smaller region in which the resistance genes have been narrowed to one to several candidate genes. The bs5 work by our group was useful in verifying the gene in pepper, which was previously identified by a group in Hungary, by targeting the bs5 homologs in tomato using CRISPR technology. Knockout of the suspected genes in tomato resulted in plants with resistance to X. perforans. As a result, the bs5 gene in pepper was further verified as being the resistance gene. We further investigated the potential mechanism of bs5 resistance and determined its involvement in modulating PAMP-triggered immunity. We also are in the process of looking at stacking recessive gene resistance in pepper by combining different combinations of bs5, bs6 and bs8 with genotypes containg one gene, two genes or all three genes. We have tested these different combinations with X. euvesicatoria, X. garderneri and X. perforans. The genotype containing all three recessive genes had the highest level of resistance. Additionally, we have brought the Charleston Belle x PI308790 F2:3 population for identification of QLT for resistance to X. gardnerii to the F5 generation. GBS data and associated phenotyping data from the F2:3 population have been used to perform QTL analysis. We have identified a putative major QTL and perhaps two minor QTL. Unfortunately, a lack of GBS data 9due to the extreme size of the pepper genome, and only a single full-scale phenotyping trial, the QTL identified are putative and not significant. We will continue to increase the current population to the recombinant inbred stage to fix the genetic loci involved in the associated resistance. In addition, we have started carrying forward a second population using a different resistance source identified in our previous studies. Objective 3. Evaluate novel biologicals, biostimulants, and nanomaterials to manage critical bacterial diseases of peppers and develop novel seed treatments to prevent bacterial pathogen establishment We evaluated more than twenty products for control of bacterial spot of pepper and tomato in two field trials in 2024. Products include nanomaterials and other novel chemistries. We established and maintained four field trials (2 on-farm; 2 research station based) with the same 20 varieties of pepper to: 1) evaluate differences in disease severity across different farms; 2) characterize strains occurring on each farm and variety; and 3) isolate phages from plants with active bacterial spot disease. Significant progress was made in theevaluation in vitro of antimicrobial efficacy and phytotoxicity and mode of action of nanoparticles of combining MgSol with sodium polysulfides (NaPs) in a tank mix will produce a mixture containing small sulfur particulates and magnesium hydroxide nanoparticles (MagSuN). Objective 4. Assess economic feasibility and risk associated with the adoption of new management practices The economics team surveyed specialty crop growers to identify their willingness to pay for pest management mobile applications. These apps include pest risk prediction models and can be used to assess farm-level pest and disease incidence. The survey included a choice experiment and used the generalized mixed logit model to assess the value growers place on pest management smartphone apps and their attributes. Qualtrics was used to collect 250 responses; the team is resuming data collection in addition to these responses. Preliminary results from the generalized multinomial logit preference model suggest that growers regard all attributes of the pest management technology as highly relevant, with estimates being significantly different from zero at the 10% level or lower. Moreover, the significance of tau, which captures the scale heterogeneity of preferences, indicates that growers weigh each attribute differently (Liu et al., 2019). The price estimate is negative and significant at the 1% level. This means that an increase in the price of a smartphone agricultural app reduces growers' utility/preference provided by the choice. Likewise, the alternative specific constant or status quo is negatively significant at the 1% level. This indicates a disutility from not choosing any available smartphone app options. In contrast, the source of information used by the pest management technology, growers have a positive preference for educational/research institutions and private agricultural companies that provide data for pest presence predictions. However, growers prefer educational/research institutions (0.762) to private agricultural companies (0.610), with government agencies as the reference attribute. Past pest presence on farms has a positive and significant coefficient, implying a higher utility/preference by growers when the historic pest feature is included in a choice. Regarding the predictive accuracy of smartphone pest management technology, growers prefer a higher predictive technology option to lower-tier options: the coefficient of 92% accuracy (1.244) is significantly different from the reference case, 77% accuracy. The negative significance of the alternative specific constant (or the status quo) indicates that growers consider smartphone tools as a normal good. This suggests a disutility from not choosing any available smartphone app options. The individual WTP mean estimates illustrate that growers are willing to pay the most for past pest presence consideration ($23.02/month), followed by 92% accuracy ($15.67/month). Growers are willing to pay $187.43/month for smartphone pest management apps. The objectives of the outreach program are to engage and inform decision makers of the project's progress and results through a number of outlets and products including presentations at grower and commodity meetings, field events, social media, a dedicated website, webinar, and other products. Outcome Mapping, a method of program evaluation, will be utilized to assess changes in behavior. Organic and conventional growers will receive recommendations and insights on the efficacy and use of novel compounds, biologicals, and biostimulants in disease management programs, the susceptibility/resistance of cultivars related to current and emerging strains of bacterial pathogens, and economic considerations for making decisions. Novel seed treatments will be targeted to seed producers.
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Subedi, A., Minsavage, G.V., Roberts, P.D., Goss, E.M., Sharma, A. and Jones, J.B., 2024. Insights into bs5 resistance mechanisms in pepper against Xanthomonas euvesicatoria through transcriptome profiling. BMC genomics, 25(1), p.711
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Subedi, A., Nga, N.T.T., Tien, D.T.K., Minsavage, G.V., Roberts, P.D., Goss, E.M. and Jones, J.B., 2024. Draft genomes announcement of Vietnamese Xanthomonas euvesicatoria strains causing bacterial spot on pepper. Access Microbiology, 6(1), pp.000741-v3
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Subedi, A., Minsavage, G.V., Jones, J.B., Goss, E.M. and Roberts, P.D., 2023. Exploring diversity of bacterial spot associated Xanthomonas population of pepper in Southwest Florida. Plant Disease, 107(10), pp.2978-2985
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Parajuli, A., Subedi, A., Timilsina, S., Minsavage, G.V., Kenyon, L., Chen, J.R., Goss, E.M., Paret, M.L. and Jones, J.B., 2024. Phenotypic and genetic diversity of xanthomonads isolated from pepper (Capsicum spp.) in Taiwan from 1989 to 2019. Phytopathology
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Subedi, A., Minsavage, G.V., Roberts, P.D., Goss, E.M., Sharma, A. and Jones, J.B., 2024. Insights into bs5 resistance mechanisms in pepper against Xanthomonas euvesicatoria through transcriptome profiling. BMC genomics, 25(1), p.711
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Sharma, A., Li, J., Wente, R., Minsavage, G.V., Gill, U.S., Ortega, A., Vallejos, C.E., Hart, J.P., Staskawicz, B.J., Mazourek, M.R. and Stall, R.E., 2023. Mapping of the bs5 and bs6 non-race-specific recessive resistances against bacterial spot of pepper. Frontiers in Plant Science, 14,
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Subedi, A., Barrera, L.B.T.D.L., Ivey, M.L., Egel, D.S., Kebede, M., Kara, S., Aysan, Y., Minsavage, G.V., Roberts, P.D., Jones, J.B. and Goss, E.M., 2024. Population Genomics Reveals an Emerging Lineage of Xanthomonas perforans on Pepper. Phytopathology�, 114(1), pp.241-250
|
Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The primary audience of the project is the pepper producers in Florida, Georgia, North Carolina, and Ohio. This includes organic and conventional paper producers, packers, shippers, agronomists, crop consultants, farm managers, field workers, seed companies, and dealers; and pepper storage and shipping/transport personnel and companies. Extension faculty, staff, students, post-docs, and researchers are also target audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One student was trained under this project and graduated with MS degree -Thesis title: Investigating Potential Virulence Genes of Plant Pathogenic Bacterium Pseudomonas syringae pv. syringae Utilizing Whole-genome Sequencing Analysis and Identifying Novel Small Molecule Growth Inhibitors to Manage Pseudomonas Leaf Spot Disease on Pepper Seeds and Seedlings.Graduate date: Dec 2022.The Ohio State University One post-doctoral researcher (0.25 FTE) is currently working on this project to evaluate seed treatment. The Ohio State University. How have the results been disseminated to communities of interest?Eight county extension meetings and two extension trainings were conducted in 2023 to disseminate our findings in Georgia to growers and agricultural industry.. Subedi A, Population genomics of Xanthomonas euvesicatoria of pepper in Southwest Florida, Plant Health 2023, Denver, CO, August 2023. Contributed abstract for research community Wade, T., Amon, K.G, Zhengfei, G., and Frey, C. (2023) A Review of Bell Pepper Production and Price Trends From 2010 to 2022. In review at EDIS. Food and Resource Economics Department, UF/IFAS Extension, Gainesville, FL. Extension publication for growers and extension clientele. Wade, T., Ogisma, L., Amon, K., and Roberts, P. (2023) Risk analysis of a novel bacterial disease management system. Commercial Vegetable Production Research Connections. Available at https://commercialveg.ifas.ufl.edu/research-connections/.Extension publication for growers and extension clientele. Results were shared with growers at multiple events including the NC Fruit and Vegetable Expo (50 attendees in the presentation), Tomato Field Day (100 attendees in the presentation), and the Winter Vegetable Meeting (65 attendees in the presentation). In each session, 50 to 75% of participants expressed the intent to change their practice based on the presentations. One research associate and one graduate student worked on this project (cost-share- student stipend) at Auburn What do you plan to do during the next reporting period to accomplish the goals? Continuation of genomic analysis of bacterial strains and breeding Continuation of field and greenhouse trials for assessing efficacy of products to manage bacterial diseases on pepper Complete the development of the RPA isothermal diagnostic assay in collaboration with Agdia, Inc. Determine the mode of action of the selected SMs in Pss using microscopy analyses. Evaluate lead compounds for seed treatment using nanoparticles - nanopriming/seed coating.
Impacts
What was accomplished under these goals?
Significant progress has been made on all objectives including the characterization of populations of Xanthomonas and Pseudomonas species isolated from across the US, incorporating resistance genes into pepper plants, screening and production of novel products has identified several compounds that show promise in managing bacterial diseases on pepper, efficacy trials, and economic analysis. Objective 1. Goss and Jones (UF) continued genomic analysis of X. euvesicatoria strains collected from pepper. Our analysis shows that novel variation in Florida has previously been documented elsewhere, indicating continued long-distance movement of X. euvesicatoria strains. We also documented mutations in the avrBs2 locus in 51 of 103 genomes of Florida strains, indicating selection for loss of function. The mutations prevent elicitation of hypersensitive response in cultivars carrying the Bs2 resistance gene. Dutta (UGA) Characterized Pseudomonas capsici strains from pepper and tomato; describing a unique bacterium with potent arsenal from Georgia. Pontis (Auburn) received transplant samples for specialty peppers and samples from pepper field containing different resistant cultivars, and specialty peppers. Interestingly, we found that transplant samples (that were heavily infected) contained X. perforans. Whereas pepper field samples contained X. euvesicatoria. We are now analyzing the virulence gene content and phylogenetic placement of X. euvesicatoria and X. perforans. Miller (OSU) Primers to detect P. syringae pv. syringae (Pss) were developed and together with the DNA of Pss and closely related Pseudomonas species have been sent to Agdia Inc. to evaluate their suitability for developing the RPA assay. Objective 2. Our previous work (Hutton, UF) delimited bs6 to just three candidate genes, Ca06g12530, Ca06g12540, and Ca06g12550, and bs8 to a single gene: Ca11g18230. We are now carrying out functional validation of the candidates by CRISPR/Cas9-mediated mutagenesis of their tomato homologs. We have developed CRISPR constructs, and they have been submitted to an external agency for transformation and tissue culture. Once we receive the mutants, we will characterize them to identify the resistance genes. We have also generated near-isogenic populations of pepper variety Early Calwonder carrying all possible combinations of bs5, bs6, and bs8 resistances to evaluate the magnitude of resistance singly or in different combinations against Xanthomonas euvesicatoria, X. perforans, and X. gardneri. In addition, crosses were previously for pyramiding the Bs2, Bs3, bs5, bs6, and bs8 resistance genes into advanced pepper breeding lines for a germplasm release. We have generatedmultiple combinations of these genes using marker assisted selection, and field evaluations of F3 and F4 breeding lines are underway in fall 2023 for selecting lines with better horticultural type. Aastha Recessive gene bs5 was found to be resistant to all Xanthomonas euvesicatoria races. To investigate defense signaling pathways in pepper with recessive resistance, we examined differences in transcriptome composition between a recessive resistance line bs5 and susceptible genotype ECW at 0, 1, 2, and 4 days post-inoculation. We found that many of the differentially expressed genes were classified as potentially defense-related genes linked to pattern recognition receptors (PRRs), mitogen-activated protein kinase (MAPK), calcium signaling. The most differentially expressed genes were identified at two days post inoculation. We are currently testing hypotheses regarding the genetic mechanisms behind this important recessive resistance. In Fall of 2022 and Summer of 2023, pontis (Auburn) conducted phenotyping of 199 F2:3s from Pat Wechter that were obtained upon crossing S6 lines that we provided to him last year for PI line that we have identified as resistant to X. gardneri. The screening was done using both dip inoculation and infiltration methods. These F2:3s have been genotyped by Wechter lab. Objective 3. Several Copper and Magnesium-based nanomaterials (Fixed Quat Copper, MgCu, MgCu Double; see Table 1) were synthesized in Dr. Santra's Lab (UCF)and delivered to Dr. Paret's Lab (UF) to support greenhouse and field trials. Note that these three materials were chosen based on the feedback received from the trial. At NSCU, In 2022, we conducted two replicate field trials evaluating 9 treatments against a nontreated control for efficacy in controlling bacterial spot (Xanthomonase euvesicatoria) on bell pepper. Disease severity and yield were collected. Four of the nine treatments provided better control than the non-treated, although yield was not different among the treatments. Georgia evaluated eight copper products and 3 OMRI-listed products on reducing bacterial spot severity caused by Pseudomonas capsici on pepper. All copper products were able to significantly reduce bacterial spot severity compared with non-treated check plots. Among the OMRI-listed products LifeGuard tends to reduce bacterial spot severity numerically compared with OSO, Serenade and non-treated check but the reduction was not significant.OSU Ten small molecule inhibitors (SM) were effective against copper- and streptomycin-resistant as well as biofilm-embedded Pss and other plant pathogens (n=22) at low concentrations (<200 µM) but had no impact on beneficial phytobacteria (n=12). Furthermore, these SMs showed better or equivalent antimicrobial activity against Pss in infested pepper seeds and inoculated seedlings, compared to copper-sulfate (200 µM) and streptomycin (200 µg/ml). Additionally, none of the SMs were toxic to pepper tissues, human Caco-2 cells, and pollinator honeybees at 200 µM. Overall, the SMs identified in this study are promising alternative antimicrobials for managing PLS in pepper production. Similar studies using the same products were replicated in greenhouse trials at UF (Roberts). The efficacy of biological products was tested against Xanthomonas euvesicatoria on artificially infested California Wonder pepper seeds. Regalia, Howler and Theia significantly reduced disease incidence by 55%, 48% and 45%, respectively, compared to the non-treated control. LifeGard, Stargus and Serenade reduced seed germination by 90%. In a second trial, Serenade ASO, Serifel, LifeGard WG, Stargus, Regalia, Brandt Organics Aleo, Theia, Double Nickel and Howler all reduced disease severity when compared to the non-treated control. Brandt Aleo and Regalia were the best performers, with a disease severity reduction of 50%. A pre-selected library of 4,182 small molecules (SM) was tested against Pss strain SM1042-14R to develop novel seed treatments to prevent bacterial pathogen establishment, Miller, OSU. Objective 4. To assess the economic feasibility and risk associated with the adoption of new management practices to address bacterial spot on bell pepper, the economics team conducted risk assessments for treatments in FL and NC, presented at a horticulture conference, published a proceedings article, and published a local extension document. A related journal article on tools to assess risk in spray programs is drafted, an extension publication on market trends in pepper production is in peer-review, and a survey of growers' willingness to adopt pest management tools is in IRB. Other work in progress relate to the economic and ecological determinants of atrazine in environmental water.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
" Lonege, L., Wade, T., Amon, K.G, & Roberts, P. (2023) Florida Bell Pepper Novel Treatments Profitability Risk Assessments. Proceedings Florida State Horticulture Society.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Anuj Sharma, Jian Li, Rebecca Wente, Gerald V. Minsavage, Upinder S. Gill, Arturo Ortega, C. Eduardo Vallejos, John P. Hart, Brian J. Staskawicz, Michael R. Mazourek, Robert E. Stall, Jeffrey B. Jones, and Samuel F. Hutton. 2023. Mapping of the bs5 and bs6 non-race-specific recessive resistances against bacterial spot of pepper. Frontiers in Plant Science 14: 1061803. doi: 10.3389/fpls.2023.1061803
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Subedi, A., Barrera, L.B.T.D.L., Lewis Ivey, M., Egel, D., Kebede, M., Kara, S., Aysan, Y., Minsavage, G.V., Roberts, P., Jones, J.B. and Goss, E.M., 2023. Population genomics reveals an emerging lineage of Xanthomonas perforans on pepper. Phytopathology, (ja).
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Subedi, A., Minsavage, J., Jones, J.B., Goss, E. and Roberts, P., 2023. Exploring diversity of bacterial spot associated Xanthomonas population of pepper in Southwest Florida. Plant Disease, (ja).
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Ranjit S, Deblais L, Rotondo F, Shannon B, Johnson R, Miller SA, Rajashekara G. 2023 Discovery of novel small molecule growth inhibitors to manage Pseudomonas leaf spot disease on peppers (Capsicum sp.). Plant Dis. May 16. doi: 10.1094/PDIS-12-22-2976-RE. Epub ahead of print. PMID: 37194208.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2023
Citation:
Zhao, M., Gitaitis, R., and Dutta, B. 2023. Characterization of Pseudomonas capsici strains from pepper and tomato; a unique bacterium with potent arsenal. Frontiers in Microbiology
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Liao, Y.Y., Pereira, J., Huang, Z., Fan, Q., Santra, S., White, J.C., De La Torre-Roche, R., Da Silva, S., Vallad, G.E., Freeman, J.H. and Jones, J.B., 2023. Potential of Novel Magnesium Nanomaterials to Manage Bacterial Spot Disease of Tomato in Greenhouse and Field Conditions. Plants, 12(9), p.1832.
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2023
Citation:
Choudhary, M., Pereira, J., Davidson, E.B., Colee, J., Santra, S., Jones, J.B. and Paret, M.L., 2023. Improved persistence of bacteriophage formulation with nano N-acetyl cysteine zinc sulfide and tomato bacterial spot disease control. Plant Disease, (ja).
|
Progress 09/01/21 to 08/31/22
Outputs
Target Audience:The primary audience of the project is organic and conventional pepper producers in Georgia, Florida, North Carolina, Ohio, Alabama, and throughout the US. Additionally, all associated businesses include packers, shippers, agronomists, crop consultants, county agents, farm managers, field workers, seed companies, sales dealers, and pepper storage and shipping/transport personnel and companies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Multiplegraduate students, undergraduate students, and post-doctoral researchers are currently working on this project as recorded in project FTE. Additionally stakeholders and the scientific community have been reached through extension activitites and presentations at scientific conferences. How have the results been disseminated to communities of interest?Tomato Field Day (field day) Aug 2022.200 attendees.Title: Management of Bacterial Spot of Tomato and Pepper Authors: Inga Meadows, Ella Reeves, Ying-Yu Liao, and Alejandra Huerta Winter Vegetable meeting - Feb 2022.60 attendees.Title: Pepper and Cucurbit Disease Management Authors: Inga Meadows, Ella Reeves, Ying-Yu Liao, and Alejandra Huerta Southeast Fruit and Vegetable Expo - Nov 2021.30 attendees.Title: Management of Pepper and Tomato Diseases Author: Inga MEadows, Ying-Yu Liao, Ella Reeves, Alejandra Huerta 07/15/2022 Management of vegetable diseases in fall grown crops (Echols County). Dutta, Georgia. No. attendees 18 09/01/2021 Update on fungal and bacterial diseases in pepper (regional) Dutta, Georgia. Attendees 58 01/08/2022 Update on pepper anthracnose and bacterial spot in Georgia. Dutta. Southeast Fruit and Vegetable Conference (Savannah, GA) What do you plan to do during the next reporting period to accomplish the goals? Progress will continue under the objectives. Rapid pathogen identification will be carried out by examiningPCR conditions testing and probe development for the RPA assay will be carried out in the coming months in collaboration with Agdia Inc. For breeding, (Hutton, UF) will functionally characterize the candidates using CRISPR/Cas9 technology. Gene knockout will be performed in tomato; we will knockout five tomato homologs of threebs6candidates and a single tomato homolog of thebs8candidate. Hutton will perform one additional backcross to improve the horticultural characteristics of this material before putting forward a germplasm release. Wechtercurrently has125 F2 plants in the flower stage which will be selfed to generate F2:3 seed. An addition 80 F2 seeds have been germed and will also be carried to the F2:3 generation. DNA is being isolated from all F2 plants and will be used in FY2022 for genotype by sequencing.As soon as all 200+ F2:3 families are completed from the Charleston Belle x PI308790 F1 cross, the Charleston Belle x PI200725 will be carried to the F2:3 generation. Miller will continue seed therapies by testing the 10 most potent SMs (high antimicrobial efficacy [MBC<200μM] and narrow spectrum of activity) were selected for further studies.Field and greenhouse studies will continue to identify novel compounds for management of bacterial diseases on pepper.
Impacts
What was accomplished under these goals?
Significant progress has been made on all objectives including the characterization of populations of Xanthomonas and Pseudomonas species isolated from across the US. Progress continues to be made on characterizing and incorporating resistance genes into pepper plants. Screening and production of novel products has identified several compounds which show promise in managing bacterial diseases on pepper Objective 1. Goss, (UF) sequenced whole genomes of 96Xanthomonas euvesicatoriastrains and 32X. perforansstrains from Florida pepper farms to determine the extent of genetic variation in the Florida populations. Miller, OSU, generated genomic fingerprints of Ohio pepper strains ofPseudomonas syringaepv. syringae,eight Pss strains from other hosts or the environment (INRA, France) and twoP. syringaepv.aptata(Psa) strains fromBeta vulgaris. Objective 2. Previous work (Hutton, UF) mappedbs6to a 473 Kb interval in chromosome 6. All five genes in the region showed protein-coding polymorphism between susceptible and resistant alleles. Further fine mapping with a F2population of ~11,000 plants delimitedbs6to just three candidate genes: Ca06g12530, Ca06g12540, and Ca06g12550. Hutton lab mappedbs8to a 2.3 Mb interval in chromosome 11. Using a segregating population of ~1000 F2s, the gene delineated into a 21 Kb interval, which contained a single gene: Ca11g18230. We determined that there is a transposon insertion in the 5' UTR of this gene in the bs6candidates and a single tomato homolog of thebs8candidate. Wechter, USDA, identified two pepper plant introductions, PI308790 and PI200725, that were verified to have significant levels of resistance to X. gardnerii were selfed through 6 generations and crossed into the susceptible bell pepper cultivar Charleston Belle. Objective 3. Two field studies were conducted in fall 2021 and spring 2022 (Paret, UF) to evaluate the impact of nanomaterials (Cu-CS, MgO, Mg-DB and MG-Cu),and compared with copper (Kocide 3000) and copper+mancozeb (Mankocide). The most effective treatment in the study was Mankocide which statistically separated from all other treatments. Field trial in summer 2022 (Dutta, UGA) was conducted to evaluate copper products, biologicals and plant defense inducers in 10 different programs againstP. capsiciunder field conditions. Based on the final disease severity, all programs were able to reduce disease severity significantly compared with non-treated control. A pre-selected library of 4,182 small molecules (SM) was tested against Pss strain SM1042-14R to develop novel seed treatments to prevent bacterial pathogen establishment, Miller, OSU. Objective 4. Wade, UF, A statewide pepper budget was developed for Florida (the previous budget was for SW FL). Budgets were collected for Georgia and North Carolina. Risk analysis began.
Publications
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Boufous, S.; Wade, T.; Overview of Carbon Markets and the Potential for Florida Pepper Producers, Conference Proceedings. The 135th Annual Meeting of Florida State Horticultural Society, June 6th, 2022, Sarasota, FL
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Wade, T; Boufous, S., Adoption of Novel Bacterial Diseases Management System: A Risk Analysis, Paper presentation at the 25th Pepper Conference, Sep 28th, 2022, Tucson, AZ
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Liao Ying-Yu, Reeves Ella, Panwala Roshni, Hernandez Kimberly, Ritchie David, Meadows Inga, Huerta Alejandra. Xanthomonad population dynamics and their effect on disease management of bacterial spot of pepper.14th International Conference on Plant Pathogenic Bacteria (ICPPB) - June 2022
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Zhao, M., Koirala, S., Chen, H.C., Gitaitis, R., Kvitko, B., and Dutta. B. 2021. Pseudomonas capsici sp. nov., a plant-pathogenic bacterium isolated from pepper leaf in Georgia, USA. International Journal of Systematics and Evolutionary Microbiology 71:004971
- Type:
Other
Status:
Published
Year Published:
2022
Citation:
Dutta, B., Foster, M.J., and Donahoo, W.M. 2022. Evaluation of biological and chemical products on managing bacterial leaf spot in bell pepper in Georgia, 2020. PDMR 16:V045
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Ying-Yu Liao1, Ella Reeves2, Roshni Panwala1, Kimberly Hernandez1, David Ritchie1, Inga Meadows2, Alejandra I. Huerta. Diversity of Xanthomonad populations and management of bacterial spot disease of pepper in North Carolina
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Boufous, S.; Wade, T.; Florida Farmers Multi-BMPs Adoption: A Survey Analysis, Paper Presentation at the Annual Meeting of the Southern Agricultural Economics Association, February 12-15, 2022, New Orleans, LA (*)
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Boufous, S.; Wade, T.; Florida Farmers Multi-BMPs Adoption: A Survey Analysis, Paper Presentation at the 8th Biennial UF Water Institute Symposium, February 23^d, 2022, Gainesville, FL(*)
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Boufous, S.; Wade, T.; Understanding Farmers Multi-BMPs Adoption: An Analysis of Factors and Complementarity Relationship, Poster Presentation at the 2022 Agricultural and Applied Economics Association Annual Meeting, July 31st- August 2, 2022, Anaheim
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Subedi, Aastha, Population dynamics and genomics of Xanthomonas euvesicatoria of Pepper in Florida 7th Xanthomonas Genomics Conference, Clearwater Beach, Florida, June 2022.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Subedi, Aastha, Expanding populations of Xanthomonas perforans on pepper in Florida Plant Health 2022 Annual Meeting of the American Phytopathological Society, Pittsburgh, Pennsylvania, August 2022.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Ranjit, S., Deblais, L., Rotondo, F., Miller, S. A. and Rajashekara, G. Identification of Novel Small Molecule Growth Inhibitors to Control Pseudomonas Leaf Spot Disease on Pepper Plants. ASM Microbe 2022, Jun 09 - 13, 2022, Washington DC.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
Ranjit, S., Deblais, L., Rotondo, F., Miller, S. A. and Rajashekara, G. Identification Of Novel Small Molecule Growth Inhibitors To Control Pseudomonas Leaf Spot Disease On Pepper Plants. CFAES Annual Research Conference, April 11-14, 2022, Columbus OH
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Ranjit, S., Deblais, L., Rotondo, F., Miller, S. A. and Rajashekara, G. Identification of Novel Small Molecule Growth Inhibitors to Control Bacterial Spot Disease on Pepper Plants. 36th Edward F. Hayes Graduate Research Forum, OSU, March 4th, 2022, Columbus, OH.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Rotondo, F., Amrhein, J., Vargas, A., Taylor, A. and Miller, S. A. Evaluation of strategies to manage bacterial canker and Pseudomonas leaf spot in peppers. PlantHealth 2022, August 6-10, 2022, Pittsburgh, PA.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
1. Pereira, J., Smith S., Huang Z., Holderness A., Strayer A., Liao Y.Y., Myers M.E., Johnson E., Graham J.H., Jones J.B., Paret M.L., Santra S., Nano-Magnesium as an alternative to copper biocide for crop protection , 14th International Conference on Plant Pathogenic Bacteria (ICPPB), Via San Bernardino da Siena, 116 06088 Santa Maria degli Angeli (PG), Assisi, Italy, 3-8 July, 2022.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2022
Citation:
2. Young M., Ozcan A., Rajasekaran P., Strayer A., Liao Y.Y., Myers M. E., Johnson E., Graham J. H., Jones J. B., Paret M. L., Shantharaj D., De La Fuente L., Santra S., Advanced copper and Cu alternatives for crop protection , 14th International Conference on Plant Pathogenic Bacteria (ICPPB), Via San Bernardino da Siena, 116 06088 Santa Maria degli Angeli (PG), Assisi, Italy, 3-8 July, 2022
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Santra, S., Advanced copper and non-copper alternatives for crop protection , Department of Soil Science & Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India, July 29, 2022
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Santra, S., Advanced Anti�Microbial Nanomaterials for Crop Protection , Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, India, July 27, 2022
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Santra, S., Sustainable Agriculture: Importance of Industry Academic Partnership , International Conference On Harnessing Indian Agriculture for Domestic and Global Prosperity, A.P. Shinde Hall NASC, ICAR, New Delhi, India, July 22 23, 2022
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Santra, S. and Pereira J. (co-invited), Improving bioavailability of nanomaterials in plant systems , Nanotechnology in Agriculture Summer School, University of Tuscia (DAFNE), Viterbo, Italy, June 30 - July 1, 2022
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Santra, S., Nanotechnology Tools for Crop Protection , NanoFlorida 2022, University of Florida, Gainesville, FL, April 16-17, 2022
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Santra, S., Advanced Anti-Microbial Nanomaterials for Crop Protection , Florida Association for Nanotechnology International Academy, October 8, 2021
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Santra, S., Advanced Bactericides/Fungicides for Crop Protection , The Connecticut Agricultural Experiment Station (CAES), New Haven, Connecticut, October 27, 2021 (Lockwood Lecture, In-person).
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Anuj Sharma, Gerald V. Minsavage, Upinder S. Gill, Samuel F. Hutton, and Jeffrey B. Jones. 2022. Identification and Mapping of bs8, a Novel Locus Conferring Resistance to Bacterial Spot Caused by Xanthomonas gardneri. Phytopathology 112:8, 1640-1650. doi: 10.1094/phyto-08-21-0339-R
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Anuj Sharma, Jian Li, Rebecca Wente, Gerald V. Minsavage, Upinder S. Gill, Arturo Ortega, C. Eduardo Vallejos, John P. Hart, Brian J. Staskawicz, Michael R. Mazourek, Robert E. Stall, Jeffrey B. Jones, and Samuel F. Hutton. 2022. Mapping of the bs5 and bs6 non-race-specific recessive resistances against bacterial spot of pepper. BioRxiv 2022:509408. doi: 10.1101/2022.09.26.509408
|
Progress 09/01/20 to 08/31/21
Outputs
Target Audience:Primary audience of the project is organic and conventional pepper producers in Georgia, Florida, North Carolina, Ohio, Alabama, and throughout the US. Additionally, all associated businesses including packers, shippers, agronomists, crop consultants, county agents, farm managers, field workers, seed companies, dealers, and pepper storage and shipping/transport personnel and companies. Changes/Problems:Restrictions on research and extension activities were largely eliminated by mid-2021 and, other than trying to make up for the loss of time due to Covid-19 restrictions in 2020, no signifcant problems or major changes are to be reported. What opportunities for training and professional development has the project provided? Date Type of Training and Location (County) Attendance 07/20/2021 Disease management updates for fall vegetables (Colquitt County, Georgia) 47 07/09/2021 Management of fall grown vegetables (Echols County, Georgia) 28 Opportunities for training Genomics for Diagnostics Workshop, May 11-14, 2021, virtual, hands-on, conducted by Dr. Vero Roman-Reyna (Jonathan Jacobs lab, OSU). Eight participants - two OSU, five NCSU and one UF student or scientific staff - were trained in all aspects of metagenomics for bacterial identification. Huerta used the bacterial spot - pepper patho-system to teach undergraduate students in Plant Pathology. This project has provided training in extension for a recent Ph.D. graduate in a post-doctoral research position (Dr. Ying-Yu Liao). Dr. Liao served 8 counties, 12 extension agents, and 9 growers. Dr. Liao also presented her findings in NCSU Entomology and Plant Pathology department seminar and at the 2021 Tomato Field Day where she presented to over 150 attendees. Dr. Liao generated and distributed informative bacterial disease flyers to NC agent via an email lists and has surveyed eight NC counties for bacterial diseases of pepper. This includes collecting plant samples across the state, has provided services to 12 agents and nine growers. The provided service includes but is not limited to 1) diagnosis of plant diseases on-site (farm), 2) provide disease related and NCSU resources information, 3) submitted diseased samples on behalf of growers request, 4) provide timely and tailored feedback to growers and extension agents for collected samples. After sample and data collection, Dr. Liao conducted genetic and phenotypic assays to characterize bacterial isolates by genus, species, race, and resistance profiles. Dr. Liao shared the results with the growers, SCRI teams, and she also presented the result in the NCSU DEPP department seminar. Dr. Liao was also an active participant in the virtual field days of 2020 and physical field day in 2021. This project has provided training in professional development for a recent Ph.D. graduate in a post-doctoral position (Ying-Yu Liao). Dr. Liao leads, schedules, presents, and coordinates monthly meetings for the NCSU working group. This includes coordination among three labs at NCSU (Huerta, Louws, and Meadows Labs); Dr. Liao leads, schedules, presents, and coordinates bi-monthly meetings between University of Florida and NCSU. This includes six labs (Jones, Goss, Roberts, Louws, Meadows, and Huerta). (obj1) Dr. Liao leads, schedules, presents, and coordinates annual meetings between the Ohio State University and NCSU. This includes five labs (Miller, Jacob, Louws, Meadows, and Huerta). (obj1) Dr. Liao leads, schedules, presents, and coordinates annual meetings between the University of Florida, University of Central Florida, and NCSU. This includes six labs (Paret, Jones, Santra, Louws, Meadows, and Huerta). (obj3) Dr. Liao has presented her findings in 2 annual meetings across seven facilities (University of Georgia, University of Florida, NCSU, the Ohio How have the results been disseminated to communities of interest?Scientific publications, presentations at science conferences,popular news articles, extension publications, extension newsletters, and individual consultation with pepper growers. Extension activities were curtailed due to COVID-19 restrictions but have been mostly lifted in the latter part of the grant reporting so these efforts can be resumed. What do you plan to do during the next reporting period to accomplish the goals?Much of the planned work was delayed due to Covid-19 restrications in 2020 that in some cases (Extension activities) extended into 2021. Therefore, the efforts for the next reporting period are to complete all of the planned work for 2020 thrugh 2021 and make progress on the third year's goals Future directions Develop novel control method(s) effective against Pss on pepper A total of 31 novel bactericidal and bacteriostatic SM effective against Pss at 200 µM were identified during the primary screening. These SMs will be selected for further experiments that will be accomplished during 2021 and 2022. We will determine the antimicrobial efficacy of the selected SMs (minimal inhibitory or bactericidal concentration [MIC/MBC]; 50% inhibitory concentration [IC50%]) against all Pss (n=18), biofilm-protected Pss, and antimicrobial resistant Pss. The SMs also be tested on other pathogenic and beneficial plant bacteria to determine the spectrum of activity. The safety of the selected SM will be tested on human cells, plant tissues and pollinators. The best SMs showing a narrow spectrum activity and no toxicity on eukaryotic models will be selected to assess their antimicrobial efficacy on artificially infested pepper seeds and on infected pepper seedlings. Preventive and curative applications will be tested to identify the optimal conditions to control Pss in pepper. For this part of the study, we will also create a bioluminescent Pss strain, which will allow us to monitor the efficacy of the SM treatments in real-time and over time using the in vivo imaging system (IVIS). This technology will also allow us to identify tissues where Pss is less affected by the SM treatments; as a consequence, these inputs will allow optimization of the SM treatment protocol. Create a bioluminescent Pss strain for in planta studies Several attempts to insert the pUWGR4 plasmid containing the Lux operon into Pss were made. Competent cells were obtained after growing Pss SM1042-14R in LB broth for 12 hrs (exponential phase) and washing the cells several times using cold sterile water and 10% glycerol solution. The following electroporation conditions were tested without success: Voltage: 2.5 and 3.2 Kv; Ohm: 200 and 400; Resistance: 25 and 50 uF. We will test the following electroporation conditions (Blanchard et al. 2017): Voltage: 12.5 Kv; Ohm: 400; Resistance: 50 uF. Determine the mode of action of the selected SM against Pss We will determine the mode of action of the selected SM in Pss. Our previous research demonstrated that several SM harboring the two first backbones in Table 2 significantly alter the bacterial cell membrane integrity by creating pores and blebs or by destroying the cell membrane (Deblais et al. 2018; Kathayat et al. 2018). Antimicrobial agents targeting the bacterial cell membrane are deemed to be good candidates for the development of novel control methods because they are less likely to induce resistance mechanisms (Li et al. 2017). Microscopy analyses will be done to confirm if similar phenotypes are observed when Pss is challenged with a lethal dose of SM. Future work: We have completed whole genome sequencing of S7E isolate along with otherX. perforansstrains isolated from infected pepper samples obtained from Alabama fields in 2020 and 2021. The genome analysis of these strains will be conducted. Genome sequence of S7E will be screened for allelic differences/indels in known virulence factors, which might provide clues to its increased ability to infect and grow on X10R pepper genotypes. .
Impacts
What was accomplished under these goals?
Co-PD NCSU group. We surveyed pepper fields for bacterial diseases and were able to collect and characterized 55 strains of bacteria from symptomatic pepper plants across 9 counties in NC before August, 2020. Co-PD Dutta and post-doctoral associate Zhao, UGA, identified a novel bacterial species that is capable of causing disease on pepper and brassica crops in Georgia. Three phytopathogenic bacterial strains Pc19-1, Pc19-2, Pc19-3 were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper (Capsicum annuum) leaves in Georgia, USA. Therefore, we propose a new species Pseudomonas capsici sp. nov., with Pc19-1T (= CFBP 8884T = LMG 32209T) as the type strain. The DNA G+C content of the strain Pc19-1T was 58.4 mol%. Co-PD Goss, Jones. UF. We characterized effector variation in a historical and current collection of X. euvesicatoria (pv. euvesicatoria) strains from Florida, which showed that strains that represent different core genomes lineages differ in effector content, but race may vary within lineages. New strain introductions were likely responsible for past race shifts. These are foundational data for interpreting variation in current populations. Co-PD Goss, PD Roberts, Co-PD Jones. UF. A survey of pepper fields was conducted in south Florida and a collection of bacterial strains was made from bell pepper and specialty pepper types. We phenotyped 527 strains collected from Florida pepper fields in 2019-2021 for species/pathovar, race, copper sensitivity, and streptomycin sensitivity. Most strains were identified as X. euvesicatoria pv. euvesicatoria but we also identified X. euvesicatoria pv. perforans from two farms and pepper transplants. We found variation for copper tolerance within and between farms. Each farm had strains from multiple races and farms differed in race composition. These results suggest the possibility of different pathogen source populations among farms in Florida. Co-PD Miller et al. OSU.Symptomatic pepper leaves were collected from two Ohio counties (Columbiana and Seneca) in 2020.A total of 72 X. euvesicatoria strains were isolated, 31 strains from three fields in Columbiana County and 41 from two fields in Seneca County Pss strains from the OSU culture collection (Miller) were assessed for pathogenicity and virulence on pepper varieties Mercer, Playmaker and Paladin. For the proposed Pss RPA isothermal diagnostic assay, we optimized a species-specific PCR test designed on the HrpZ gene to discriminate P. syringae pv. syringae from other closely related pathovars (coriandricola, tomato, and maculicola) CO-PDs Pontis (Auburn U) and Wechter (USDA). Selfing of USVL-29 and USVL-56 lines for six generations was conducted. Screening of S5 plants against Xg965 showed population homozygous for resistance with disease severity ratings of 0-1.S6 plants of USVL-29 and USVL-56 lines were screened for their resistance potential against emerging Xanthomonas perforans strains (that have shown recent host range expansion on pepper and isolated from infected pepper plants in Alabama). Co-PD Wechter, USDA. A post-doctoral associate was hired for this project and began work on June 10 2021. For this reporting period, Two pepper plant introductions, PI308790 and PI200725, that were identified and verified to have significant levels of resistance to X. gardnerii were selfed through 6 generations and crossed into the susceptible bell pepper cultivar Charleston Belle. The F1 of Charleston Belle x 200725 is currently being selfed to generate F2 seed. The F1 of Charleston Belle x PI308790 was selfed to generate F2 seed. We currently have 125 F2 plants in the flower stage which will be selfed to generate F2:3 seed. An addition 80 F2 seeds have been germed and will also be carried to the F2:3 generation. DNA is being isolated from all F2 plants and will be used in FY2022 for genotype by sequencing. As soon as all 200+ F2:3 families are completed from the Charleston Belle x PI308790 F1 cross, the Charleston Belle x PI200725 will be carried to the F2:3 generation. Co-PD Hutton, UF. Previous research in Hutton's program mapped bs6 to chromosome 6 of pepper, and initial fine mapping located the gene within an approximately 500 Kb interval. In fall 2020, we screened approximately 10,000 backcross F2 plants which were segregating for bs6 to identify additional recombinants for the bs6 interval. These screens identified 71 recombinants, seven of which were highly informative and were advanced as recombinant inbred lines for further testing. These seven RILs, along with six other highly informative RILs identified from previous testing, were phenotyped with X. vesicatoria race 6 to determine response to bacterial spot; additional markers were developed to saturate the bs6 region, and these were used to genotype the 13 RILs. Genotype and phenotype results from these RILs delimited bs6 to a 70 Kb interval. This interval is currently being investigated for bs6 candidate genes and for developing improved markers for aiding selection efforts. CO-PD, Jones, UF, has made significant progress with mapping of a novel resistance gene against Xanthomonas gardneri in pepper accession PI 163192, designated bs8. Following previous work in transfer ofbs8into Early CalWonder background, we have developed up to 7th backcross population, marking the production of near-isogenic line ECW-80R. Using whole-genome sequencing based bulked sequencing analysis, we were able to map the gene to the sub-telomeric region of chromosome 11. Genotyping of the F2 population up to the 5th backcross has delimited the resistance gene within a 2.3 Mb interval. Currently, we are further fine-mapping the gene using approximately 1000 6th backcross F2 population. Furthermore, comparison of bacterial titer between resistant F2 and the susceptible parent showed that the resistance locus causes approximately 9 times reduction inin-plantabacterial population To evaluate the effect of small molecules as seed treatment options against seedborne bacterial pathogens, we assessed the survival of Clavibacter michiganensis subsp. michiganensis (Cmm), Pseudomonas syringae pv. syringae (Pss), and X. hortorum pv. gardneri (Xhg), on artificially infested pepper seeds, The following copper and magnesium based materials were prepared and delivered to Co-PD's to support field trials:Core-Shell Copper (CS-Cu) - this formulation is based on silica nanoparticles incorporated with metallic copper (24,500ppm Cu).Magnesium Copper nanogel (Mg-Cu) - this formulation is based on magnesium hydroxide nanogel substituted with metallic copper (15,000ppm Mg, 5,000ppm Cu).Magnesium Copper double coated (Mg-Cu double) - this formulation is based on the co-precipitation of magnesium nitrate and copper nitrate coated with citrate and n-acetylcysteine (15,000ppm Mg, 5,000ppm Cu). Dutta et al. UGA, Paret et al. UF, and Roberts, UF. Biological and chemical anti-microbial products were evaluated in a spray-program for their efficacy to manage bacterial leaf spot, caused by Xanthomonas euvesicatoria in Georgia. Based on final disease severity and AUDPC, significant differences among the biological and chemical products were not observed except for the Kocide 3000 and Manzate ProStik spray program that had significantly lower AUDPC value compared to other treatments. Phytotoxicity were not observed with any of the products evaluated.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2021
Citation:
Sacristan, S., Goss, E. M, & Eves-Van den Akker, S. (2021). How do pathogens evolve novel virulence activities? Molecular Plant-Microbe Interactions, Published Online:23 Jul 2021, https://doi.org/10.1094/MPMI-09-20-0258-IA
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2021
Citation:
Fernanda Iruegas Bocardo and Anuj Sharma presented work including pepper at virtual Plant Health in 2021. Abstract in press.
- Type:
Conference Papers and Presentations
Status:
Awaiting Publication
Year Published:
2021
Citation:
I. E. Melhus Graduate Student Symposium Award. Ph.D. student, Rishi Bhandari, received this award from the APS Foundation and the I.E. Melhus Graduate Student Symposium Fund to present his research at the symposium entitled Microbial life on a leaf: Building foundation for sustainable agriculture at the Plant Health Annual meeting. Title of his talk: Host genotype affects the microbial community structure on pepper .
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
The results of the study encompassing the characterization and mapping of the novel bacterial spot resistance gene against Xanthomonas gardneri has been submitted for publication to the journal Phytopathology.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Ebrahim Osdaghi 1*, Anuj Sharma 2, Erica M. Goss 2, Peter Abrahamian 2, 3, Eric A. Newberry 4, Neha Potnis 4, Renato Carvalho 2, Manoj Choudhary 2, Mathews L. Paret 5, Sujan Timilsina 2, Gary E. Vallad 3, Jeffrey B. Jones 2* 2021. A centenary for bacterial spot of tomato and pepper. Molecular Plant Pathology, Article DOI: 10.1111/mpp.13125
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Zhao, M., Koirala, S., Chen, H.C., Gitaitis, R., Kvitko, B., and Dutta. B. 2021. Pseudomonas capsici sp. nov., a plant-pathogenic bacterium isolated from pepper leaf in Georgia, USA. International Journal of Systematics and Evolutionary Microbiology DOI 10.1099/ijsem.0.004971
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Shealey, J., Carter, A., Dawson, J., and Dutta, B. 2020. Evaluation of plant defense inducers on managing bacterial leaf spot in bell pepper, Echols County, Georgia, 2019. PDMR 14:V031
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Shealey, J., Carter, A., Dawson, J., and Dutta, B. 2020. Evaluation of plant defense inducers on managing bacterial leaf spot in hot-specialty pepper, Echols County, Georgia, 2019. PDMR 14:V029
|
Progress 09/01/19 to 08/31/20
Outputs
Target Audience: Pepper growers in NC, FL, OH, GA, and AL Scientific society Breeder Stakeholders from chemical and seed industries County extension agents Crop consultants Changes/Problems:Covid-19 pandemic impacted all aspects of this grant including termination of all field trials and delaying arrival of international graduate students. Field trials to evaluate novel compounds were expected to be conducted in spring and summer 2020 in; however, due to the pandemic we were restricted on research activities. Therefore, the activities were limited or not conducted. We plan to conduct this research in the coming years and should be able to complete this objective by grant-end. We also expected to be able to collect more strains of bacteria affecting pepper in NC and other locations; however, again, due to the pandemic, travel has been restricted. We anticipate collecting fewer strains than planned. However, as restrictions are lifted in coming years, we should be able to complete this part of the objective. What opportunities for training and professional development has the project provided? Huerta at NCSU used the bacterial spot - pepper patho-system to teach undergraduate students in Plant Pathology. This project has provided training for a recent PhD graduate in a post-doctoral position. This position has provided training in extension and research for a new Assistant Professor (Huerta) at NCSU. In Georiga, 02/27/2020 Management options for vegetables diseases (Tattnall County) 45 02/17/2020 Fungicide options in diverse vegetable crops (Grady County) 48 02/13/2020 Management of vegetable diseases in North Georgia (Towns County) 23 01/24/2020 Management options in vegetable crops (Colquitt County) 75 01/13/2020 Fungicide options in diverse vegetable crops (Echols County) 34 01/10/2020 Fungicide update in vegetable crops (Regional) 105 How have the results been disseminated to communities of interest? Posters werepresented at a scientific society meeting and extension publications. Information has been disseminated verbally through one-on-one grower visits. The bacterial spot - pepper patho-system was taught in-person. What do you plan to do during the next reporting period to accomplish the goals? Collect strains of bacteria affecting pepper and characterize strains collected in 2020. Evaluate breeding lines in the greenhouse with strains of Xanthomonas euvesicatoria Evaluate novel products to manage bacterial spot in the greenhouse on transplants and in the field. Trials will be conducted in fall 2020 with ten different biologicals, biostimulants, and copper compounds to assess the efficacy of BS control in pepper in Georgia and Florida For the second year of the project, objective 3, we are planning to deliver materials for the field trials and complete the material characterization as proposed.
Impacts
What was accomplished under these goals?
NCSU has begun collecting strains from pepper (Obj. 1) and is also setting up research trials in the greenhouse to evaluate novel products (Obj. 3). Obj1: We recently identified a new bacterial pathogen of pepper in greenhouses/transplant houses in Georgia. The symptoms were aggressive on pepper seedlings and despite copper application the management was quite difficult. Upon identification using biochemical and genetic characterizations, we concluded that the causal agent is Pseudomonas cichorii, not previously reported in pepper in Georgia. P. cichorii strains (n=4) from symptomatic pepper seedlings were collected from greenhouse outbreaks in 2019 and 2020 in Georgia. The 16S rRNA sequence analysis and multilocus sequence analysis (MLSA) using partial gene sequences of gyrB and rpoD confirmed that the Georgia pepper strains were most closely related to P. cichorii. Based on the MLSA, P. cichorii strains from different sources can be divided into two genetically distinct groups. One group includes the type strain from Cichorium endivia (Germany) and strains from Lactuca sativa (UK and Italy), Capsicum sp. (Ethiopia), Solanum tuberosum (India), Lycopersicon esculentum (Turkey), and Cucumis melo (Yugoslavia). The recent Georgia P. cichorii pepper strains clustered in the second group along with strains from Brassica chinensis (Brazil), Brassica oleracea var. capitata (USA), Lactuca sativa (Barbados), Solanum lycopersicum (Florida USA and Tanzania), and Ocimum basilicum (Florida USA). Unlike other bacterial diseases, this new disease is challenging to manage and requires detailed investigation. Control measures such as copper and Actigard (plant defense inducer) applications did not limit the spread of the pathogen in the greenhouse resulting in economic losses.A collection of putative Xanthomonas strains was made from four Florida farms from more than 10 different vrieties of sweet and chile pepper varieties. Obj3.The following copper and magnesium based materials were prepared and delivered for field trial application Core-Shell Copper (CS-Cu) - this formulation is based on silica nanoparticles incorporated with metallic copper (24,500ppm Cu). Magnesium Copper nanogel (Mg-Cu) - this formulation is based on magnesium hydroxide nanogel substituted with metallic copper (15,000ppm Mg, 5,000ppm Cu) Magnesium Copper double coated (Mg-Cu double) - this formulation is based on the co-precipitation of magnesium nitrate and copper nitrate coated with citrate and n-acetylcysteine (15,000ppm Mg, 5,000ppm Cu) Core-Shell Copper (CS-Cu): SEM images showed sub-micron (~500nm) silica spherical particles with uneven coating. The hydrodynamic size of CS-Cu in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of CS-Cu was around 438 d. nm. Magnesium Copper nanogel (Mg-Cu): The hydrodynamic size of Mg-Cu in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of Mg-Cu was around 352 d. nm. SEM image reveled triclinic shaped particles with average diameter of 262.2 ± 31.6 d. nm. Magnesium Copper double coated (Mg-Cu double): The hydrodynamic size of Mg-Cu double in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of Mg-Cu double was around 638.9 d. nm. SEM images revealed particles' clusters, in which particles of around 50nm each were held together. Task 2. Evaluate in vitro antimicrobial efficacy and phytotoxicity Core-Shell Copper (CS-Cu): In vitro antimicrobial efficacy of CS-Cu was evaluated against copper tolerant Xanthomonas perforans strains. After 1h of exposure, CS-Cu at rate of as low as 100μg/mL completely inhibited bacterial growth. Magnesium Copper nanogel (Mg-Cu): The antimicrobial activity of Mg-Cu was tested against Pseudomonas syringae and Xanthomonas alfalfae. Minimal inhibitory Concentration (MIC) of Mg-Cu was 120μg/mL Mg, 40μg/mL Cu for Pseudomonas syringae; and 30μg/mL Mg, 10μg/mL Cu for Xanthomonas alfalfae. Minimal Bactericidal Concentration (MBC) was the same as MIC for both bacteria tested. Magnesium Copper double coated (Mg-Cu double): The antimicrobial activity of Mg-Cu was tested against Pseudomonas syringae and Xanthomonas alfalfae. Both MIC and MBC of Mg-Cu were 120μg/mL Mg, 40μg/mL Cu for Pseudomonas syringae. For Xanthomonas alfalfa, MIC was 60μg/mL Mg, 20μg/mL Cu, and MBC was 120μg/mL Mg, 40μg/mL Cu. The potential plant tissue damage of Mg-Cu was tested on the citrus plant. The testing materials were applied to the citrus plant through the foliar spray, and the potential phytotoxicity symptoms were observed 72 h post-application. Mg-Cu exhibited no plant tissue damage at 800 µg/ml metallic Cu. The following copper and magnesium based materials were prepared and delivered for field trial application based on the demand of other Co-PD's: Core-Shell Copper (CS-Cu) - this formulation is based on silica nanoparticles incorporated with metallic copper (24,500ppm Cu). Magnesium Copper nanogel (Mg-Cu) - this formulation is based on magnesium hydroxide nanogel substituted with metallic copper (15,000ppm Mg, 5,000ppm Cu) Magnesium Copper double coated (Mg-Cu double) - this formulation is based on the co-precipitation of magnesium nitrate and copper nitrate coated with citrate and n-acetylcysteine (15,000ppm Mg, 5,000ppm Cu) Morphological Characterization Core-Shell Copper (CS-Cu): SEM images showed sub-micron (~500nm) silica spherical particles with uneven coating. The hydrodynamic size of CS-Cu in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of CS-Cu was around 438 d. nm. Magnesium Copper nanogel (Mg-Cu): The hydrodynamic size of Mg-Cu in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of Mg-Cu was around 352 d. nm. SEM image reveled triclinic shaped particles with average diameter of 262.2 ± 31.6 d. nm. Magnesium Copper double coated (Mg-Cu double): The hydrodynamic size of Mg-Cu double in DI water was measured through Dynamic Light Scattering. The average hydrodynamic size of Mg-Cu double was around 638.9 d. nm. SEM images revealed particles' clusters, in which particles of around 50nm each were held together. Task 2. Evaluate in vitro antimicrobial efficacy and phytotoxicity (Year 1-4) core-Shell Copper (CS-Cu): In vitro antimicrobial efficacy of CS-Cu was evaluated against copper tolerant Xanthomonas perforans strains. After 1h of exposure, CS-Cu at rate of as low as 100μg/mL completely inhibited bacterial growth. Magnesium Copper nanogel (Mg-Cu): The antimicrobial activity of Mg-Cu was tested against Pseudomonas syringae and Xanthomonas alfalfae. Minimal inhibitory Concentration (MIC) of Mg-Cu was 120μg/mL Mg, 40μg/mL Cu for Pseudomonas syringae; and 30μg/mL Mg, 10μg/mL Cu for Xanthomonas alfalfae. Minimal Bactericidal Concentration (MBC) was the same as MIC for both bacteria tested. Magnesium Copper double coated (Mg-Cu double): The antimicrobial activity of Mg-Cu was tested against Pseudomonas syringae and Xanthomonas alfalfae. Both MIC and MBC of Mg-Cu were 120μg/mL Mg, 40μg/mL Cu for Pseudomonas syringae. For Xanthomonas alfalfa, MIC was 60μg/mL Mg, 20μg/mL Cu, and MBC was 120μg/mL Mg, 40μg/mL Cu. Phytotoxicity The potential plant tissue damage of Mg-Cu was tested on the citrus plant. The testing materials were applied to the citrus plant through the foliar spray, and the potential phytotoxicity symptoms were observed 72 h post-application. Mg-Cu exhibited no plant tissue damage at 800 µg/ml metallic Cu, indicating that the Cu was fixed in the Mg(OH)2 gel system. Objective 4. Economics produced a pepper budget for Florida that is being published on-line. An excel budget sheet for pepper production was produced and will be available on the UF/FRE website.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Liao Y.-Y., Huang Z,. Strayer-Scherer A, Santra S,. White JC, De La Torre-Roche R, Fan Q, Da Silva S, Vallad GE, Freeman JH, Jones JB and Paret ML. 2020. Magnesium-copper alternative to conventional copper for tomato and pepper bacterial spot disease management. APS Annual Meeting, 2020.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Fernanda Iruegas-Bocardo, Sujan Timilsina, Gerald V. Minsavage Jr., Jeffrey B. Jones and Erica M. Goss, 2020. Evolution Xanthomonas euvesicatoria, a major pathogen of pepper. APS Annual Meeting, 2020.
- Type:
Other
Status:
Accepted
Year Published:
2020
Citation:
Tara Wade, Barbara Hyman, and Eugene McAvoy. 2020. Constructing a Southwest Florida Bell Peppers Enterprise Budget. EDIS publication
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Sally A. Miller, Amilcar Vargas, F. Rotondo, R. Khadka and J. Amrhein. 2020. Vegetable Disease Management Research Reports 2019. Tomato, Pepper, Cucumber, Pumpkin, Cabbage, and Cilantro. Ohio Agricultural Research and Development Center (OARDC)
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