Progress 09/01/23 to 08/31/24
Outputs
Target Audience:The target audiences reached during this reporting period include sweetpotato farmers throughout the southeastern United States and California, university Extension agents working in sweetpotato production, sweetpotato industry leaders and commodity organization leadership. Members of the scientific community were also engaged on the project during this reporting period, including plant breeding scientists, plant protection specialists, nematologists, horticulturalists, agronomists, weed scientists, and agricultural economists. A participant segment also benefiting from engagement in this project include research technicians, postdoctoral associates, and students, who gained specialized training and skills development through performing work on the project. ? Changes/Problems:NCSU - (Gorny) Weather conditions and work with grower-cooperators for completion of field experiments continue to remain a challenge; however, we do not anticipate major changes or problems in performing objectives as proposed. NCSU - (Tregeagle) Nothing to report. LSU - Nothing to report. NCSU - (Kudenov) Nothing to report. USVL - Behind schedule due to pandemic restrictions that were in place at USDA, ARS until May 2022 and hiring issues that led to delays in starting research until July 2023. We have been on schedule since research began. UTIA - Nothing to report. What opportunities for training and professional development has the project provided?NCSU - (Gorny) Research technicians Jessica Dotray and Bennett Jeffreys have received training in nematode biology, research techniques, and management through this project. Personnel have also received training and learning opportunities in website development and management using the WordPress platform. Early career scientists and students have been engaged in this project. NCSU - (Jennings) Stephen Ippolito (graduate student)and Dr. Adriana Sanchez-Espindola (Borlaug Fellow visiting from Mexico) has received training in nematode detection research techniques by Gorny's lab. NCSU - (Kudenov) Anh Nguyen (graduate student) has managed and helped to coordinate the greenhouse measurements, field measurements, and data processing of the Raman and UV data. NCSU (Yencho) Simon Fraher, PhD student is receiving training in plant breeding and genomic-assisted breeding as well in nematode biology, research management through this project. Several undergraduate students are engaged in this project and they are also being exposed to plant breeding and plant pathology as well as agricultural research. Several early career scientists (e.g., Dr. Bonny Oloka, Research Scholar) have also been engaged in this project. LSU 2024 (Watson) - A PhD candidate, David Galo, focused his dissertation work on Me and Mi resistance mechanisms in sweetpotato and will graduate in December 2024.My research associate has optimized protocols for root histology and oversees daily team management. How have the results been disseminated to communities of interest?NCSU (Yencho, Gorny, Jennings, Schultheis) - Project results and outcomes have been presented to key stakeholder groups in formal and informal meetings and discussions. During the current reporting period, the SweetARMOR website has been updated with project results. The NCSU team has presented research results to extension stakeholders at two regional sweetpotato production meetings and the NCSU Sweetpotato Field Day. LSU (Watson, Smith, Gregorie, LaBonte, Villordon, Baisakh) - SweetARMOR project results were highlighted by LSU PI's at: theLSU AgCenter Sweetpotato Field Day in Chase, Louisiana (August 328, 2023); the Society of Nematologists meeting in Park City, Utaha (August 2024); the Brazilian Nematological Society meeting in Iguassu Falls, Brazil (September 2024); and via the LSU AgCenter Sweetpotato Virtual Field Day video. What do you plan to do during the next reporting period to accomplish the goals?Goal 1 - Identification of integrated RKN management strategies for SP. (NCSU, LSU, MSU, UCCE) 1.1. Evaluate the impact of poor- and non-host rotational cash and cover crops in suppressing Me and Mi within sweetpotato production systems (NCSU - Gorny, Schultheis). Gorny, Schultheis, and Jennings will continue multi-year field experiments and surveys. Nematode density data will be collected at harvest of rotational crops. Sweetpotatoes at four of the field trial locations will be harvested and evaluated for yield and nematode damage per plot. Soil samples will be collected at the additional sixth site. Data will be analyzed and the effect of rotational crop and cover crop treatments on sweetpotato yield and damage will be explored. 1.2. Evaluate the impact of weed management on field populations of Me and Mi (NCSU - Jennings, Gorny). Weed samples collected in 2024 will be analyzed with molecular species identification and weed species found in association with Me most frequently reported. Additional herbicide crop tolerance studies will be conducted in 2025. A study will be conducted in the greenhouse to evaluate herbicide tolerance of several commercially available sweetpotato varieties and advanced clones. 1.3. Explore integration of chemical nematode management with weed management and cultural control methods including rotational crops, and cover crops (NCSU - Jennings, Gorny, Schultheis). Studies continued in 2024. Goal 2 - Genomic and phenomic studies to introduce RKN resistance into adapted germplasm. (NCSU, LSU, USVL, UTIA) 2.1. Screen and phenotype germplasm to characterize resistance to Me and Mi (NCSU -Yencho, Gorny; LSU - Labonte, Clark; USVL-Wadl, Rutter). Continued in 2024. 2.2. Examine root penetration, nematode development, and histology of infection sites (LSU - Watson). LSU will publish the nematode development work in Phytopathology. The root histology work is being combined with the RNAseq work (Obj. 2.5) and will be submitted as a separate publication. 2.3. Examine sweetpotato root architecture in response to nematode parasitism (LSU - Villordon, Watson). A manuscript has been prepared for submission to HortScience 2.4. Genome-Wide Association Studies (GWAS) for resistance to Mi (USVL - Wadl, Rutter). Continued in 2024. 2.5. RNAseq studies to characterize resistance to Me and Mi (USVL - Wadl, Rutter; LSU - Baisakh, Labonte). Data will be analyzed and a publication prepared, along with the root histology work. Goal 3 - Genomic-assisted breeding of new market-acceptable, RKN-resistant varieties. (NCSU, LSU, USVL, UTIA) 3.1. Conventional breeding and germplasm enhancement for Me and Mi resistance. (NCSU - Yencho; LSU - Labonte; USVL - Wadl). Continued in 2024. 3.2. Exploration of GS in sweetpotato. (NCSU - Yencho; UTIA- Olukolu; USVL - Wadl). Based on our prior bioassay and preliminary KASP studies, we believe MAS for highly heritable traits such as Me and Mi resistance is feasible, and we plan on implementing MAS for Me and Mi resistance during 2023-2025. Clones with high levels of resistance to Me and Mi still need to be combined into backgrounds that have potential as new varieties containing a suite of key traits that farmers, industry stakeholders, and consumers desire. GS can help facilitate this need through reduced cycle times. NCSU has already assembled a training population (TP) for the selection of SP varieties with high levels of RKN resistance and good horticultural traits. These TP materials will be augmented with training data from ca. 200 additional YR 3-6 clones currently in our breeding program. The NCSU and UTIA groups will coordinate data analysis and training for the GS component of this project in coordination with the other PI's. We will also be relying on the expertise and knowledge sharing of GS in sweetpotato with the USDA, ARS sponsored Breeding Insight program at Cornell University which is currently exploring GS for insect resistance in sweetpotato with co-PI Wadl. 3.3. GS Capacity building and access to resources. (NCSU - Yencho; LSU - Labonte; UTIA - Olukolu; USVL - Wadl). The implementation of GS in a breeding program requires skilled technicians, significant breeding operation changes, along with adequate access to genotyping, bioinformatics and statistical tools to navigate the implementation of GS. One of the objectives of this project is to leverage skills and expertise across the breeding programs to help programs transit smoothly. Goal 4. Develop 2D and 3D storage root phenotyping technologies to examine RKN infection on storage root yield and quality. (NCSU, USVL) 4.1. Perform lab studies to determine optical signatures (NCSU - Kudenov, Gorny, Yencho). Examine the data we've collected so far using different methods and analyzing different peak signatures. 4.2. Quantify signatures in the field and from field materials (NCSU - Kudenov, Yencho, Gorny, Schultheis; USVL - Wadl). Examine the field data collected using a different handheld Raman scanner. 4.3. Study gall formation in storage conditions (NCSU - Kudenov, Yencho, Gorny; USVL - Wadl, Rutter). Collect more field data of SPs using a system containing both polarization and 3D cameras. Goal 5. Economic cost-benefit analyses and effective communication of research results. (NCSU, LSU, MSU, UCANR) 5.1. Field days, production meetings, and development of a centralized sweetpotato website for engaging with stakeholders. A project website (www.sweetarmor.org) and X account (@SweetARMOR_Team) were created in YR1 and populated with information regarding this SCRI research and outreach project, sweetpotato crop management, nematode biology and management, and other resources. The website has been updated and expanded in YR2 and additional posts made to the X account. These outreach platforms were shared with stakeholders at Extension events, including the North Carolina Sweetpotato Commission Annual Meeting. They will continue to be updated with project activities, and we will continue to highlight this project at relevant regional and national meetings. 5.1.1. Project information and events. We will continue to highlight this project at relevant regional and national meetings. 5.1.2. National Sweetpotato Collaborators Group information. The SweetARMOR project will be sponsoring SweetARMOR talks at the National Sweetpotato Collaborators Group Annual Meeting in Irving, TX. 5.2: Economic Analyses (NCSU - Tregeagle). The survey and partial budget analysis will be completed in YR4 of the project. 5.2.1. Partial budgeting analysis for promising varieties and control strategies (NCSU - Tregeagle). Alternative control strategies for analysis will be decided in conjunction with project members. Partial budget analysis of these strategies will be completed. 5.2.2. Choice modeling and willingness to pay surveys NCSU (Tregeagle). Pilot survey results will be analyzed. Full survey instrument and distribution strategy will be updated based on pilot results. IRB review and approval for the full survey will be sought. Full survey results will be analyzed and disseminated.
Impacts
What was accomplished under these goals?
Significant advances were accomplished toward our goals in YR3. Regular communication is critical for success, and presentations have been made at field days, commodity and scientific meetings. The cultural management teams have conducted on-farm management trials evaluating the impact of rotation crops and weeds on RKN populations. Breeders have conducted studies to identify and begin breeding and screening for Me/Mi resistance using KASP markers, while our phenotyping teams have established tests examining effects of Me/Mi infection on root yield and quality, and our economics team has created a survey instrument for release in YR4. YR3 accomplishments include the following. Goal 1 - Identification of integrated RKN management strategies for SP. 1.1. Five on-farm field trials investigating rotational and cover crops for Me/Mi management were established or continued. Rotations included soybean, corn, peanut, tobacco, sunn hemp, pearl millet, sorghum, and cotton. Cover crops (oats, wheat, and a fallow control) will be planted Fall'24. Soil samples were collected in Fall'23, Spring'24, and Fall'24 to provide RKN counts under each rotation. 1.2. Weed and soil samples were collected from 20 farm fields to determine the presence of Me/Mi. Work is ongoing to evaluate the presence of RKN in the samples, and herbicide studies were conducted to determine their effect on SP yield and quality. Goal 2 - Genomic and phenomic studies to introduce RKN resistance into adapted germplasm. 2.1. Ten LSU lines are being screened for Me/Mi resistance. NCSU assayed 87 and 200 clones for resistance to Me and Mi, respectively, with 22 R to Me and 122 R to Mi. 2.2. A time-course RKN development study was conducted with Beauregard (Me/Mi susceptible), Jewel (Me/Mi resistant), L14-31 (Me/Mi resistant), L19-65 (Me R/Mi S), and L18-100 (Me S/ Mi R). Clones were inoculated in the GH and RKN development was monitored in roots using acid fuchsin staining. Genotypes resistant to Me showed halted nematode development at the J2-stage, necrotic tissue formation around the nematode, and nematode degradation over time. Genotypes resistant to Mi had fewer J2-stage nematodes entering roots and delayed development of pre-parasitic J2-stage nematodes to mature adult females. Root histological examinations provided further evidence of hypersensitive response in SP genotypes R to Me. 2.3. Compensatory root growth was observed in some genotypes in response to inoculation with Me or Mi; however, this trait was not linked to the susceptibility of the genotype to RKN, suggesting that compensatory root growth is a genotype-specific trait expressed in response to initial invasion of J2-stage nematodes into the root system. 2.4. The USVL team conducted 3 GH experiments to determine Mi resistance for 105 plant introductions, 78 progeny from a Beauregard (Me S/Mi S) x Regal (Me R/ Mi R) population, and 20 breeding selections from the USVL from the USDA SP germplasm collection. 2.5. An RNAseq study characterizing gene expression in select SP genotypes in response to infection with Me and Mi was started. Five SP genotypes listed above, as well as an additional breeding line (L22-107) showing a high level of resistance to Me/Mi were included in the study. Gene expression was analyzed at time points during the infection process. Data from this experiment is being analyzed. Goal 3 - Genomic-assisted breeding of new market-acceptable, RKN-resistant varieties. 3.1. NCSU established a NCII mating design crossing block during winter '23-24 to develop a population to explore GS in SP. Ca. 40% (1,250 clones) of NCSU's seedlings grown in '24 had a Me/Mi R parent. The 80 family NCII population will be harvested Fall'24. Best families will be identified using visual selection and phenotypic breeding values. At least 30 full-sibs from each family will be harvested and advanced, and used to refine the existing GS model (see 3.2). 3.2. In 2024, NCSU planted the 2023 genomic selection (GS23) population in 3 field sites using an augmented row-column planting design to account for environmental heterogeneity. All clones were phenotyped for yield and quality traits, and Me/Mi resistance (see 2.1). Using observational and genomic DArTag (~3K SNP) data from GS23, NCSU developed a genomic prediction model to facilitate genomic selection. This model uses marker data to predict parental breeding values for yield, quality, and Me/Mi resistance. GS and MAS have allowed rapid deployment of the resistance allele for Me. The 2020 GRKN population (GS20) was genotyped using OmeSeq-qRRS, a new NGS genotyping protocol developed by PI-Olukolu. Variant calling, GWAS and GS predictions have been completed, with a total of 50,526 SNPs across 417 F1 progenies (16 parents and 39 families). Parentage based on marker data revealed that progenies clustered within their expected families, while families sharing a parent grouped closely. Previously mapped QTLs were validated. For yield-related traits, the genomic prediction ability (PA) ranged from 18% to 36%. The weight of total US No.1's exhibited the highest PA at 36%. Root quality traits and metabolite content showed high PAs, ranging from 38% to 50%. An additive model was found to be the most important across traits, although models incorporating dominance effects occasionally outperformed. Models using dosage-based SNPs (6x) generally outperformed those using pseudodiploid SNPs (2x). The optimal marker density for genomic prediction across all traits was found to be ca. 5,000-7,000 SNPs, though in some cases, 3,000 SNPs were sufficient. Goal 4. Develop 2D and 3D storage root phenotyping technologies to examine RKN infection on storage root yield and quality. 4.1. Beauregard plants (45) were scanned using Raman spectroscopy bi-weekly for 12 weeks. Five datasets were collected, 1 pre-inoculation and 4 post inoculation. Treatments included: control (no RKN); Me inoculated; and Mi inoculated. Preliminary analyses show that Raman spectroscopy reveals small differences between RKN +/- samples in terms of means and overall distributions. However, a better machine learning model to distinguish between samples is needed. 4.2. Data collection for the Whiteville field study concluded. SP plots with treatments replicated 4x (66 total) were evaluated. Data analysis is underway. 4.3. SP roots with severe galls were mixed with healthy SP's at a packing house and images of the SP's on the conveyor belt were captured using a polarization camera, with roots in the images labeled as gall + or -. The images were used to train an artificial intelligence (AI) RKN detection model. The model can detect galled SPs, but predictions are affected by the surface variation (roughness) of the SPs. More analyses are needed to refine this model. Goal 5. Economic cost-benefit analyses and effective communication of research results. 5.1. A SP enterprise budget for North Carolina was prepared for crop year 2024, this will form the basis of partial budgeting analysis of alternative control strategies, to be evaluated in YR4. 5.2. Pilot survey development was completed in YR3. IRB approval (exempt status) was sought and received from NCSU's IRB. The choice experiment in the pilot survey was optimized for a small sample (20-30 respondents). Informal agreements were reached with stakeholder associations to assist with distributing the full survey in winter, YR4, after a pilot survey is completed.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Fraher, S.P., Watson, M., Nguyen, H., Moore, S., Lewis, R.S., Kudenov, M., Yencho, G.C., and Gorny, A.M. 2024. A comparison of three automated root-knot nematode egg counting approaches using machine learning, image analysis, and a hybrid model. Plant Disease. DOI: doi.org/10.1094/PDIS-01-24-0217-SR
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Galo, D., Santos Rezende, J., La Bonte, D.R., Watson T.T. (2024). Identification of combined resistance to Meloidogyne enterolobii and M. incognita in sweetpotato genotypes. Plant Disease. doi.org/10.1094/PDIS-03-24-0650-RE
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Ballance, S., Batts, T., Griggin, C., Eure, E., Rayburn, L., Stevens, M, and Thornton, A. Display. 2023 North Carolina Sweetpotato Field Day, Oct. 5, Clinton, NC
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Batts, T., Ballance, S., Griffin, C., Eure, E., Rayburn, L, Stevens, M, and Thornton, A. 2023. Field Presentation. 2023 North Carolina Sweetpotato Field Day, Oct. 5, Clinton, NC
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Baker, H., Wram, C., Wadl, P. A., and Rutter, W. B. 2024. Screening Sweetpotato Germplasm for Resistance to Meloidogyne incognita. (poster). Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Dhungana, A., Power, I., Watson, T., DeRobertis, C., Wadl, P., and LaBonte, D.2024. Genome Wide Association Study to Analyze the Genetic Variation of Fusarium wilt and Root knot Nematode (Meloidogyne incognita) Resistance in Louisiana Sweetpotato Population. (Poster). Presented at The 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Fraher, S., Nguyen, H., Watson, M., Yencho, G.C., Kudenov, M., and Gorny, A. 2024. Digital Phenotyping from Micro to Macro: New Opportunities for Sweetpotato Breeding at NCSU. Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Galo, D., Rezende, J.S., Labonte, D.R., and Watson, T. 2024. Mechanisms of Resistance to Meloidogyne enterolobii and M. incognita on Sweetpotato Breeding Lines. Presented at The 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Other
Status:
Accepted
Year Published:
2023
Citation:
Gorny, A., Jeffreys, B, Dotray, J., Yencho, C., Schultheis, J., and Kudeno, M. Field Presentation. 2023 North Carolina Sweetpotato Field Day, Oct. 5, Clinton, NC
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Ippolito S.J., Jennings, K.M., Monks, D.W., Jordan, D.L., Gorny, A.M., and Moore, L.D. 2024. Evaluating Sweetpotato (Ipomoea batatas) Tolerance to Herbicides Applied Post-transplant. In Proceedings of WSSA 64th annual meeting. San Antonio, TX: WSSA
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Ippolito, S.J., Jennings, K.M., Monks, D.W., Gorny, A.M., Moore, L.D., and Jordan, D.L. 2024. Response of Sweetpotato (Ipomoea batatas) to Herbicides Applied Post-transplant. Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Nguyen, H., Nguyen, A., Pena, E., and Kudenov, M. Detecting Nematode Gall Damage on Packing Lines. Field Presentation. 2023 North Carolina Sweetpotato Field Day, Oct. 5, Clinton, NC
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Stickley, B., Schultheis, J., Gorny, A.M., Dotray, J. and Parker, B. 2024. Rotation/Cash Crop Field Studies to Help Understand the Management of Guava Root Knot Nematode in Sweetpotatoes. Poster. 2023 North Carolina Sweetpotato Field Day, Oct. 5, Clinton, NC
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Stickley, B., Schultheis, J., Gorny, A., Dotray, J., and Parker, B. 2024. Rotation and Cover Crop Field Studies in 2022-2023 for the Management of Guava Root Knot Nematode (Meloidogyne enterolobii) in Sweetpotatoes. Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Stoddard, C.S., and Ploeg, A.T. 2024. Nematicide Efficacy and Variety Resistance in Sweetpotatoes. Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Watson, T. 2024. From discovery to development of host resistance: the story of Meloidogyne enterolobii in Louisiana. Presented at the Society of Nematologists Annual meeting, Park City, Utah. August 8, 2024
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Watson, T. 2024. Nematodes in sweetpotato in the USA. Presented at the Sociedad Brasileira De Nematologia meeting, Iguazu Falls, Brazil. September 5, 2024.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Yencho, G.C. 2024. SweetARMOR Update: Progress and Future Research Plans. Presented at the 48th Annual Meeting of the National Sweetpotato Collaborators Group (NSCG). New Orleans, LA. Jan. 19-20. 2024.
|
Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The target audiences reached during this reporting period include sweetpotato farmers throughout the southeastern United States and California, university Extension agents working in sweetpotato production, sweetpotato industry leaders and commodity organization leadership. Members of the scientific community were also engaged on the project during this reporting period, including plant breeding scientists, plant protection specialists, nematologists, horticulturalists, agronomists, weed scientists, and agricultural economists. A participant segment also benefiting from engagement in this project include research technicians, postdoctoral associates, and students, who gained specialized training and skills development through performing work on the project. ? Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?NCSU - (Gorny) Research technicians Jessica Dotray and Bennett Jeffreys have received training in nematode biology, research techniques, and management through this project. Personnel have also received training and learning opportunities in website development and management using the WordPress platform. Early career scientists and students have been engaged in this project. NCSU - (Jennings) Stephen Ippolito (graduate student)and Dr. Adriana Sanchez-Espindola (Borlaug Fellow visiting from Mexico) has received training in nematode detection research techniques by Gorny's lab. NCSU - (Kudenov) Anh Nguyen (graduate student) has managed and helped to coordinate the greenhouse measurements, field measurements, and data processing of the Raman and UV data. NCSU (Yencho) Simon Fraher, PhD student is receiving training in plant breeding and genomic-assisted breeding as well in nematode biology, research management through this project. Several undergraduate students are engaged in this project and they are also being exposed to plant breeding and plant pathology as well as agricultural research. Several early career scientists (e.g., Dr. Bonny Oloka, Research Scholar) have also been engaged in this project. LSU 2023 (Watson) - A PhD student, David Galo, is focusing his dissertation work on Me and Mi resistance mechanisms in sweetpotato. In 2023, two international interns from Honduras assisted with greenhouse studies exploring root architecture response to nematode parasitism and nematode development in resistant sweetpotato genotypes. They have learned how to analyze roots for architecture attributes using a root scanner as well as stain roots using acid fuchsin. My postdoctoral research associate has optimized protocols for root histology and oversees daily team management. How have the results been disseminated to communities of interest?NCSU (Yencho, Gorny, Jennings, Schultheis) - Project results and outcomes have been presented to key stakeholder groups in formal and informal meetings and discussions. During the current reporting period, the SweetARMOR website has been updated with project results. Gorny has presented research to academic audiences at the 2023 Annual Meeting of the Society of Nematologists in Columbus, OH and the 2023 Annual Meeting of the American Phytopathological Society in Denver, CO, and presented results to extension stakeholders at two regional sweetpotato production meetings and the NCSU Sweetpotato Field Day. Yenchp presented the SweetARMOR project as an invited plenary speaker at the US SweetPotato Council's Annual Meeting, hosted by the NC Sweetpotato Commission during Jan. 22-24, 2023. LSU (Watson, Smith, LaBonte, Villordon, Baisakh) - SweetARMOR project results were highlighted by LSU PI's at: the Phytosanitary Workshop at the Society of Nematologists conference in Anchorage, Alaska (September 28, 2022); LSU AgCenter Sweetpotato Field Day in Delhi, Louisiana (August 31, 2023); the National Sweetpotato Collaborators Group meeting in Wilmington, North Carolina (January 2023); the American Phytopathology Society meeting in Denver, Colorado (August 2023); and via the LSU AgCenter Sweetpotato Virtual Field Day video. What do you plan to do during the next reporting period to accomplish the goals?Obj 1. Development of systems-based sweetpotato crop management solutions for Me and Mi (NCSU, LSU, MSU, UCCE) Obj. 1.1. Evaluate the impact of poor- and non-host rotational cash and cover crops in suppressing Me and Mi within sweetpotato production systems (NCSU - Gorny, Schultheis). Gorny, Schultheis, and Jennings will continue multi-year field experiments and surveys. Nematode density data will be collected at harvest of rotational crops. Sweetpotatoes at one of the field trial locations will be harvested and evaluated for yield and nematode damage per plot. Data will be analyzed and the effect of rotational crop and cover crop treatments on sweetpotato yield and damage will be explored. Obj. 1.2. Evaluate the impact of weed management on field populations of Me and Mi (NCSU - Jennings, Gorny). Weed samples will be collected from many commercial farms several times throughout the season in 2024. Additional herbicide crop tolerance studies will be conducted in 2024. Obj. 1.3. Explore integration of chemical nematode management with weed management and cultural control methods including rotational crops, and cover crops (NCSU - Jennings, Gorny, Schultheis). Studies continued in 2024. Obj 2. Accelerate breeding efforts for resistance to Me and Mi by identifying causal genes/QTL and deploying marker-assisted genomic selection (NCSU, LSU, USVL, UTIA) Obj. 2.1. Screen and phenotype germplasm to characterize resistance to Me and Mi (NCSU -Yencho, Gorny; LSU - Labonte, Clark; USVL-Wadl, Rutter). Continued in 2024. Obj. 2.2. Examine root penetration, nematode development, and histology of infection sites (LSU - Watson). LSU will repeat the greenhouse experiment to confirm the reproducibility of the results from experiment 1 and will conduct additional microtomy and electron microscopy to examine feeding site degradation in Me-resistant sweetpotato genotypes. Obj. 2.3. Examine sweetpotato root architecture in response to nematode parasitism (LSU - Villordon, Watson). Manuscript published during YR3. Obj. 2.4. Genome-Wide Association Studies (GWAS) for resistance to Mi (USVL - Wadl, Rutter). Continued in 2024. Obj. 2.5. RNAseq studies to characterize resistance to Me and Mi (USVL - Wadl, Rutter; LSU - Baisakh, Labonte). Continued in 2024. Obj 3. Deployment of conventional, marker-assisted breeding and/or genomic selection to develop new market ready varieties to Me and Mi (NCSU, LSU, USVL, UTIA) Obj. 3.1. Conventional breeding and germplasm enhancement for Me and Mi resistance. (NCSU - Yencho; LSU - Labonte; USVL - Wadl). Continued in 2024. Obj. 3.2. Exploration of GS in sweetpotato. (NCSU - Yencho; UTIA- Olukolu; USVL - Wadl). Based on our prior bioassay and preliminary KASP studies, we believe MAS for highly heritable traits such as Me and Mi resistance is feasible, and we plan on implementing MAS for Me and Mi resistance in 2023-2024, a year ahead of our original schedule. Clones with high levels of resistance to Me and Mi still need to be combined into backgrounds that have potential as new varieties containing a suite of key traits that farmers, industry stakeholders, and consumers desire. GS can help facilitate this need through reduced cycle times. NCSU has already assembled a training population (TP) for the selection of SP varieties with high levels of RKN resistance and good horticultural traits. These TP materials will be augmented with training data from ca. 200 additional YR 3-6 clones currently in our breeding program. The NCSU and UTIA groups will coordinate data analysis and training for the GS component of this project in coordination with the other PI's. We will also be relying on the expertise and knowledge sharing of GS in sweetpotato with the USDA, ARS sponsored Breeding Insight program at Cornell University which is currently exploring GS for insect resistance in sweetpotato with co-PI Wadl. Obj. 3.3. GS Capacity building and access to resources. (NCSU - Yencho; LSU - Labonte; UTIA - Olukolu; USVL - Wadl). The implementation of GS in a breeding program requires skilled technicians, significant breeding operation changes, along with adequate access to genotyping, bioinformatics and statistical tools to navigate the implementation of GS. One of the objectives of this project is to leverage skills and expertise across the breeding programs to help programs transit smoothly. Obj 4. Develop high-throughput 2D and 3D storage root phenotyping technologies for the examination of nematode infection and storage root yield and quality (NCSU, USVL) Obj. 4.1. Perform lab studies to determine optical signatures (NCSU - Kudenov, Gorny, Yencho). Continued in 2024. Obj. 4.2. Quantify signatures in the field and from field materials (NCSU - Kudenov, Yencho, Gorny, Schultheis; USVL - Wadl). Continued in 2024. Obj. 4.3. Study gall formation in storage conditions (NCSU - Kudenov, Yencho, Gorny; USVL - Wadl, Rutter). Continued in 2024. Obj 5. Economic cost-benefit analyses and effective communication of research results (NCSU, LSU, MSU, UCANR) Obj. 5.1. Field days, production meetings, and development of a centralized sweetpotato website for engaging with stakeholders. A project website (www.sweetarmor.org) and Twitter account (@SweetARMOR_Team) were created in YR1 and populated with information regarding this SCRI research and outreach project, sweetpotato crop management, nematode biology and management, and other resources. The website has been updated and expanded in YR2 and additional posts made to the Twitter accout. These outreach platforms were shared with stakeholders at Extension events, including the North Carolina Sweetpotato Commission Annual Meeting. They will continue to be updated with project activities, and we will continue to highlight this project at relevant regional and national meetings. Obj. 5.1.1. Project information and events. We will continue to highlight this project at relevant regional and national meetings. Obj. 5.1.2. National Sweetpotato Collaborators Group information. The SweetARMOR project will be sponsoring SweetARMOR talks at the National Sweetpotato Collaborators Group Annual Meeting in New Orleans, LA. This meeting will be held in conjunction with the US Sweet Potato Council Meeting which is hosted by the LA Sweetpotato Commission. Obj. 5.2: Economic Analyses (NCSU - Tregeagle). The survey instrument and sampling frame will be finalized and the survey will be conducted in year 3. Obj 5.2.1. Partial budgeting analysis for promising varieties and control strategies NCSU (Tregeagle). Will begin preparing baseline sweetpotato production budgets. Obj 5.2.2. Choice modeling and willingness to pay surveys NCSU (Tregeagle). YR 4 activity.
Impacts
What was accomplished under these goals?
Significant advances were accomplished toward our 5 goals in YR2. Communication is critical for project success, thus our team meets monthly, our AB quarterly, and news updates are posted on our website. Many SweetARMOR extension and research talks have been made at field days, commodity and scientific meetings. The cultural management teams have conducted on-farm, RKN management trials testing the impact of rotation crops in suppressing RKN, while our weed scientists have studied the effect of weeds on RKN. Our efforts are focused on implementing systems-based RKN control methods in farm fields soon. Longer-term, breeders have been conducting studies to identify and breed Me/Mi resistant germplasm. Screening for Me/Mi resistance using KASP markers has begun, this likely represents the 1st use of MAS in SP. Our phenotyping teams have established tests examining RKN infection, root yield and quality. Last, our economics team has reviewed economic analyses of specialty crops, creating a foundation for development of a survey instrument in YR3.YR2 accomplishments by goal include the following. Goal 1 - Identification of integrated RKN management strategies for use in SP crop systems. Obj. 1.1. Five on-farm field trials investigating rotational and cover crops for management of Me were established or continued. Rotations including soybean, corn, peanut, tobacco, sunn hemp, pearl millet, sorghum, and cotton, were planted spring'23 in strip plots. Cover crops (oats, wheat, and a fallow control) will be planted Fall'23. Soil samples will be collected in Fall'23, Spring'24, and Fall'24 to provide RKN count data under each rotational by cover crop combination. Obj. 1.2. Weed and soil samples were collected from 20 commercial fields to determine the presence of Me/Mi. Work is ongoing to evaluate the presence of RKN in the samples. Herbicide studies were conducted to determine the effect of herbicides on SP and yield and quality. Goal 2 - Genomic and phenomic studies focused on introducing RKN resistance into adapted SP germplasm. Obj. 2.1. Fifteen LSU AgCenter breeding lines were screened for Me/Mi resistance. Of these, 7 were resistant to Me, 5 were resistant to Mi, and 3 were Me/Mi resistant. A total of 52 NCSU lines were screened for Me/Mi resistance: 28 were top breeding value progeny of the genomic selection population, and the remaining were elite breeding lines and GS parents, with 10 were resistant to Me and 38 resistant to Mi based on RF score. An additional 87 clones are under evaluation. Obj. 2.2. A time-course RKN development study was conducted with Beauregard (Me/Mi susceptible), Jewel (Me/Mi resistant), L14-31 (Me/Mi resistant), 19-65 (Me R/Mi S), and 18-100 (Me S/ Mi R). Each clone was inoculated in the GH and RKN development was monitored in roots using acid fuchsin staining during the infection process. Genotypes resistant to Me showed halted nematode development at the J2-stage, necrotic tissue formation around the nematode, and subsequent nematode degradation as time progressed. Genotypes with resistance to Mi had fewer J2-stage nematodes entering roots and delayed development of pre-parasitic J2-stage nematodes to mature adult females. This experiment will be repeated in 2024. Obj. 2.3. Data were analyzed from two GH experiments to examine the impact of RKN infection on root architecture traits on the 5 genotypes listed in Obj. 2.2. Compensatory root growth was observed in some genotypes in response to inoculation with Me or Mi; however, this trait was linked to the susceptibility of the genotype to RKN, suggesting that compensatory root growth is a genotype-specific plant trait expressed in response to initial invasion of J2-stage nematodes into the root system. Obj. 2.4. Three GH experiments were completed in 2022-2023 by the USVL team to determine Mi resistance for 105 plant introductions from the USDA SP germplasm collection. Obj. 2.5. An RNAseq study characterizing gene expression in select SP genotypes in response to infection with Me and Mi was initiated in late-August 2023. Five SP genotypes listed in Obj. 2.2. above, as well as an additional breeding line (22-107) showing a high level of resistance to Me and Mi were included in the study. Gene expression will be analyzed at various time points during the infection process. The entire experiment will be performed twice. Goal 3 - Genomic-assisted breeding of new market-acceptable, RKN-resistant varieties. Obj. 3.1. A paired-cross crossing block was established at NCSU during winter 2023 using clones with Me/Mi resistance from USDA, LSU, and Africa. Selections from the GS training population, as well as elite lines testing resistant (bioassay and KASP) were included. Many seedlings were potentially resistant to Me/Mi. Of the 28,518 seedlings evaluated during 2022, 24,410 (85%) were focused on either Me, Mi or both. USVL - The USVL team harvested seed from two polycross nurseries including clones with Me/Mi resistance along with insect resistance. LSU - Six breeding lines from 2022 selections were found to be GRKN resistant, and two breeding nurseries with Me/Mi resistant parents were planted in 2023. Obj. 3.2. Library preparation, SNP calling, and SNP filtering are now complete, but a large number of samples (28%) had low read depth due to poor digestion of DNA samples. The library preparation will be repeated and optimized to ensure uniform coverage across samples. While a total of 140,556 SNPs were identified, only ca. 5K SNPs were retained (missingness rate <= 0.3). Initial GWAS analysis confirmed yield-related traits are controlled by small effects QTL, while the range of genomic prediction accuracies were similar to previously published estimates. Goal 4. Develop high throughput 2D and 3D storage root phenotyping technologies for the examination of RKN infection and storage root yield and quality. Obj. 4.1. A second GH study was done to replicate last year's study. In this trial, 30 SP plants of Beauregard were examined using Raman spectroscopy of leaf samples on a bi-weekly basis for 12 weeks. Six datasets were collected, 1 pre-inoculation and 5 post inoculation. Treatments included: control (no RKN); Me inoculated; and Mi inoculated. Results show that Raman spectroscopy can detect RKN damage, though there seems to be a threshold when the model performs best. Obj. 4.2. Data collection for the 2nd field study in Whiteville, NC concluded Sep. 6, 2023. Sixty-six plots of Beauregard were analyzed, with 16 treatments applied. Treatments were replicated 4 times. The field was planted on Jun. 20, 2023, with data collected on Aug. 9 and Sep. 7, 2023, results are still being summarized. Obj. 4.3. SP roots with severe galls were mixed with healthy SP's at a local packing house and images of the SP's on the conveyor belt were captured using a polarization camera, with SP roots in the images labeled as gall + or -. The image data were then used to train 3 different artificial intelligence-base (AI) RKN detection methods. The results of these studies are still being analyzed. Goal 5. Economic cost-benefit analyses and effective communication of research results. Obj 5.2.2. Initial work on survey development was conducted in YR1, providing information for development of the YR2 survey instrument, which is currently being finalized.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Kilduff, Alice and Daniel Tregeagle. 2022. Willingness-to-Pay for Produce: A Meta-Regression Analysis Comparing the Stated Preferences of Producers and Consumers. Horticulturae. 8(4), 290.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Saha, N., Schwarz, T., Mowery, S., and A.M. Gorny. 2023. Reaction of winter cover crops to Meloidogyne enterolobii and glasshouse bioassay to evaluating utility in managing M. enterolobii in soybean. Journal of Nematology 55:Pp. https://doi.org/10.2478/jofnem-2023-0014
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2022
Citation:
Fraher, Simon. 2022. Advancing Molecular Tools for the Accelerated Release of Root-Knot Nematode Resistant Sweetpotato Varieties. M.S. Thesis, NC State University. 118pp. https://www.lib.ncsu.edu/resolver/1840.20/39564
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Galo D Rezende JS, Clark CA, Labonte DR and Watson T. 2022. Sweetpotato breeding line resistance to Meloidogyne enterolobii and M. incognita (abstr). Presented at the National Sweetpotato Collaborators Group Annual Meeting/SE Region ASHS Annual Meeting, New Orleans, LA. Feb. 11-13, 2022. HortScience 57(9):S278.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2023
Citation:
Fraher S, Schwarz T, Heim C, de Siqueira Gesteira G, Mollinari M, da Silva Pereira G, Zeng ZB, Brown-Guedira G, Gorny A, Yencho G. 2023. Discovery of a major QTL for sweetpotato resistance to the guava root-knot nematode (Meloidogyne enterolobii) (abstr). Presented at the National Association of Plant Breeding Annual Meeting, Greenville, SC, July 11-16, 2023.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Galo, D., Santos Rezende, J., LaBonte, D.R., Watson, T. 2023. Response of sweetpotato breeding lines to Meloidogyne enterolobii and M. incognita parasitism. Oral presentation at American Phytopathological Society meeting in Denver, Colorado August 2023 (abstract published in Plant Disease).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Galo, D., Villordon, A., Clark, C.A., LaBonte, D., Watson, T. 2023. Root architectural response to parasitism by Meloidogyne enterolobii and M. incognita in sweetpotato genotypes. Oral presentation at National Sweetpotato Collaborators Group Meeting in Wilmington, North Carolina February 2023
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Galo, D., Villordon, A., LaBonte, D., Clark, C.A., Watson, T. 2023. Variation in root architectural response of three sweetpotato genotypes to parasitism by Meloidogyne enterolobii and M. incognita. Oral presentation at Society of Nematologists meeting in Anchorage, Alaska September 2022 (abstract published in Journal of Nematology).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Gorny, A.M., Jeffreys, P.B., Dotray, J., Stickley, B., and J. Schultheis. 2023. Chemical and cultural management of Meloidogyne enterolobii in sweetpotato in North Carolina: Current results and future challenges. 2023 Annual Meeting of the American Phytopathological Society. Denver, CO. August 12-16, 2023. (abstract published in Plant Disease)
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Yencho, G. C. 2023. SweetARMOR - Sweetpotato Advanced Resistance and Management for RKN. Presented at the National Sweetpotato Collaborators Group/ US Sweet Potato Council Annual Meeting, Wilmington, NC. Jan. 20 25, 2023.
|
Progress 09/01/21 to 08/31/22
Outputs
Target Audience:The target audiences reached during this reporting period include sweetpotato farmers throughout the southeastern United States and California, university Extension agents working in sweetpotato production, sweetpotato industry leaders and commodity organization leadership. Members of the scientific community were also engaged on the project during this reporting period, including plant breeding scientists, plant protection specialists, nematologists, horticulturalists, agronomists, weed scientists, and agricultural economists. A participant segment also benefiting from engagement in this project include research technicians, postdoctoral associates, and students, who gained specialized training and skills development through performing work on the project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?NCSU - (Gorny) Research technicians (Samantha Mowery) and undergraduate students (Kelci Cox, Grace Artus) have received training in nematode biology, research techniques, and management through this project. Personnel have also received training and learning opportunities in website creation and management using the WordPress platform. Early career scientists have been engaged in this project. NCSU - (Jennings) Stephen Ippolito (graduate student)and Dr. Adriana Sanchez-Espindola (Borlaug Fellow visiting from Mexico) has received training in nematode detection research techniques by Gorny's lab. NCSU - (Kudenov) Anh Nguyen (graduate student) has managed and helped to coordinate the greenhouse measurements, field measurements, and data processing of the Raman and UV data. NCSU (Yencho) Simon Fraher, PhD student is receiving training in plant breeding and genomic-assisted breeding as well in nematode biology, research management through this project. Several undergraduate students are engaged in this project and they are also being exposed to plant breeding and plant pathology as well as agricultural research. Several early career scientists (e.g., Dr. Bonny Oloka, Research Scholar) have also been engaged in this project. LSU - (Watson) A PhD student, David Galo, is focusing his dissertation work on Me and Mi resistance mechanisms in sweetpotato. Three international interns from Honduras have assisted with greenhouse studies exploring root architecture response to nematode parasitism. They have learned how to set up greenhouse experiments and analyze roots for architecture attributes. My postdoctoral research associate, Dr. Josie Santos Rezende, has learned new techniques in root histology. How have the results been disseminated to communities of interest?NCSU - (Yencho and Gorny) Project results and outcomes have been presented to key stakeholder groups in formal and informal meetings and discussions. During the current reporting period, the SweetARMOR website has been created as a platform for dissemination of project results. NCSU - (Jennings) Herbicide screening results have been presented to colleagues and IR-4 National Headquarters at the National IR-4 Project meeting in Minnesota in September 2022. LSU - (Watson) SweetARMOR project was highlighted during: The Phytosanitary Workshop at the Society of Nematologists conference in Anchorage, Alaska (September 28, 2022) LSU AgCenter Sweetpotato Field Day in Chase, Louisiana (August 18, 2022) Lamb Weston Meeting Meeting in Delhi, Louisiana (March 29, 2022) A poster was presented by David Galo at the national sweetpotato collaborators Group meeting. A 3-minute thesis presentation and abstract was presented by David Galo at the Society of Nematologists conference in Anchorage, Alaska. See also Other Products. What do you plan to do during the next reporting period to accomplish the goals?Project Timeline Activities Y1 Y 2 Y 3 Y 4 Site (Institution)/ Personnel Obj. 1: Development of holistic sweetpotato crop management solutions for Me. and Mi. 1.1. Evaluate the impact of poor- and non-host rotational cash and cover crops in suppressing Me and Mi within sweetpotato production systems X X X X NC (AG, KJ, JS) 1.2. Evaluate the impact of weed management on field populations of Me and Mi X X X X NC (KJ, JS, AG) 1.3. Explore integration of chemical nematode management with weed management and cultural control methods including rotational crops, and cover crops X X NC (KJ, AG, JS) Obj. 2: Accelerate breeding for Me and Mi resistance by deploying MAS and GS 2.1. Screen and phenotype germplasm to characterize the nature of resistance to Me and Mi X X NC (CY, AG); LA (DL, CC); SC (WR) 2.2 Examine root penetration, nematode development, and histology of infection sites X X X LA (TW) 2.3 Examine sweetpotato root architecture in response to nematode parasitism X X X LA (AV, TW); SC (WR) 2.4. Genome Wide Association Studies (GWAS) for resistance to Mi and Me X X X X SC (PW, WR) 2.5. RNAseq studies to characterize resistance to Me and Mi X X X X LA (NB, DL); SC (WR) Objective 3. Deployment of conventional, marker-assisted and/or genomic selection to develop new market ready varieties with resistance to Me and Mi. 3.1. Conventional breeding and germplasm enhancement for Me and Mi resistance X X X X NC (CY, AG. JS) LA (DL) 3.2. Implementation of GS in sweetpotato X X X X NC (CY, AG); TN (BO) 3.3. Capacity building and access to resources X X X NC (CY); LA (DL, NB); TN (BO); USVL (PW); MS (LH) Obj. 4: Develop high-throughput 2D and 3D storage root phenotyping technologies for the examination of nematode infection and storage root yield and quality 4.1.1 Collect and process biospeckle imagery of roots in agar X X NC (MK, CY, AG) 4.2.1 Capture storage root images X X X X NC (MK, CY, JS, KP, MK, AG); SC (PW) 4.2.2 Measure field materials (biospeckle, polarization, Exeter, PlantEye) X X X NC (MK, CY, AG); SC (PW) 4.2.3 Develop algorithms, process, and assess nematode damage X X X X NC (MK, CY, AG); SC (PW) 4.3.1 Configure & calibrate storage measurement cameras X X NC (MK, CY, AG); SC(PW) 4.3.2 Assess materials in simulated storage environment X X NC (MK, CY, AG) SC (PW) Obj. 5: Economic cost-benefit analyses and effective communication of research results 5.1. Field days, production meetings, and development of a centralized sweetpotato website for engaging with stakeholders X X X X NC (AG, JS, KJ, DT, CY); LA (TW, TS); MS (MS); CA (SS) 5.1.1. Project information and events X X X NC (AG, KJ, JS, DT) 5.1.2. National Sweetpotato Collaborators Group information X X X NC (AG, JS, KJ, DT, CY); LA (TW, TS), MS (MS); CA (SS) 5.1.3. Diagnostic resource X X X X NC (AG, JS, KJ, CY); LA (TW, TS), MS (MS); CA (SS) 5.1.4. Connectivity with stakeholders X X X NC (AG, JS, KJ, CY); LA (TW, TS), MS (MS); CA (SS) 5.1.5. Present progress, economic findings, and recommendations to growers, processors, food manufacturers, and other stakeholders through diverse platforms X X X X NC (AG, JS, KJ, CY); LA (TW, TS); MS (MS); CA (SS) 5.2: Economic Analyses NC (DT) 5.2.1. Partial budgeting analysis for promising varieties and control strategies X X X NC (DT) 5.2.2. Choice modeling and willingness to pay surveys X X X X NC (DT) ? Notes:PI's:AG: Adrienne Gorny; AV: Arthur Villordon; BO: Bode Olukolu; CC: Chris Clark; CY: Craig Yencho; DT: Daniel Tregeagle; DL: Don Labonte; KJ: Katie Jennings; JS: Jonathan Schultheis; LH: Lorin Harvey; MS: Mark Shankle; MK: Michael Kudenov; NB: Niranjan Baisakh; PW: Phillip Wadl; SS: Scott Stoddard; TS: Tara Smith; TW: Tristan Watson; WR: Will Rutter Sites:CA: California; LA: Louisiana; NC: MS: Mississippi; North Carolina; SC: South Carolina; TN: Tennessee Abbreviations:GS: Genomic Selection; MAS: Marker-Assisted Selection
Impacts
What was accomplished under these goals?
Significant advances were accomplished for most of our 5 goals in YR1. Using the SweetARMOR logic model as a guide, a summary of our YR1 achievements is as follows. The SweetARMOR team established a project advisory group, and we convened monthly project member and quarterly advisory group meetings. We also built a project website, and began posting news updates on this site, as well as making presentations about the SweetARMOR project via field days at grower and scientific meetings. Our Meloidogyne enterolobii (Me) and M. incognita (Mi) root knot nematode (RKN) and cultural management teams have begun to design systems-based farm and cultural management tools for RKN control by evaluating the impact of poor- and non-host rotational crops in suppressing RKN. Our weed scientists have also begun to assess the importance of weed management on field populations of RKN. All these efforts are focused on implementing systems-based RKN, weed and cultural control methods as soon as possible in grower's fields. With the ongoing cultural management and weed control efforts, our breeding and bioinformatics teams have begun to conduct greenhouse and field experiments to identify Me/Mi resistant genotypes. These experiments have been very successful, and we have identified several RKN resistant clones to use in our breeding programs. At NCSU, we expect to start screening of early generation breeding materials for Me and Mi resistance using DNA-based KASP markers. If these makers can identify materials with resistance to Me and Mi before we evaluate them in the field this will represent the first use of molecular markers for breeding in sweetpotato. Our Me and Mi phenotyping teams have also begun to develop storage root phenotyping technologies for the examination of nematode infection, root yield and quality, which is a key bottleneck for many aspects of our research. Our extension communication and economics outreach teams have also made significant progress. Most of the SweetARMOR PI's have presented research results at scientific, grower and industry stakeholder meetings. Many of these talks have been presented as invited guests, an indication that our stakeholders value the work that we are conducting and are eager to gain new information on how to control RKN's in their fields and facilities. Last, initial work on the development of an RKN economic survey was conducted in YR1. To do this, our economics team collected relevant literature from existing studies surveying economic cost-benefit analyses of specialty crop growers, creating a foundation for development of a survey instrument that we expect to deploy in YR2. Select YR1 accomplishments by Goal include the following. Goal 1 - Identification of integrated RKN management strategies for use in sweetpotato crop systems. Obj. 1.1. Evaluate the impact of poor- and non-host rotational cash and cover crops in suppressing Me and Mi within sweetpotato production systems (NCSU - Gorny, Schultheis). A replicated field trial for investigating rotational crops and cover crops for management of Me was established during YR1 in collaboration with a grower. Rotational crops (soybean, corn, peanut, and tobacco) were planted in spring 2022 in strip plots. Cover crops (oats, wheat, and a fallow control) will be planted in Fall 2022. Soil samples will be collected in Fall 2022, Spring 2023, and Fall 2023 and will provide RKN count data under each rotational crop by cover crop combination. Obj. 1.2. Evaluate the impact of weed management on field populations of Me and Mi (NCSU - Jennings, Gorny). Weed samples (6 of each spp. present in the field) and soil samples were collected from 3 commercial fields to determine the presence of Me and Mi. Goal 2 - Genomic and phenomic studies focused on introducing RKN resistance into adapted sweetpotato germplasm. Obj. 2.1. Screen and phenotype germplasm to characterize resistance to RKN. LSU - Twenty-two LSU AgCenter breeding lines from 2021 were screened for Me and Mi resistance. Of these, 8 were highly resistant to Me. NCSU - 52 NCSU lines were screened for Me and Mi resistance. Of these, 28 represented the top breeding value progeny of the NCSU genomic selection training population, and the remaining as elite table-stock breeding lines and GS parents. Of these, 10 were resistant to Me and 38 were resistant to Mi based on reproductive factor. An additional 87 genotypes are under evaluation. Obj. 2.3. Examine sweetpotato root architecture in response to nematode parasitism (LSU - Villordon, Watson). Two greenhouse experiments were performed in 2022 to examine the impact of RKN parasitism on root architecture traits on 5 sweetpotato clones: Beauregard (Me and Mi susceptible), Jewel (Me and Mi resistant), L14-31 (Me and Mi resistant), 19-65 (Me resistant and Mi susceptible), and 18-100 (Me susceptible and Mi resistant). Data analysis is underway. Goal 3 - Genomic-assisted breeding of new market-acceptable, RKN-resistant varieties. Obj. 3.1. Conventional breeding and germplasm enhancement for Me and Mi resistance. NCSU - A paired-cross crossing block was established during winter 2022 using clones with Me and Mi resistance acquired from USDA, LSU, and Africa. Selections from the GS training population, as well as elite genotypes testing resistant in bioassay and by KASP genotyping, were also included in the crossing block. Of the 28,518 botanical seed planted, 7,764 were from polycross nurseries focused on Me resistance, and 6,594 for Mi resistance. From our paired-cross nurseries, we planted 3,771 seedlings in which one of the parents possessed Me resistance, while 6,281 were focused on Mi resistance, with many of the Me seedlings potentially with resistance to both Me and Mi. Overall, of the 28,518 seedlings evaluated during 2022, 24,410 (85%) were focused on either Me, Mi or both RKN resistances. USVL - The USVL team is currently harvesting seed from two polycross nurseries that include clones with Me and Mi resistance along with insect resistance. LSU - Lines from LSU newly identified as resistant to Me and Mi in 2022 and ones previously found resistant are being combined in an open-pollinated nursery. Seed and resulting selections will be screened for economic utility in 2023. An open pollinated nursery with resistant parents generated 3000 seeds in 2021. This seedling population is now in 5 plant plots for selection this fall for economic utility. Obj. 3.2. Exploration of GS in sweetpotato. (NCSU - Yencho; UTIA- Olukolu; USVL - Wadl). NCSU GRKN population: Library preparation, SNP calling, and SNP filtering are now complete, but a significant number of samples have low read depth. Following troubleshooting, we found the digestion of DNA samples was not optimal. The library preparation will be repeated following the troubleshooting and optimization to ensure uniform coverage across samples. Obj 4. Develop high throughput 2D and 3D storage root phenotyping technologies for the examination of nematode infection and storage root yield and quality. Obj. 4.2. Quantify signatures in the field and from field materials. NCSU - A field near Snow Hill, NC was selected for study and treated with 15 nematicide treatments, each replicated 4 times. Planting was on July 12, and harvest is planned for early November. Two sets of field measurements using both Raman and UV spectroscopy are planned. The first set of data was collected on September 22. The second set of data is planned for the end of October (roughly two weeks before harvest). Since nematode quantification will not be done after harvest, the collected data currently do not have labels. Obj 5. Economic cost-benefit analyses and effective communication of research results. Obj 5.2.2. Choice modeling and willingness to pay surveys. Initial work on survey development was conducted in YR1, providing information for development of the YR2 survey instrument.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Kilduff, Alice and Daniel Tregeagle. Willingness-to-Pay for Produce: A Meta-Regression Analysis Comparing the Stated Preferences of Producers and Consumers. Horticulturae, 2022, 8(4), 290. Note: ? Funded by SCRI CucCAP2: Harnessing genomic resources for disease resistance and management in cucurbit crops bringing the tools to the field (2020-51181-32139). Research from this publication will be used in developing the surveys for obj 5.2.2.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2022
Citation:
Fraher, Simon. 2022. Advancing Molecular Tools for the Accelerated Release of Root-Knot Nematode Resistant Sweetpotato Varieties. M.S. Thesis, NC State University. 118pp. https://www.lib.ncsu.edu/resolver/1840.20/39564.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Fraher S, Schwarz T, Oloka B, Pecota KV, Heim C, Hamilton J, Da Silva Pereira G, Gorny A, Buell RC, Yencho GC. 2022. Advancing molecular tools for the accelerated release of root-knot nematode resistant sweetpotato varieties (abstr). Presented at the National Sweetpotato Collaborators Group Annual Meeting/SE Region ASHS Annual Meeting, New Orleans, LA. Feb. 11-13, 2022. HortScience 57(9):S278.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Galo D Rezende JS, Clark CA, Labonte DR and Watson T. 2022. Sweetpotato breeding line resistance to Meloidogyne enterolobii and M. incognita (abstr). Presented at the National Sweetpotato Collaborators Group Annual Meeting/SE Region ASHS Annual Meeting, New Orleans, LA. Feb. 11-13, 2022. HortScience 57(9):S278.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Watson, T. 2022. Overview of the SweetARMOR Project. Presented at the Phytosanitary Workshop at the 61st Annual Meeting of the Society of Nematologists. Anchorage, Alaska. September 28, 2022.
- Type:
Websites
Status:
Published
Year Published:
2022
Citation:
Project Website established: https://sweetarmor.org/
A Twitter account for outreach and stakeholder engagement was also created (@SweetARMOR_Team).
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