Location: Plant Germplasm Introduction and Testing Research
Project Number: 2090-21000-037-011-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2022
End Date: Sep 14, 2024
Objective:
In collaboration with UC Davis, UC Riverside, Delaware Valley University, University of Delaware, Iowa State University, and The National Center for Genome Resources, the following are the objectives of the proposed grant:
1. Genotype the USDA lima bean (Phaseolus lunatus) collection, a lima bean Genome Wide Association Study (GWAS) panel, and five recombinant inbred line (RIL) populations of lima bean using genotyping-by-sequencing (GBS). Integrate this genotyping information into the publicly available Legume Information System (LIS) website.
2. Develop molecular markers for photoperiod insensitivity, bush growth habit, and white seed color for a backcross marker conversion program for these traits.
3. Develop high throughput phenotyping via unmanned aerial vehicles and robots.
4. Evaluate a day neutral diversity panel of genotyped lima beans for protein and fiber content for GWAS. Evaluate five RIL populations for protein, total dietary fiber, total phenolics, cyanogenic glucoside, biotic stresses (lygus and nematodes), day length sensitivity, plant habit, and seed color. Integrate phenotypic information into LIS.
5. Research and results will be publicized through reports, meetings, field days, and web sites.
Approach:
ARS will lead establishment and continued engagement of outside stakeholder Advisory Committee (OAC) 2022-2026, and organize field demonstrations at MidAtlantic farm locations summer 2023-2025. Field demonstrations will work as both outreach and to inform decisions on parents for future regional breeding efforts.
ARS will perform crosses of lines, which perform well in consumer and field evaluations, informed by results from Delaware Valley University taste panels and field data. The target geographic region would be the MidAtlantic, with focus on short season, direct market, dry bean, bush types. 5 prebreeding lines
will be developed and shared with MidAtlantic growers, seedsmen, and master gardeners.
At the beginning of year one of the grant before planting, ARS will provide over 700 NPGS lima bean accessions for research. Seeds from the said accessions will be shipped to UC Davis for genotyping.
The first year of the grant will be dedicated to regenerating up to 300 day-neutral varieties of lima bean from the NPGS collections that have been genotyped at UC Davis and have gone through one round of single seed descent. The materials will undergo field trials to assess their adaptive fitness in the local climate and soil, their day-neutral status, and their disease status vis-à-vis bean common mosaic virus (BCMV). The first year of field trials will cull the population down to those lines that are most fit, are clearly day-neutral, and are free of BCMV symptoms. This fit, robust, and well adapted collection will be increased for field trials in year two.
The GWAS panel will be planted at the USDA Central Ferry Farm, WA during years two and three of the grant. Three randomized blocks will be planted with border rows on the outside edge. Due to the fact that most lima bean accessions in the NPGS collections have a pole growth habit, double spacing will be utilized in the field to accommodate the sprawling vines. Mature, dry seeds will be harvested and measured for protein and total dietary fiber using a near infrared laser instrument. The protein and fiber measurements will be utilized in GWAS mapping for identifying quantitative trait nucleotides.
Phenotypic data from the GWAS panel and from any further NPGS accessions that time permits will be incorporated into the publicly available GRIN-Global database. It is hoped that it will be possible at a future date to incorporate genotypic data into the GRIN-Global database as well, but the modifications of the database necessary for such additions do not yet exist.
