USDA-ARS Alfalfa Plant Genetic Resources, Population Genetics and Breeding Postdoc

This is a USDA ARS position and is offered through the ORISE educational opportunity system of the Oak Ridge National Laboratories and is based in Prosser, Washington. Please note, ORISE will pay a stipend that will include funding for all health and associated insurance; benefits are not offered in addition to the annual stipend.

Research Project:
Alfalfa is the world’s most important forage legume crop, and its plant genetic resource (PGR) collections contain important genetic diversity for crop improvement. Systematic and thorough genotypic and phenotypic characterization would improve collection utility and aid in genomewide association studies (GWAS) and genomic selection (GS). Useful diversity could be made more accessible to breeders via pre-breeding activities creating publicly available improved germplasm.

Objective:
Apply high-throughput genomics and phenomics tools to characterize the USDA ARS National Plant Germplasm System (NPGS) alfalfa collections and previously improved germplasm. Analyses of data may include handling, filtering, and calculations of genetic diversity, relationships, and GWAS/GS. Information is expected to be uploaded into public databases to ensure all data become publicly available. Project intends to create or advance crosses between accessions containing useful traits via phenotypic or genetic/GS.

Approach:
During this educational appointment, you will collaborate in research closely with PGITRU unit members, especially the Temperate-adapted Forage Legume program. You will liaise with other established USDA ARS collaborators including Breeding Insight and alfalfa research collaborators in CA, MN, WA, and WI while conducting research. The alfalfa collections and improved germplasm will be characterized in greenhouse or field plantings in Prosser, Washington.

Genotyping activities will be outsourced, and data receipt and initial quality assessment will be coordinated with the genotyping service institution and collaborators. You will receive sequence/genotype data, conduct analyses to survey variation, calculate relationships, and other relevant analyses of genebank accessions and improved germplasm. You will interact with collaborators to upload genotypic and phenotypic data directly into the GRIN-Global database or to link data generated via an external public platform for access.

Population level crosses will be initiated, or existing crossed families will be grown, phenotyped or genotyped, and selections made to advance to the next generation. The program has office, laboratory, greenhouse, field space, equipment, and supplies for planned experiments. Staff, collaborators, and lead scientists will support you in technical aspects of project.

Expected Results:
New genetic and phenotypic characterization of the alfalfa genetic resources and/or improved germplasm will improve collection management and promote their efficient use, for traits including but not limited to forage quality and disease resistance. Results may include:

• Estimating genetic diversity and population structure among and between all accessions in the collection,
• Correct accession taxonomic assignments,
• Redundancy identification leading to increased efficiency,
• Gaps in coverage revealed leading to targets for acquisition, and;
• Aptly characterized PGR accessions in collections that can be used to identify subsets of variation for in-house and stakeholder mining of beneficial alleles in pre-breeding.

Results will allow US breeders to create new varieties with higher forage quality, require fewer chemical or irrigation inputs, and be more resistant to new insect, disease, or environmental threats, thus increasing farmer profits. With fully characterized alfalfa, breeders and geneticists can request the best accessions or incorporate improved germplasm for their research programs, including expanded marker trait associations via GWAS and breeding of new cultivars for all traits of interest.

Characterization of the alfalfa can aid in effective management of the germplasm collection while improving and promoting the use of improved germplasm by stakeholders.

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