Skip to main content
ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #405717
Research Project: Genetic Resource and Information Management for Pulse, Temperate Forage Legume, Oilseed, Vegetable, Grasses, Sugar, Ornamental, and Other Crops

Location: Plant Germplasm Introduction and Testing Research

Title: Genetic diversity, population structure and taxonomic confirmation in annual medic (Medicago spp.) collections from Crimea, Ukraine

Author
item Irish, Brian
item Greene, Stephanie
item ZHAO, DONYANG - Breeding Insight
item LIN, MENG - Breeding Insight
item BEIL, CRAIG - Breeding Insight
item SAPKOTA, MANOJ - Breeding Insight
item SHEEHAN, MOIRA - Breeding Insight

Submitted to: Crop Science
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: An annual medic (Medicago spp.) germplasm collection was assembled from the Crimean Peninsula of Ukraine in 2008 to fill gaps in geographic coverage in the USDA ARS NPGS forage legume collections. A total of 102 accessions across 9 Medicago species were collected. To assess genetic diversity, population structure and to confirm taxonomic identities, the collections were phenotypically and genetically characterized. Phenotyping included the use of 25 descriptor traits while genetic characterization was accomplished using a 3K SNP panel developed for alfalfa (Medicago sativa L.) on a Diversity Array Technologies (DArTag) platform. For both field and molecular characterizations, a refence set of 90 corresponding and geographically diverse and representative accessions were also included. Phenotypic descriptors showed consistency among replicate plants within accessions, some variation across accessions within species, and evident distinctions between species. Because the DArTag panel was developed in alfalfa, the transferability of markers to species being evaluated was limited, resulting in an average of ~1500 marker loci detected per species. From these loci, 448 markers present in 95% of the samples were selected for diversity assessment. Principal component and phylogenetic analysis based on the selected markers grouped accessions within same species together and predicted evolutionary relationships among species. Additionally, the markers aided in taxonomic identity of few accessions that were likely mislabeled. The genotyping results also showed that sampling individual plants for these mostly self-pollinating species is sufficient due to high reproducibility between single (n=3 biological) and pooled (n=7 plants) leaf samples. The phenotyping and the 448 SNP marker set were useful in estimating population structure in the Crimean and reference accessions, highlighting the novel and unique genetic diversity in the Crimean collection. Furthermore, this research showed that the SNP markers could be used in a similar fashion to evaluate other plant genetic resource collections of related Medicago.