Progress on the molecular characterization of the USDA National Pear Collection

Authors: Bassil, Nahla; King, Ryan; Nyberg, April; ZURN, JASON - Former ARS Employee; Clare, Shaun; Reinhold Aboosaie, Lauri; POSTMAN, JOSEPH - Former ARS Employee; GILMORE, BARBARA - Former ARS Employee; Flores, Gabriel; Volk, Gayle; Jenderek, Maria; MONTANARI, SARA - New Zealand Institute Of Plant & Food Research; CHAGNE, DAVID - New Zealand Institute Of Plant & Food Research; BUS, VINCENT - New Zealand Institute Of Plant & Food Research; BREWER, LESTER - New Zealand Institute Of Plant & Food Research; Dardick, Christopher - Chris; Gottschalk, Christopher; DUREL, CHARLES-ERIC - Inrae; DENANCE, CAROLINE - Inrae

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2023
Publication Date: 12/7/2023
Citation: Bassil, N.V., King, R., Nyberg, A.M., Zurn, J., Clare, S.J., Reinhold Aboosaie, L.A., Postman, J., Gilmore, B., Flores, G.N., Volk, G.M., Jenderek, M.M., Montanari, S., Chagne, D., Bus, V., Brewer, L., Dardick, C.D., Gottschalk, C.C., Durel, C., Denance, C. 2023. Progress on the molecular characterization of the USDA National Pear Collection. Acta Horticulturae. 1384:273-280. https://doi.org/10.17660/ActaHortic.2023.1384.36.
DOI: https://doi.org/10.17660/ActaHortic.2023.1384.36

Interpretive Summary: The U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) conserves 2,378 accessions of pear and 478 pear wild relatives in an orchard at the National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon. DNA markers are used for efficient management of this collection by identifying and eliminating duplicates and mis-labeled trees, and ensuring a diverse collection of true-to-type heritage cultivars and their wild relatives. A reference genotype database of 497 accessions based on DNA markers has allowed us to identify unknown pear trees in four collections across four U.S. states. Fireblight is a worldwide disease problem and one of our projects focuses on developing diagnostic markers for resistance to this devastating pathogen that can help identify genotypes to use in breeding new cultivars. Future work includes comparing the DNA-based genotypes of important pear cultivars preserved at the NCGR across European collections to obtain a global view of heritage pear genetic resources. We also plan to increase the number of genotypes in this reference database, and confirm DNA-marker-identified duplicates through phenotypic evaluation. Conservation and characterization of pear genetic resources at the NCGR is a global effort.

Technical Abstract: The U.S. Department of Agriculture, Agricultural Research Service maintains 2,378 accessions of pear and 478 wild pear relatives in an orchard at the National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon. A simple sequence repeat (SSR)-based fingerprinting set of 10 SSRs and an array of 70,000 single nucleotide polymorphism (SNP) markers are used for efficient management of this collection by identifying and eliminating duplicates and mis-labeled trees, and ensuring a diverse collection of true-to-type heritage cultivars and their wild relatives. A reference genotype database of 497 accessions based on SSR markers has allowed us to identify unknown pear trees in four collections across four U.S. states. Fireblight is a worldwide disease problem and one of our projects focuses on developing diagnostic markers for resistance to this devastating pathogen that can help identify genotypes to use in breeding new cultivars. Future work includes comparing the SSR-based genotypes of important pear cultivars preserved at the NCGR across European collections to obtain a global view of heritage pear genetic resources, increasing the number of genotypes in the SSR-based reference database, and confirming SNP-determined duplicates through phenotypic evaluation. Conservation and characterization of pear genetic resources at the NCGR is a global effort.