ARS | Publication request: SSR Fingerprinting Panel Verifies Identities of Clones in Backup Hazelnut Collection of USDA Genebank

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 20, 2009
Publication Date: October 20, 2009
Citation: Bassil, N.V., Postman, J.D., Hummer, K.E., Sezer, A., Botu, M. 2009. SSR Fingerprinting Panel Verifies Identities of Clones in Backup Hazelnut Collection of USDA Genebank. Acta Horticulturae. 845:95-102.

Interpretive Summary: The US Department of Agriculture (USDA), Agricultural Research Service maintains a genebank representing world hazelnut diversity. More than 670 clones are preserved as self-rooted trees in a two-hectare field planting in Corvallis, Oregon, with a single tree per accession. In 1996 and 1997, prior to the spread of eastern filbert blight to within 75 kilometers of Corvallis, a backup collection was established in Parlier, California. A core collection of 184 genotypes representing the wide taxonomic, geographic and phenotypic diversity of hazelnut was targeted for this second planting. Two trees of each ‘core’ genotype were grafted onto seedling rootstocks over a period of five years and an orchard was established in Parlier. The grafted trees in Parlier are at risk of identity problems due to suckers arising from below the graft union. In May 2007, young leaves were collected from 29 Parlier trees that exhibited uncharacteristic morphological phenotypes. A set of 12 DNA-based simple sequence repeat (SSR) markers was used to fingerprint trees in the backup collection, and the results were compared to the fingerprints of the same accessions in the Corvallis collection. Based on the results, three misidentified accessions were eliminated and recommendations were made for refining the fingerprinting set for future use.

Technical Abstract: The US Department of Agriculture (USDA), Agricultural Research Service maintains a genebank representing world hazelnut (Corylus L.) diversity. More than 670 clones are preserved as self-rooted trees in a two-hectare field planting in Corvallis, Oregon, with a single tree per accession. In 1996 and 1997, prior to the spread of eastern filbert blight caused by Anisogramma anomala to within 75 kilometers of Corvallis, a backup collection was established in Parlier, California. A core collection of 184 genotypes representing the wide taxonomic, geographic and phenotypic diversity of Corylus was targeted for this second planting. Two trees of each ‘core’ genotype were grafted onto seedling rootstocks over a period of five years and an orchard was established in Parlier. The grafted trees in Parlier are at risk of identity problems due to suckers arising from below the graft union. In May 2007, young leaves were collected from 29 Parlier trees that exhibited uncharacteristic morphological phenotypes. A set of 12 simple sequence repeat (SSR) markers was used to fingerprint trees in the backup collection, and the results were compared to the fingerprints of the same accessions in the Corvallis collection. Based on the results, misidentified accessions will be eliminated and the fingerprinting set will be refined further.