Resolving identity of blueberry cultivars with a microsatellite fingerprinting set

Authors: YALCIN, OZGECAN - Oregon State University; Green, Jaimie; Nyberg, April; Hummer, Kim; Hardigan, Michael; LUBY, CLAIRE - University Of Wisconsin; Bassil, Nahla

Submitted to: Hortscience Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2021
Publication Date: 9/1/2021
Citation: Yalcin, O., Green, J., Nyberg, A.M., Hummer, K.E., Hardigan, M.A., Luby, C., Bassil, N.V. 2021. Resolving identity of blueberry cultivars with a microsatellite fingerprinting set. Abstract for the American Society for Horticultural Science Meeting in August 5-9, 2021, virtual meeting.

Interpretive Summary: The United States Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (USDA, ARS, NCGR) in Corvallis, Oregon, conserves a collection of more than 1,800 blueberry accessions from 34 countries. Confirming the identity of blueberry cultivars preserved at the NCGR is crucial for efficient genebank management. Previously, a DNA test was developed in blueberry and used along with parentage analysis to confirm identity in 297 plants representing 143 unique accessions from this genebank. The objective of this study was to resolve the identity of these accessions, and establish baseline fingerprints for the remaining cultivated blueberries (46) in the NCGR collection. We genotyped 129 samples representing 91 unique accessions with this DNA test. In addition to the true-to-type (TTT) accessions identified by this method, we detected a number of plants that needed additional study to confirm them as TTT. Plants for each of the accessions were obtained from two to five sources such as breeder collections and private nurseries. Parentage analysis using as many TTT parents or offspring as possible will resolve the identities of these cultivars, and will be presented. This study will provide a protocol to ensure clonal identity of the NCGR blueberry collection.

Technical Abstract: The United States Department of Agriculture Agricultural Research Service National Clonal Germplasm Repository (USDA-ARS NCGR) in Corvallis, Oregon conserves a collection of more than 1,800 Vaccinium L. accessions represented by 83 Vaccinium taxa from 34 countries. Confirming the genotypic identity of blueberry cultivars preserved at the NCGR is crucial for efficient genebank management. Microsatellite, or simple sequence repeat markers (SSRs), have been used in this endeavor. Previously, a 10-SSR fingerprinting set of tri-nucleotide-containing-SSRs in blueberry was developed and used along with parentage analysis to confirm identity in 297 plants representing 143 unique accessions from the NCGR collection. Four categories of plants were subsequently identified: true-to-type (TTT) where morphology, SSR markers, and parentage analysis agreed; identity ok (IDOK) where a unique genotype was generated in multiple plants from different sources but parentage analysis was incomplete; identity question (IDQ) where allele composition did not match parentage and more testing is needed to confirm identity; and identity wrong (IDX) where incorrect identity is confirmed by parentage analysis and replacement with TTT is required. The objective of this study was to resolve the identity of accessions in the IDOK (7) and IDQ (13) categories, replace accessions in the IDX (2) category with TTT genotypes, and establish baseline fingerprints for the remaining cultivated blueberries (46) in the NCGR collection. We genotyped 129 samples representing 91 unique accessions with the 10-SSR set. Plants for each of the accessions in the IDOK, IDQ, and IDX categories were obtained from two to five sources such as breeder collections and private nurseries. Parentage analysis using as many TTT parents or offspring as possible will resolve the identities of these cultivars, and will be presented. This study will provide a protocol to ensure clonal identity of the NCGR blueberry collection.