Evaluation location: Oregon, United States
The United States Department of Agriculture (USDA) - Agricultural Research Service (ARS) - National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, is a genebank that preserves strawberry genetic resources. In 2004, two Asian diploid species, F. iinumae Makino and F. nipponica Makino were collected during an expedition in Hokkaido, Japan. F. iinumae, or its ancestor, may be a progenitor of the `B? genome for the cultivated octoploid strawberry, F. ? ananassa Duschesne. The objective of this study was to evaluate the diversity of these two species? populations using simple sequence repeat (SSR) markers. Twenty of 82 Fragaria derived SSRs, polymorphic among and within the two species were selected for the genetic analysis of 137 Hokkaido accessions. A significant difference in the genetic diversity between the two species was observed; F. nipponica (0.4542) and F. iinumae (0.1808). Three possible interspecific hybrids were identified from their intermediate memberships in the two diploid species groups. Further clustering within the species groups resulted in seven subclusters in F. iinumae and three in F. nipponica that may represent historical lineages useful for long term preservation of the two species. An octoploid accession was identified from SSR analysis and its ploidy confirmed by flow cytometry. The results of this study were published in Genetic Resources and Crop Evolution and is available online at http://www.springerlink.com/content/c404m461448gp6r3/fulltext.html