Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/22/2006
Publication Date: 7/1/2006
Citation: Davis, T.M., Lewers, K.S., Yang, R., Styan, S.M., Dimeglio, L.M. 2006. Assessment of ssr marker transfer from the cultivated strawberry to diploid strawberry species: frequency of amplification, linkage group assignment, and use in diversity analysis. Journal of the American Society for Horticultural Science. 131(4):506-512. Interpretive Summary: The cultivated strawberry originated as a result of hybridization between two wild strawberry species. These parental species also are thought to have originated from one or more older strawberry species with simpler genomic composition. The simpler genomes of these ancestral species makes them useful as models in predicting trait inheritance and gene expression in the cultivated strawberry, but this is true only if we demonstrate similarity between the ancestral species and the cultivated strawberry. In this study, we used molecular markers designed from cultivated strawberry to determine if they could be used with six putative ancestral strawberry species. The results show that some of the ancestral species were similar enough to cultivated strawberry to use as a model. These findings will be of interest to scientists interested in strawberry evolution, trait inheritance and gene expression.
Technical Abstract: The cultivated strawberry, Fragaria ×ananassa Duchesne ex Rozier, originated via hybridization between octoploids F. chiloensis (L.) Mill. and F. virginiana Mill. These three octoploid species are thought to share a putative genome composition of AAA'A'BBB'B'. Diploid F. vesca L., is considered to have donated the A genome. Current attention to the development of F. vesca as a diploid model species for strawberry genomics lends importance to the thorough assessment of simple sequence repeat (SSR) marker commonality between the octoploid and diploid species in Fragaria. In the present study, 23 SSR primer pairs, derived screening a genomic library of F. ×ananassa ‘Earliglow’, were tested on representatives of six diploid Fragaria species, including eight representatives of F. vesca, four of F. viridis Weston, and one each of F. nubicola (Hook. f.) Lindl. ex Lacaita, F. mandshurica Staudt, nom. inval., F. iinumae Makino, and F. nilgerrensis Schltdl. ex J. Gay. SSR primer pair functionality from F. ×ananassa, as measured by amplification success rate (= 100% – failure rate) in the test species, was ranked (from highest to lowest) as follows: F. vesca (98.4%) > F. iinumae (93.8%) = F. nubicola (93.8%) > F. mandshurica (87.5%) > F. nilgerrensis (75%) > F. viridis (73.4%). The extent to which these octoploid-derived SSR primer pairs generated markers that could be added to the F. vesca linkage map also was assessed. Of the 13 F. ×ananassa SSR markers that segregated codominantly in the F. vesca mapping population, 11 were assigned to linkage groups based upon close linkages to previously mapped loci. These markers were distributed over six of the seven F. vesca linkage groups, and can serve as anchor loci defining these six groups for purposes of comparative mapping between diploid strawberry and cultivated octoploid strawberry.