Submitted to: Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/11/2003
Publication Date: 11/1/2003
Citation: Ashley, M.V., Styan, S.M., Craft, K.J., Jones, K.L., Fessler, J.L., Lewers, K.S., Ashman, T.L. 2003. High variablity and disomic segreation of microsatellites in the octoploid fragaria virginiana (rosaceae). Theoretical and Applied Genetics. 107:1201-1207. Interpretive Summary: Wild relatives and ancestors of cultivated crops are valued as sources of important traits in plant breeding programs. It is important to ensure that wild relatives are available to plant breeders and other scientists and are well characterized. Characterization of wild relatives is hampered by the lack of funding for developing genetic tools, like molecular markers, that have been important in characterization of cultivated crop varieties. Four molecular markers developed from cultivated strawberry and four molecular markers developed from a wild strawberry species were tested on a second wild strawberry species and on cultivated strawberry. Molecular markers from both wild and cultivated strawberry were found useful for characterizing populations and individuals in a wild ancestral strawberry species native to the eastern United States. This finding demonstrates that genetic tools developed for agricultural crop species also can be used by botanists and ecologists to study wild relatives of those crop species, and that the impact of agricultural research extends beyond agriculture to other fields of science.
Technical Abstract: The objectives of the present study were to develop microsatellite markers for the wild strawberry, Fragaria virginiana, to evaluate segregation patterns of microsatellite alleles in this octoploid species, and assess genetic variability at microsatellite loci. A genomic library was screened for microsatellite repeats and several PCR primers were designed and tested; we investigated four microsatellite loci in detail. Segregation patterns in parents and progeny of two controlled crosses at these loci were consistent with disomic Mendelian inheritance. This suggests that the genome of F. virginiana is "highly diplodized" and at least a subset of microsatellite loci can be treated as codominant, diploid markers. A survey of 110 individuals from a population of F. virginiana in Pennsylvania demonstrated high heterozygosities (He or gene diversity ranged from 0.76 to 0.92 per locus) and allelic diversity (12-20 alleles per locus). Significant heterozygote deficiencies were found at three of the four F. virginiana loci for hermaphroditic individuals but at only one locus for females in this gynodioecious species. Finally, we tested the use of heterologous primers and found that F. virginiana primers amplified products in cultivated strawberry, Fragaria x ananassa Duch. and F. chiloensis. Microsatellite loci developed from cultivated strawberry successfully amplified F. virginiana loci.