SPECIES IDENTIFICATION AND DIVERSITY IN FRAGARIA L. USING NUCLEAR REGIONS AND UNIVERSAL CHLOROPLAST SSRS
The US National Fragaria collection at the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Clonal Germplasm Repository (NCGR) is dynamic through the discovery and collection of new acquisitions and new characteristics that delineate existing species. Previous research using standard Fragaria chloroplast genome regions exhibited limited variation and was unsuccessful at distinguishing between species. The objective of this study was to examine universal chloroplast simple sequence repeats SSRs (cpSSRs) to evaluate diversity in Fragaria species. Four universal cpSSRs (ccmp2, ccmp5, ccmp6, and ccmp7) generated 28 Fragaria haplotypes in ninety four accessions representing 20 Fragaria taxa. Taxa-specific haplotypes were identified for F. nipponica, F. orientalis, F. iinumae and F. nilgerrensis. An octoploid-specific haplotype was observed in cultivated F. ×ananassa, F. chiloensis and F. virginiana supporting their close relationship. Genetic diversity using only four universal SSR markers was moderate (0.54, on average) despite the observed homoplasy. Species-specific dehydroascorbate reductase (DHAR) and granule-bound starch synthase (GBSSI-2) gene sequences were also evaluated to identify diploid strawberry species. Marker results and future needs for additional Fragaria-specific primers that may more accurately identify the chloroplast diversity in Fragaria will be discussed.
Njuguna, W., Denoyes, B., Horvath, A., Hummer, K.E. and Bassil, N.V. (2014). SPECIES IDENTIFICATION AND DIVERSITY IN FRAGARIA L. USING NUCLEAR REGIONS AND UNIVERSAL CHLOROPLAST SSRS. Acta Hortic. 1049, 335-342
universal chloroplast markers, DHAR, Fragaria, strawberry, haplotypes