Conclusions: Among diploid Fragaria species, a general consistency of rDNA site numbers implies conserved
genomic organization, but highly variable 25S signal sizes and intensities and two instances of site loss suggest
concurrent high dynamics of rDNA copy numbers among both homologs and non-homologs. General
conservation of rDNA site numbers in lower ploidy, but marked site number reductions at higher ploidy levels,
suggest complex evolution of rDNA sites during polyploidization and/or independent evolutionary pathways for 6x
versus higher ploidy strawberries. Site number comparisons suggest common genomic composition among natural
octoploids, and independent origins of the two divergent decaploid accessions.