D. Potter et al., Phylogenetic relationships among species of Fragaria (Rosaceae) inferred from non-coding nuclear and chloroplast DNA sequences, SYST BOT, 25(2), 2000, pp. 337-348
Phylogenetic relationships among 43 accessions of Fragaria, representing 14
species, and one accession of the outgroup Potentilla fruticosa, were asse
ssed using nucleotide sequence data from the nuclear ITS region and from a
region of the chloroplast genome including the trnL intron and the trnL-trn
F spacer. Variability was low in both regions and lower in the chloroplast
than in the nuclear sequences. The data were analyzed cladistically, separa
tely and in combination. Greater phylogenetic resolution was obtained with
the ITS and combined data than with the trn data; the strict consensus tree
from the combined data analysis was very similar to that from the ITS anal
ysis, but the position of some accessions was affected by the inclusion of
the trn data. The results support the following conclusions: Fragaria iinum
ae is sister to all other species in the genus; F. vesca and F. nubicola ar
e the diploid species most closely related to the polyploid species, includ
ing the tetraploid F. orientalis, the hexaploid F. moschata, and the octopl
oids F. chiloensis and F. virginiana; the latter two species are sister tax
a; accessions of F. virginiana subsp, platypetala from Oregon and Nevada ar
e more closely related to F. chiloensis than to other accessions of F. virg
iniana. The data provide support for the identification of some accessions
in the National Clonal Germplasm Repository in Corvallis, Oregon.