R. Samuel et al., PHYLOGENY OF SOME SPECIES OF CYRTANDRA (CESNERIACEAE) INFERRED FROM THE ATPB RBCL CPDNA INTERGENE REGION/, Botanica acta, 110(6), 1997, pp. 503-510
The PCR-amplified atpB/rbcL spacer region of ten Cyrtandra species and
representatives of the genera Didymocarpus, Didissandra, and Monophyl
laea was sequenced and used for phylogenetic analyses. In Cyrtandra 83
variable positions were found over a length of 890bp. The data sugges
t that the Samoan species included in our study originated by at least
two independent colonization events, while for the Hawaiian species t
he situation is not clear yet. With respect to generic relationships,
Monophyllaea shows considerable divergence (9.9%) from the remaining t
axa and thus is used as outgroup. Didymocarpus is most closely related
to Cyrtandra, their genetic divergence (2.2%) being only slightly hig
her than the average distance within Cyrtandra (1.9%). The promoter re
gions for the atpB and rbcL genes, which have been described from Rubi
aceae, were identified and found to be located at homologous positions
. Of the two atpB promoters found in Rubiaceae only the distal one app
ears functional, the proximal promoter has been eroded by mutations an
d is disrupted in Didissandra by a 14bp insertion.