Revision of Passiflora Subgenus Decaloba ... - Passion Flowers

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above (P. itzensis, P. xiikzodz, P. mcvaughiana, P. juliana, and P. viridiflora) plus
P. megacoriacea, P. sexocellata, P. coriacea, and P. tacana. Passiflora
coriacea, P. sexocellata, and P. tenuiloba form a clade in the molecular analysis.
In the morphological analysis, P. tenuiloba is most closely related to P. pallida, a
species that also occurs in southwestern Texas and northeastern México. In the
molecular analysis, P. coriacea is sister to P. sexocellata and they form a
monophyletic group. In the morphological analysis P. coriacea is also sister to P.
sexocellata, but they are in a clade with P. mcvaughiana, P. xiikzodz, and P.
itzensis. Based upon the molecular data, Passiflora lancifolia is sister to P.
suberosa ssp. suberosa but is more closely related to P. macfadyenii, P. pallida,
and P. suberosa ssp. litoralis in the morphological analysis. In the molecular
analysis P. pallida is sister to all of the members of the supersection, whereas P.
suberosa ssp. suberosa is positioned as sister to the other taxa in the
morphological analysis (see figs. 4.1-4.4 and 6.1-6.2).
Clearly, additional molecular data from more variable gene regions are needed
to help resolve phylogenetic relationships in Passiflora supersection Cieca.
Several gene regions were sequenced in an attempt to attain independent sets of
molecular information, but none proved variable enough to resolve the phylogeny
(trnL-trnF, cytosolic-expressed glutamine synthetase, G3pdh, psbA-trnH). The
only region that proved promising was waxy (granule-bound starch synthase),
but up to seven copies of the gene are found within diploid individuals from the
supersection and my preliminary results could not be interpreted without
extensive and additional sampling (see Appendix).