| Abstract Detail
Systematics Section / ASPT Murfett, Jane [1], Lee, Chris [1], Page, Larry [1], Yates, Allena [1], Ippolito, Anthony [2], Holtsford, Timothy P. [1]. Phylogenetics of Nicotiana Section Alatae and description of N. rastroensis. We studied species relationships in Nicotiana Section Alatae with nrITS sequences, 256 ISSR bands, interspecific crossability, floral morphology and corolla and calyx
development. Nuclear ribosomal internal transcribed spacer (nrITS) DNA sequences supported a
monophyletic Alatae, but one
that does not include N. sylvestris
(Ippolito 2000, Chase et al. 2003, cf. Goodspeed 1954). Within Alatae one clade was resolved
consisting of the n=10 species, N.
longiflora and N.
plumbaginfolia. Ippolito's nrITS tree also suggested a
paraphyletic relationship of N.
plumbaginifoia to N.
longiflora. This was confirmed using 256 ISSR bands in an Alatae-wide parsimony tree and
further resolved in a tree containing 14 populations and 24 individuals
of the n=10 species. We have observed 3 populations in NW
Argentina where N. longiflora
and N. plumbaginifolia are
sympatric and putative hybrids were seen. However, most the of
the intermediate morphs form a highly supported clade suggesting the
medium floral morphs may represent a separate evolution of smaller
flowers. The Alatae-wide
ISSR tree also found a weakly supported clade containing N. bonariensis, as sister to the
rest of the n=9 group.
Crossability interpretations are complicated. Style length was a very
good predictor of interspecific crossing success as measured by seed
set and pollen tube growth rates. This suggests that Biological Species
Concept boundaries could evolve as a pleiotropic result of flower size
evolution, or vice versa. Floral organ dimensions and developmental
trajectories suggest the following pairs of species are most closely
related to each other: N. mutabilis
and N. langsdorffiii; N. rastroensis and N. bonariensis; N. alata and N. forgetiana (the last hypothesis
is also suggested by biogeography), but these relationships were not
always supported by crossability. Crossability, morphology,
development of flowers and daily phenology suggest a species be erected
for N. rastroensis.
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1 - University of Missouri-Columbia, Biological Sciences, 105 Tucker Hall, Columbia, Missouri, 65211, USA
2 - De Paul University, Department of Biological Sciences, 111 MacGowan Hall, Chicago, Illinois, 60614, USA
Keywords:
Nicotiana
Solanaceae
systematics.
Presentation Type: Poster
Session: 33-97
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM
Abstract ID:359 |
