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Subtribal relationships in tribe Tradescantieae (Commelinaceae) based on molecular and morphological data

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The tribe Tradescantieae (Commelinaceae) consists of seven subtribes and 26 genera. Previous attempts to evaluate phylogenetic relationships within the group using morphology or the chloroplast-encoded rbcL have either been highly homoplasious (morphology) or provided weak support for subtribal relationships due to a low mutation rate (rbcL). In this study, phylogenetic analysis of nucleotide sequence data from the chloroplast-encoded ndhF and rbcL genes, as well as 47 morphological and anatomical characters, were used to evaluate relationships within and among subtribes of Tradescantieae. The analyses suggest the following: 1) subtribes Coleotrypinae, Cyanotinae, and Tradescantiinae (with the addition of Elasis) are monophyletic; 2) subtribe Thyrsantheminae is polyphyletic; and 3) subtribe Dichorisandrinae is polyphyletic. Members of Dichorisandrinae are united into two clades (Dichorisandra and Siderasis; Cochliostema, Geogenanthus, and Plowmanianthus) whose relationships are now resolved. The position of Old World subtribes Cyanotinae and Coleotrypinae, nested within New World taxa suggested by rbcL studies, are supported by the addition of ndhF data.
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2006, by The Rancho Santa Ana Botanic Garden, Claremont, CA 91711-3157
SUBTRIBAL RELATIONSHIPS IN TRIBE TRADESCANTIEAE (COMMELINACEAE) BASED ON MOLECULAR
AND MORPHOLOGICAL DATA
D
YLAN
J. W
ADE
,
1,3
T
IMOTHY
M. E
VANS
,
1,4
AND
R
OBERT
B. F
ADEN
2
1
Department of Biology, Hope College, 35 East 12
th
Street, Holland, Michigan 49423-9000, USA;
2
Department of Botany, MRC 166, National Museum of Natural History, Smithsonian Institution,
PO Box 37012, Washington, D. C. 20013-7012, USA
4
Corresponding author (evanst@webmail.hope.edu)
ABSTRACT
Tribe Tradescantieae (Commelinaceae) consists of seven subtribes and 25 genera. Previous attempts
to evaluate phylogenetic relationships within the group using morphology or the chloroplast-encoded
rbcL have either been highly homoplasious (morphology) or provided only weak support for subtribal
relationships due to insufficient variability (rbcL). In this study, phylogenetic analysis of nucleotide
sequence data from the chloroplast-encoded ndhF and rbcL genes, as well as 47 morphological and
anatomical characters, were used to evaluate relationships within and among the subtribes of Trades-
cantieae. The addition of ndhF resulted in a more highly resolved phylogeny and greater bootstrap
and decay values than were obtained by rbcL alone or rbcL and morphology. The analyses suggest
the following: (1) subtribes Coleotrypinae, Cyanotinae, and Tradescantiinae (with the addition of
Elasis) are monophyletic; (2) subtribe Thyrsantheminae is polyphyletic; and (3) subtribe Dichorisan-
drinae is polyphyletic. Members of Dichorisandrinae are united into two clades (Dichorisandra and
Siderasis; Cochliostema, Geogenanthus, and Plowmanianthus) whose relationships are more clearly
resolved. The position of Old World subtribes Cyanotinae and Coleotrypinae, nested within New World
taxa suggested by rbcL studies, are supported by the addition of ndhF data.
Key words: Commelinaceae, molecular phylogeny, ndhF, rbcL, Tradescantieae.
INTRODUCTION
Tribe Tradescantieae (Meisn.) Faden & D. R. Hunt is the
most diverse group within subfamily Commelinoideae (Fa-
den and Hunt 1991). Meisner (1842) defined the tribe based
on the presence of six fertile stamens. Clarke (1881) used
both staminal characters and fruit type to separate Trades-
cantieae from tribes Commelineae and Pollieae. Woodson
(1942) and Rohweder (1956) each emphasized inflorescence
characters. Brenan (1966) used several characters to divide
the whole family into 15 informal groups and this classifi-
cation was followed until Faden and Hunt (1991). Faden and
Hunt (1991) and Faden (1998) employed a broad array of
morphological and anatomical characters to divide the tribe
into seven subtribes, containing 26 genera and approximate-
ly 285 species.
Circumscription of tribe Tradescantieae has varied greatly
due to high amounts of homoplasy in morphological char-
acters (Evans et al. 2000b). The tribe is naturally split into
Old World and New World components, with Cyanotinae,
Coleotrypinae, Palisotinae, and Streptoliriinae restricted to
the Old World, and Dichorisandrinae, Thyrsantheminae, and
Tradescantiinae to the New World (Faden and Hunt 1991;
Evans et al. 2000a, 2003).
Evans (1995) and Evans et al. (2000a) conducted a cla-
distic analysis of morphological characters in Commelina-
ceae, and the results were largely incongruent with Faden
and Hunt’s classification, presumably due to a high degree
of homoplasy in the data. Evans et al. (2003) provided a
3
Present address: Department of Botany, University of Wyoming,
PO. Box 3165, Laramie, Wyoming 82071, USA.
phylogenetic analysis using the chloroplast-encoded gene
rbcL as well as a combined molecular/morphological data
set. Both molecular and combined analyses produced phy-
logenies that were largely congruent with Faden and Hunt’s
classification and incongruent with the morphological phy-
logeny. The phylogenies are in disagreement with Faden and
Hunt’s classification in that: (1) Palisota Rchb. ex Endl. is
basal to both Tradescantieae and Commelineae (making Tra-
descantieae paraphyletic); (2) Thyrsanthemineae are poly-
phyletic; and (3) the monophyly of Dichorisandrineae is in
question, as it is weakly supported by the combined rbcL/
morphology analysis, but not supported by the rbcL data
alone. Hardy (2001), with a more detailed study of morpho-
logical and molecular characters in Dichorisandrineae pro-
vided support for a monophyletic subtribe. Finally, the DNA
data exhibited less homoplasy than the morphological data.
Relationships among subtribes of Tradescantieae were
only weakly supported in the molecular analysis of Evans et
al. (2003) as evidenced by low bootstrap and decay values.
Thus, there was a need to perform an analysis using another
gene to aid in providing a well-supported phylogeny for
members of Tradescantieae. Givnish and Sytsma (1997)
demonstrated that including a higher number of variable or
informative characters in an analysis increased the chances
of obtaining the correct phylogeny. The chloroplast-encoded
gene ndhF was chosen for this study because: (1) ndhFis
1.5 times longer than rbcL (Olmstead and Palmer 1994; Kim
and Jansen 1995); (2) ndhF has a relatively high substitution
rate (approximately twice that of rbcL) (Olmstead and Palm-
er 1994; Kim and Jansen 1995); and (3) ndhF has been
known to provide informative characters in several families
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Table 1. Taxa included for analysis of rbcL and ndhF in Commelinaceae. *Indicates sequence obtained for this study.
Taxa Source
GenBank accession
number (rbcL)
GenBank accession
number (ndhF)
Amischotolype monosperma (C. B. Clarke)
I. M. Turner
Bogner 1811 AF312239 AY198178
Belosynapsis kewensis Hassk. Horticulture–University of Chicago
greenhouse
AF312257 *AY624111
Callisia Loefl.
Callisia repens (Jacq.) L. Graf s.n. AF312247 *AY624109
Cochliostema Lem.
Cochliostema odoratissimum Lem. ex Marie Selby Botanical Garden s.n. AF312244 *AY624114
Coleotrype natalensis C. B. Clarke Goldblatt 6587 AF312243 *AY624115
Cyanotis repens Faden & D. M. Cameron
subsp. repens ined.
Faden 8/82 AF312241 *AY624116
Dichorisandra J. C. Mikan
Dichorisandra thyrsiflora Mikan Horticulture–Missouri Botanical
Garden s.n.
AF312242 *AY624117
Elasis D. R. Hunt
Elasis hirsuta (Kunth) D. R. Hunt MacDougal & Lalumondier 4953 AF312251 *AY624118
Geogenanthus Ule
Geogenanthus poeppigii (Miq.) Faden Des Moines Botanical Center AF312261 *AY624119
Gibasis geniculata (Jacq.) Rohweder Horticulture–Missouri Botanical
Garden s.n.
AF312250 *AY624127
Palisota Rchb.
Palisota ambigua (P. Beauv.) C. B. Clarke Faden 86/55 AF312240 *AY624120
Plowmanianthus Faden & C. R. Hardy
Plowmanianthus sp. Encarnacio´n et al. 93–542 AF312258 *AY624121
Siderasis Raf.
Siderasis fuscata (Lodd.) H. E. Moore Horticulture–Missouri Botanical
Garden s.n.
AF312254 *AY624128
Spatholirion Ridl.
Spatholirion longifolium Dunn Chase 593 AF036887 AY198179
Tradescantia soconuscana Matuda Faden 76/98 AF312238 *AY624124
Thyrsanthemum Pichon
Thyrsanthemum sp. Chase 606 AF312246 *AY624122
Tinantia Scheidw.
Tinantia leiocalyx C. B. Clarke Iltis 3065 *AY624123
Tripogandra Raf.
Tripogandra diuretica (Martius) Handlos Plowman 10102 AF312249 AY624125
Weldenia Schult. f.
Weldenia candida Schult. f. Chase 592 AF312245 *AY624126
OUTGROUPS:
Aneilema R. Br.
Aneilema calceolus Brenan Faden & Faden 77/565 AF036889 AY198180
Cartonema R. Br.
Cartonema philydroides F. Muell. Horticulture–Munich Botanical Garden AF036890 AY198181
(e.g., Olmstead and Palmer 1994; Kim and Jansen 1995;
Terry et al. 1997; Backlund et al. 2000; Givnish et al. 2000).
The objectives of this study were to determine phyloge-
netic relationships among members of tribe Tradescantieae
using ndhF and rbcL sequence data and to use the resulting
phylogenies to evaluate systematic and biogeographical
trends within tribe Tradescantieae.
MATERIALS AND METHODS
The gene ndhF was sequenced from a single plant of 19
species, representing 19 genera from Tradescantieae (Table
1). Additionally, a single plant from one species each of
Cartonema and Aneilema were included for outgroup com-
parison, based upon results of Evans et al. (2003). All sam-
ples used in this study were from the same DNA samples
used in Evans et al. (2003).
Total DNA for all species was extracted from frozen leaf
tissue following the CTAB procedure of Doyle and Doyle
(1987) as modified by Smith et al. (1991). The ndhF gene
was amplified in two fragments on a Hybaid thermocycler
(Thermo Electron Corporation, Marietta, Ohio, USA), using
deoxynucleotides from United States Biochemical (Cleve-
land, Ohio, USA), and Taq polymerase from Promega (Mad-
ison, Wisconsin, USA). Primers for the 5
9
-region annealed
near positions 32 (forward) and 1318 (reverse) of ndhF(Ter-
ry et al. 1997). For amplification of the 3
9
-region, primers
that annealed near position 972 (forward) and 2110 (reverse)
were used (Olmstead and Sweere 1994). Sequencing reac-
tions were performed using BigDye
y
Terminator Reaction
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Mix (Applied Biosystems, Inc., Foster City, California,
USA) or the DYEnamic ET terminator cycle sequencing kit
(Amersham Biosciences Corporation, Piscatawy, New Jer-
sey, USA). Cycle sequencing fragments were purified using
Centri-Sep columns (Princeton Separations, Inc., Adelphia,
New Jersey, USA) and sequenced on an ABI 310 automated
sequencer before being assembled using Autoassembler vers.
2.0 (ABI Prism
t
). All sequences were manually aligned be-
fore phylogenetic analysis. The resulting ndhF data set was
combined with rbcL data from Evans et al. (2003) and 47
morphological characters from Evans et al. (2000a).
Phylogenetic Analyses
All phylogenetic analyses were performed using PAUP*
vers. 4.0b4a (Swofford 2003). A multiple-islands approach
was used to find the most parsimonious trees (Maddison
1991). A heuristic search was conducted using a random
addition sequence with 1000 replicates, tree-bisection-recon-
nection (TBR) branch swapping, steepest descent on, and
100 trees saved for each replicate. Bootstrap and decay val-
ues were determined to evaluate support for each node. For
the bootstrap analysis, one hundred replicate searches were
performed using TBR with random addition of 100 repli-
cates and 100 trees saved from each replicate. Decay values
were determined using AutoDecay vers. 2.9.9 (Eriksson
1997) to produce a constraint command file. This file was
executed in PAUP* using a heuristic search, TBR branch
swapping, and 10 replications of the random addition se-
quence. The ‘Converse Enforce’ command in PAUP* was
employed to save only those trees lacking the clade being
examined.
Character State Mapping
To examine biogeographical trends within the tribe, geo-
graphic distributions were overlaid onto the total data phy-
logeny using MacClade vers. 4.0 (Maddison and Maddison
2000) assuming accelerated transformation (ACCTRANS).
RESULTS
One most parsimonious tree of 1392 steps was produced
from the combined ndhF/rbcL data set; consistency index
(CI)
5
0.69, retention index (RI)
5
0.61 without autapo-
morphies (Fig. 1). The phylogeny was largely congruent
with the rbcL phylogeny (see Evans et al. 2003), though the
support for the deeper clades was notably higher in the com-
bined analysis (Fig. 1). The shallow branches were well sup-
ported, with the exception of the clade containing Callisia,
Tripogandra, and Elasis (62% bootstrap). The deeper
branches were also relatively well supported, though two of
the deeper branches were supported by bootstrap values of
less than 70% (Fig. 1).
When morphological data were added to the rbcL/ndhF
data, two most-parsimonious trees of 1540 steps were found;
CI
5
0.66, RI
5
0.58 without autapomorphies (Fig. 2). One
tree was identical to the rbcL/ndhF phylogeny and the other
differed in the position of Elasis.
Of the seven subtribes within Tradescantieae, Coleotry-
pinae, and Cyanotinae were monophyletic, Tradescantiinae
were paraphyletic (due to the inclusion of Elasis, a member
of Thyrsantheminae, in the clade), and Thyrsantheminae and
Dichorisandrinae were polyphyletic. Members of Dichori-
sandrinae were placed into two clades: a Dichorisandra and
a Siderasis clade, and a Cochliostema/Plowmanianthus/Geo-
genanthus clade. Subtribe Palisotinae is comprised of a sin-
gle genus, Palisota, and subtribe Streptoliriinae (three gen-
era) was represented by a single genus, Spatholirion.
DISCUSSION
The rbcL and combined rbcL/morphology data sets placed
Palisota as sister to all genera of Commelinaceae except
Cartonema, making tribe Tradescantieae paraphyletic (Evans
et al. 2003). Deep branches in the rbcL and rbcL/morphol-
ogy phylogenies were only weakly supported, however, as
determined by bootstrap and decay values, and basal rela-
tionships within the tribe could not be inferred with confi-
dence.
Addition of ndhF produced a monophyletic Tradescan-
tieae (both the ndhF/rbcL and ndhF/rbcL/morphology data
sets), with Palisota sister to the rest of the tribe (Fig. 1, 2).
While support for most clades in the total data phylogeny
was high, the branch uniting Palisota with the remainder of
Tradescantieae is supported by a decay value of only 1 (or
2 when morphology is included), and a bootstrap value of
56% (less than 50% when morphology is included) (Fig. 1,
2). Additionally, only a single representative of tribe Com-
melineae, Aneilema, was included in this study. Until addi-
tional representatives of Commelineae are examined, as well
as sequences from additional rapidly evolving regions, the
exact placement of Palisota, and thus the monophyly of tribe
Tradescantieae, will remain unclear.
Members of subtribe Dichorisandrinae are found in two
separate clades (Fig. 1, 2). Analysis of morphological data
produced a highly polyphyletic Dichorisandrinae, but a high
degree of homoplasy among specific morphological charac-
ters makes those relationships suspect (Evans et al. 2000a).
The combined rbcL/morphology data yielded a monophy-
letic Dichorisandrinae, albeit with low bootstrap and decay
support (Evans et al. 2003). Hardy (2001) examined mor-
phological and molecular data to evaluate relationships with-
in Dichorisandrinae and found support for a monophyletic
subtribe. That study, while providing a thorough sampling
within Dichorisandrinae, did not include many representa-
tives from other subtribes of Tradescantieae. Additionally,
the jackknife value (Farris 1997) was relatively low for the
branch supporting the monophyly of the subtribe.
Nearly every analysis to date (except for morphology
alone) places the five genera of Dichorisandrinae into two
well-supported clades with Dichorisandra and Siderasis in
one and Cochliostema, Plowmanianthus (represented as
‘undescribed genus’ in Evans et al. [2000a, b, 2003]), and
Geogenanthus in the other. While this analysis places these
clades separate from each other, a tree of only one additional
step is required to obtain a monophyletic subtribe. All mem-
bers of the subtribe share a similar karyotype of 19 large
chromosomes (Jones and Jopling 1972; Faden and Hunt
1991; Faden 1998), but no unique morphological characters
are known that unambiguously unite these five genera. In-
clusion of sequences from additional rapidly evolving re-
gions of the genome, as well as more thorough sampling of
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Fig. 1.—Single most-parsimonious tree produced by cladistic analysis of rbcL and ndhF sequences in Commelinaceae, tribe Tradescan-
tieae (length
5
1392 steps, CI
5
0.69, RI
5
0.61). Numbers above each branch indicate bootstrap support; numbers below each branch
indicate the number of additional steps required before that branch collapses (decay value). Subtribal and tribal affinities are indicated with
the bars to the right of the cladogram.
taxa within Dichorisandrinae will likely be needed to con-
fidently determine the monophyly of the subtribe.
Subtribe Thyrsantheminae is polyphyletic, with represen-
tatives appearing in three different clades (Fig. 1, 2). The
rbcL/morphology data united Weldenia and Thyrsanthemum,
placed Elasis in a clade with members of subtribe Trades-
cantiinae, but failed to resolve the position of Tinantia
(Evans et al. 2003). Addition of ndhF has yielded the same
set of relationships, but with stronger support for each clade.
Additionally, the placement of Tinantia has been resolved as
sister to a clade containing the remainder of Thyrsanthemi-
nae and tribe Tradescantieae, again with strong support (Fig.
1, 2).
There is clearly a relationship between Elasis (subtribe
Thyrsantheminae) and members of subtribe Tradescantiinae.
Molecular data alone (rbcL/ndhF) place Elasis well within
the Tradescantiinae clade (Fig. 1). With the addition of mor-
phological data, the position of Elasis with respect to Tra-
descantiinae becomes unresolved, with Elasis being placed
either within or sister to the subtribe (Fig. 2). All members
of subtribe Tradescantiinae share a common inflorescence
type, in which two cincinni are fused back-to-back or in
which two-to-several stipitate cincinni form a pseudoumbel
(Faden and Hunt 1991). Evans et al. (2003) hypothesized
that Elasis, which lacks this inflorescence type, may repre-
sent a reduced form in which one of the two cincinni has
been lost. Alternatively, if Elasis is resolved as sister to Tra-
descantiinae, then fused cincinni within the subtribe may
represent the derived condition with respect to Elasis. As
there are currently no morphological characters known that
clearly unite Elasis with members of Tradescantiinae, ex-
amination of inflorescence structure and development might
shed light upon this unresolved node of the phylogeny.
The Old World subtribes Coleotrypinae and Cyanotinae
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Fig. 2.—One of two most-parsimonious trees produced by cladistic analysis of combined morphology/rbcL/ndhF in Commelinaceae tribe
Tradescantieae (length
5
1540 steps, CI
5
0.66, RI
5
0.58). Numbers above each branch indicate bootstrap support; numbers below each
branch indicate the number of additional steps required before that branch collapses (decay value). Gray line represents branch that collapses
in strict consensus of the two most-parsimonious trees. Arrow indicates the position of branches in the second most-parsimonious tree.
Subtribal and tribal affinities are indicated with the bars to the right of the cladogram.
are each monophyletic and together form a monophyletic
Old World clade (Fig. 1, 2). The monophyly of each of these
two subtribes is strongly supported by both molecular and
morphological data. The inflorescence of members of Co-
leotrypinae consists of axillary, highly congested cincinni
and perforates the leaf sheath. The Cyanotinae are united by
the seeds with a terminal embryotega. As noted in Evans et
al. (2003), biogeography provides some evidence of rela-
tionship between these two subtribes, but no morphological
characters are known that unambiguously unite them.
The addition of ndhF data has helped to clarify the bio-
geographical relationships of Cyanotinae and Coleotrypinae
to other Tradescantieae subtribes. Of the seven subtribes
within Tradescantieae, three (Dichorisandrinae, Thyrsan-
theminae, and Tradescantiinae) are found exclusively in the
New World and four (Coleotrypinae, Cyanotinae, Palisoti-
nae, and Streptoliriinae) are found exclusively in the Old
World (Faden and Hunt 1991; Hunt 1993, 1994; Faden
1998) (Fig. 3). The placement of Coleotrypinae and Cyano-
tinae within, but not sister to, the New World clade was
noted by Evans et al. (2003) in their rbcL/morphology anal-
ysis. Three possible scenarios were proposed to explain the
distribution: (1) a single shift from the Old World to the New
World, either through vicariance or dispersal, followed by a
single dispersal back to the Old World (ACCTRANS opti-
mization); (2) two independent introductions to the New
World (DELTRANS optimization); or (3) the Boreotropical
Flora Hypothesis (Wolfe 1975), in which the current distri-
bution reflects a relictual distribution of a formerly wide-
spread northern temperate group. The third scenario was de-
termined to be unlikely due to the relatively early divergence
of Dichorisandrinae and the relatively derived position of
Tradescantiinae. The first two scenarios, however, were
equally likely as a result of the ambiguous optimization of
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Fig. 3.—Geographic distributions mapped onto single most-parsimonious tree produced by analysis of rbcL/ndhF sequences. A single
shift from the Old World to the New World, followed by a dispersal back to the Old World is supported, due to the position of Old World
subtribes Coleotrypinae and Cyanotinae nested well within a New World clade.
biogeography onto the rbcL/morphology phylogeny (Fig. 6
of Evans et al. 2003). The addition of ndhF to the analysis
clarifies the issue by placing the Old World subtribes Coleo-
trypinae and Cyanotinae well within the New World clade,
thus removing ambiguity to the optimization of biogeogra-
phy and favoring the first hypothesis (one shift from the Old
World to the New World followed by dispersal back to the
Old World; Fig 3).
ACKNOWLEDGMENTS
We would like to thank Dave Cameron and Gerrit Heet-
derks for assistance in the lab, and Greg Brown and Dorothy
Tuthill for assistance with data analyses and preparation of
the manuscript. Chris Hardy and an anonymous reviewer
provided many helpful comments. This work was supported
by NSF-REU grants DBI-0139035 and DBI-9820571 to the
Hope College Biology Department.
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... BURNS ET AL.: COMMELINACEAE PHYLOGENY 269 et al. 2000 ) and molecular ( Bergamo 2003 ; Evans et al. 2003 ; Wade et al. 2006 ) data. Evans et al. (2000 ; 2003 ) sampled most of the currently recognized genera, Wade et al. (2006) focused on the tribe Tradescantieae, and Bergamo's (2003) study was restricted to Callisia . ...
... BURNS ET AL.: COMMELINACEAE PHYLOGENY 269 et al. 2000 ) and molecular ( Bergamo 2003 ; Evans et al. 2003 ; Wade et al. 2006 ) data. Evans et al. (2000 ; 2003 ) sampled most of the currently recognized genera, Wade et al. (2006) focused on the tribe Tradescantieae, and Bergamo's (2003) study was restricted to Callisia . Analyses with the chloroplast region rbcL provided strong support for a monophyletic Commelinaceae ( Evans et al. 2003 ). ...
... Analyses with the chloroplast region rbcL provided strong support for a monophyletic Commelinaceae ( Evans et al. 2003 ). Subtribal relationships in the Tradescantieae were also partly supported in Evans et al. (2003) and Wade et al. (2006) , with the exceptions that subtribes Tradescantiinae Rohw., Thyrsantheminae Faden & D. R. Hunt, and Dichorisandrinae (Pichon) Faden & D. R. Hunt were not monophyletic in parsimony analyses of rbcL and ndhF ( Wade et al. 2006 ). Within the Tradescantieae, Gibasis was nested within Tradescantia , and Callisia was not monophyletic ( Evans et al. 2003 ), containing Tripogandra within it. ...
Data
Full-text available
... BURNS ET AL.: COMMELINACEAE PHYLOGENY 269 et al. 2000 ) and molecular ( Bergamo 2003 ; Evans et al. 2003 ; Wade et al. 2006 ) data. Evans et al. (2000 ; 2003 ) sampled most of the currently recognized genera, Wade et al. (2006) focused on the tribe Tradescantieae, and Bergamo's (2003) study was restricted to Callisia . ...
... BURNS ET AL.: COMMELINACEAE PHYLOGENY 269 et al. 2000 ) and molecular ( Bergamo 2003 ; Evans et al. 2003 ; Wade et al. 2006 ) data. Evans et al. (2000 ; 2003 ) sampled most of the currently recognized genera, Wade et al. (2006) focused on the tribe Tradescantieae, and Bergamo's (2003) study was restricted to Callisia . Analyses with the chloroplast region rbcL provided strong support for a monophyletic Commelinaceae ( Evans et al. 2003 ). ...
... Analyses with the chloroplast region rbcL provided strong support for a monophyletic Commelinaceae ( Evans et al. 2003 ). Subtribal relationships in the Tradescantieae were also partly supported in Evans et al. (2003) and Wade et al. (2006) , with the exceptions that subtribes Tradescantiinae Rohw., Thyrsantheminae Faden & D. R. Hunt, and Dichorisandrinae (Pichon) Faden & D. R. Hunt were not monophyletic in parsimony analyses of rbcL and ndhF ( Wade et al. 2006 ). Within the Tradescantieae, Gibasis was nested within Tradescantia , and Callisia was not monophyletic ( Evans et al. 2003 ), containing Tripogandra within it. ...
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The Commelinaceae are a pantropical family of monocotyledonous herbs. Previous phylogenies in Commelinaceae have emphasized sampling among genera. We extended this previous work by sampling multiple species within some of the largest genera of Commelinaceae (especially Commelina and Tradescantia, and also including Callisia, Cyanotis, Gibasis, and Murdannia), and by sequencing noncoding regions both of the nuclear ribosomal DNA region, 5S NTS, and the chloroplast region, trnL-trnF. We generated a phylogenetic hypothesis for 68 Commelinaceae that partially tests previous morphological, taxonomic classifications. We found little evidence for conflict between nuclear and chloroplast regions for Tradescantia, Murdannia, and Callisia, and some evidence for conflict between the two regions for Commelina, though conflicting regions of the phylogeny were only weakly supported by bootstrap analyses. We found subtribe Tradescantieae to be paraphyletic, consistent with an rbcL study, though with a different topology than that produced by rbcL. In addition, subtribe Commelineae was monophyletic with strong support. We found Callisia to be polyphyletic, consistent with some previous molecular phylogenetic studies, and we found Tradescantia, Gibasis, Cyanotis, Commelina, and Murdannia, to be monophyletic. The molecular phylogenies presented here generally supported previous taxonomic classifications.
... The intergeneric phylogenetic relationships of the Commelinaceae have been examined by Evans et al. (2003) by combining rbcL and morphological datasets, where one (to three) species were used to represent 30 genera. Burns et al. (2011) and Wade et al. (2006) also investigated the phylogenetic relationships of Commelinaceae. While some of their findings differed from those of Evans et al. (2003), none of these changed the apparent relationships between the genera present in Australia. ...
... Dichorisandra has been recovered as monophyletic by different morphological and phylogenetic studies. It is closely related to Siderasis rafinesque (1837: 67), a monospecific genus in the Brazilian atlantic forest (evans et al. 2000;Hardy 2001;evans et al. 2003;Wade et al. 2006;Burns et al. 2011;Hertweck & Pires 2014). Commelinaceae is economically important due to the ornamental value of many genera, with its species being cultivated since early days due to their beautiful foliage and flowers (Hunt 2001). ...
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Dichorisandra picta has been considered a name of dubious application due to the lack of known herbarium specimens, and consequently lack of a type specimen, and information regarding its natural distribution. Recent field, herbaria and literature studies, focusing on the species of Commelinaceae from Rio de Janeiro state, clarified the identity and application of this enigmatic name. As a result, the typification of the names related to D. picta is presented, along with the first complete description for this species, field photographs and a distribution map. Dichorisandra picta is also compared with the remaining species of the D. acaulis morphological group.
... The strong support for two Gibasis species in two different Tradescantia clades also indicates that the diagnostic character of a paired, condensed inflorescence structure is perhaps reversible. We support the assertion of Wade et al. (2006) that developmental evidence is required to determine the mode of inflorescence evolution in this problematic clade. The lability in inflorescence morphology in the Tradescantia alliance may be related to variation in flowering phenology and pollination ecology among species. ...
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Abstract— The Tradescantia alliance (subtribes Tradescantiinae and Thyrsantheminae of tribe Tradescantieae, family Commelinaceae) comprises a group of closely related New World genera exhibiting considerable variation in morphological, life history, and genomic traits. Despite ecological and cytogenetic significance of the Tradescantia alliance, phylogenetic relationships among genera and species remain uncertain. In particular, variation in inflorescence morphology has confounded classification and taxonomy. We inferred phylogenetic relationships using two plastid loci (rpL16, trnL-trnF) for 85 taxa in Commelinaceae, with sampling focused in the Tradescantia alliance. Constraint tests supported only subtribe Tradescantiinae, Tripogandra and Tinantia as monophyletic, with Tripogandra nested within Callisia. We estimated ancestral states for both breeding system and inflorescence condensation and tested for a correlation. Inflorescence morphology, an important character for generic identification, is more labile than previously expected, with condensed inflorescences evolving twice with three subsequent reversals. Breeding system evolution is more complex, with many more switches between self compatibility and self incompatibility and more uncertainty in ancestral state estimates. The presence of self compatible and incompatible species allowed us to test the hypothesis that self compatible species will have condensed inflorescences, as less allocation to floral display is necessary. While we did not find a correlation between self compatibility and inflorescence condensation, we propose additional floral and inflorescence characteristics that may have contributed to variation in breeding system.
... According to Faden & sequence data, confirm the monophyly of various subtribes, but it is not yet clear whether Dichorisandrinae is monophyletic. Molecular data, however, show Dichorisandra and Siderasis as sister groups (Wade et al. 2003;Evans et al. 2003). ...
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Five new species of the genus Dichorisandra J. C. Mikan are described based on field, herbarium and cultivation studies. The species described here are only known from the Atlantic rain forest from the State of Bahia, Brazil and have anthers with introrse longitudinal slits that are functionally poricidal. D. subtilis Aona & M. C. E. Amaral is characterised by its small habit, erect, densely pilose leaves, flowers in congested inflorescences, 5 stamens and a verrucose ovary. D. variegata Aona & Faden presents terminal, erect or sometimes decumbent inflorescences sprouting from the base of the plant, leaf blades sparsely to densely pilose and with two white longitudinal broad stripes above, and 5 (– 6) stamens. D. jardimii Aona & M. C. E. Amaral is characterised by the axillary inflorescences that perforate the leaf sheaths and arise either directly from the rhizome or from normal terrestrial branches, 5 stamens, a verrucose ovary and cylindrical fruits. D. ordinatiflora Aona & Faden presents axillary inflorescences that perforate the leaf sheaths, inflorescences distributed evenly along the stem, and a reddish indumentum. D. conglomerata Aona & M. C. E. Amaral can be recognised by its completely glabrous leaves, terminal inflorescences, the large number of flowers per cincinnus (7 – 10 flowers), and 5 stamens. Discussion of relevant characters, comparisons with closest relatives, descriptions, information on conservation status and illustrations are provided.
... ). Along with that, the increased number of Palisota samples included within this study increased the confidence in which Palisota can be place as sister to the tribe Tradescantieae as found in previous studies (Evans et al. 2003, Wade et al. 2006). These findings contradict previous placement of Palisota based solely on morphology (Faden and Hunt, 1991). ...
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Palynological data emphasize the presence of two distinctive provinces during the Late Cretaceous, one including eastern North America and Europe and a second including the major part of Asia and western North America. The distinction between these two provinces became increasingly blurred during the Paleogene. During the Eocene, the ram forests of both Europe and western North America shared numerous genera, both extinct and extant. The great majority of the latter and most of the closest extant relatives of the former now occur in the Indomalayan region. It is thus clear that much of the present Indomalayan flora represents a relict of a once widespread Northern Hemisphere tropical (s.l.) flora, one that has largely (but not entirely) been eliminated from the New World. Among the possible New World survivors of this boreotropical flora are some of the dry Caribbean genera, which could have been derived from lineages of the dry tropical vegetation of the Gulf Coast Eocene; only a handful of present Neotropical lowland rain forest genera appear to be boreotropical relicts.
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A new approach to phylogenetic analysis, parsimony jackknifing, uses simple parsimony calculations combined with resampling of characters to arrive at a tree comprising well-supported groups. This is usually much the same as the consensus of most-parsimonious trees found from extensive multiple-tree calculations, but the new method is thousands of times faster, allowing analysis of much larger data matrices, and also provides information on the strength of support for different groups. Jackknife frequencies provide a more reliable assessment of support than do alternative methods, notably “confidence probability” (CP) and T-PTP testing.
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The internal transcribed spacer (ITS) region of the 18 S–25 S nuclear ribosomal DNA repeat was sequenced from 19 populations of the tribeLactuceae, including all species of dwarf dandelion (Krigia) and five outgroup genera. The incidence of length changes and base substitutions was at least two times higher for ITS 1 than ITS 2. Interspecific sequence divergence withinKrigia averaged 9.62% (1.61%–15.19%) and 4.26% (0%–6.64%) in ITS 1 and ITS 2, respectively. Intergeneric sequence divergence ranged from 15.6% to 44.5% in ITS 1 and from 8.0% to 28.6% in ITS 2. High sequence divergence and homoplasy among genera of tribeLactuceae suggest that the phylogenetic utility of ITS sequence data is limited to interspecific studies or comparisons among closely related genera. Trees generated from ITS sequences are essentially identical to those from restriction site comparisons of the entire nuclear ribosomal (nr) DNA region. The degree of tree resolution differed depending on how gaps were treated in phylogenetic analyses. The ITS trees were congruent with the chloroplast DNA and morphological phylogenies in three major ways: 1) the sister group relationship betweenKrigia andPyrrhopappus; 2) the recognition of two monophyletic sections,Krigia andCymbia, in genusKrigia; and 3) the monophyly of theK. occidentalis-K. cespitosa clade in sect.Cymbia. However, the two nrDNA-based trees are not congruent with morphology/chloroplast DNA-based trees for the interspecific relationships in sect.Krigia. An average of 22.5% incongruence was observed among fourKrigia data sets. The relatively high degree of incongruence among data sets is due primarily to conflict between trees based on nrDNA and morphological/cpDNA data. The incongruence is probably due to the concerted evolution of nrDNA repeating units. The results fromKrigia and theLactuceae suggest that nrDNA data may have limited utility in phylogenetic studies of plants, especially in groups which exhibit high levels of sequence divergence. Our combined phylogenetic analysis as a total evidence shows the least conflict to each of the individual data sets.