Vereecken N.J.,Free University of Brussels |
Wilson C.A.,500 North College Avenue |
Hotling S.,TU Braunschweig |
Schulz S.,TU Braunschweig |
And 2 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2012
Pollination by sexual deception is arguably one of the most unusual liaisons linking plants and insects, and perhaps the most illustrative example of extreme floral specialization in angiosperms. While considerable progress has been made in understanding the floral traits involved in sexual deception, less is known about how this remarkable mimicry system might have arisen, the role of pre-adaptations in promoting its evolution and its extent as a pollination mechanism outside the few groups of plants (primarily orchids) where it has been described to date. In the Euro-Mediterranean region, pollination by sexual deception is traditionally considered to be the hallmark of the orchid genus Ophrys. Here, we introduce two new cases outside of Ophrys, in plant groups dominated by generalized, shelter-mimicking species. On the basis of phylogenetic reconstructions of ancestral pollination strategies, we provide evidence for independent and bidirectional evolutionary transitions between generalized (shelter mimicry) and specialized (sexual deception) pollination strategies in three groups of flowering plants, and suggest that pseudocopulation has evolved from pre-adaptations (floral colours, shapes and odour bouquets) that selectively attract male pollinators through shelter mimicry. These findings, along with comparative analyses of floral traits (colours and scents), shed light on particular phenotypic changes that might have fuelled the parallel evolution of these extraordinary pollination strategies. Collectively, our results provide the first substantive insights into how pollination sexual deception might have evolved in the Euro-Mediterranean region, and demonstrate that even the most extreme cases of pollinator specialization can reverse to more generalized interactions, breaking 'Cope's rule of specialization'. © The Royal Society 2012.
Voznesenskaya E.V.,RAS Komarov Botanical Institute |
Koteyeva N.K.,RAS Komarov Botanical Institute |
Edwards G.E.,Washington State University |
Ocampo G.,500 North College Avenue |
Ocampo G.,California Academy of Sciences
Journal of Experimental Botany | Year: 2010
Portulacaceae is one of 19 families of terrestrial plants in which species having C4 photosynthesis have been found. Representative species from major clades of the genus Portulaca were studied to characterize the forms of photosynthesis structurally and biochemically. The species P. amilis, P. grandiflora, P. molokiniensis, P. oleracea, P. pilosa, and P. umbraticola belong to the subgenus Portulaca and are C4 plants based on leaf carbon isotope values, Kranz anatomy, and expression of key C4 enzymes. Portulaca umbraticola, clade Umbraticola, is NADP-malic enzyme (NADP-ME)-type C4 species, while P. oleracea and P. molokiniensis in clade Oleracea are NAD-ME-type C4 species, all having different forms of Atriplicoid-type leaf anatomy. In clade Pilosa, P. amilis, P. grandiflora, and P. pilosa are NADP-ME-type C4 species. They have Pilosoid-type anatomy in which Kranz tissues enclose peripheral vascular bundles with water storage in the centre of the leaf. Portulaca cf. bicolor, which belongs to subgenus Portulacella, is an NADP-ME C4 species with Portulacelloid-type anatomy; it has well-developed Kranz chlorenchyma surrounding lateral veins distributed in one plane under the adaxial epidermis with water storage cells underneath. Portulaca cryptopetala (clade Oleracea), an endemic species from central South America, was identified as a C 3-C4 based on its intermediate CO2 compensation point and selective localization of glycine decarboxylase of the photorespiratory pathway in mitochondria of bundle sheath cells. The C 4 Portulaca species which were examined also have cotyledons with Kranz-type anatomy, while the stems of all species have C3-type photosynthetic cells. The results indicate that multiple structural and biochemical forms of C4 photosynthesis evolved in genus Portulaca. © 2010 The Author.
Morawetz J.J.,Ohio State University |
Morawetz J.J.,500 North College Avenue |
Randle C.P.,Sam Houston State University |
Wolfe A.D.,Ohio State University
Taxon | Year: 2010
The tropical clade of Orobanchaceae contains approximately forty genera, typically with fewer than ten species each, and contributes significantly to the variation in floral morphology found within the family. Despite the economic importance of this clade, which contains three of four most important genera of crop parasites within the family, it has been under-sampled in previous phylogenies. We tested the monophyly of the tropical clade and its major genera using DNA sequences from the nuclear (internal transcribed spacer) and plastid (rpl16, trnT-L) genomes. The tropical clade was strongly supported as mono-phyletic in all analyses, and four main clades were recovered. The earliest diverging lineage from the remainder of the tropical clade is comprised of the shrubby genera Asepalum and Cyclocheilon, previously placed within Cyclocheilaceae. The atypical holoparasitic Alectra alba was shown to belong within the primarily holoparasitic Harveya, and the hemiparasitic Harveya obtusifolia was shown to belong to an otherwise holoparasitic lineage within Harveya. Both New World Melasma species were included here for the first time, and these were shown to be more closely related to the Neotropical hemiparasitic Escobedia than the African Melasma lineage. These results support a previous study recognizing Nesogenes within the tropical clade of Orobanchaceae rather than the separate family Nesogenaceae.
Porter J.M.,500 North College Avenue |
Johnson L.A.,Brigham Young University |
Wilken D.,Santa Barbara Botanic Garden
Systematic Botany | Year: 2010
The genus Ipomopsis (Polemoniaceae) encompasses about 29 species and 24 subspecies generally divided into three sections: sect. Ipomopsis, sect. Microgilia, and sect. Phloganthea. We employed maximum likelihood and Bayesian inference of DNA sequences from the nuclear ribosomal ITS region (ITS1, 5.8S ribosomal subunit, ITS2) and the chloroplast trnLF region (trnL intron + trnLtrnF intergenic spacer) to estimate phylogenetic relationships within this genus and its placement among other genera of Polemoniaceae. The chloroplast and combined sequences provide support for the monophyly of Ipomopsis, but only if four species previously included in the genus are removed: Ipomopsis havardii, I. sonorae, Microgilia minutiflora (= I. minutiflora), and Loeseliastrum depressum (= I. depressa). Of the three sections, two are conditionally supported as being monophyletic. Section Microgilia (with 11 species and 11 infra-specific taxa) is supported as monophyletic if I. polycladon, I. sonorae, I. depressa, and I. minutiflora (the type of the section) are removed. This clade is treated here as section Elaphocera. Section Ipomopsis is inferred to be monophyletic with the inclusion of several members of sect. Phloganthea (I. multiflora, I. pinnata, and I. polyantha). There is no support for monophyly or paraphyly of sect. Phloganthea. The Giliopsis group (I. effusa, I. guttata, and I. tenuifolia) is supported as monophyletic by both data sets, and the cpDNA sequences place it as sister to the remainder of Ipomopsis. This clade is treated as a new section, Giliopsis. Nuclear data place Giliopsis in a clade with Ipomopsis havardii, I. sonorae, Microgilia minutiflora, Loeseliastrum depressum, Eriastrum spp., Langloisia, and Dayia grantii. Using the Eocene fossil Gilisenium hueberii to calibrate the most recent common ancestor of tribe Gilieae, we estimate that Ipomopsis has its origin 28.2 ± 0.40-39.0 ± 1.14 MYA (trnL-F and ITS, respectively). Using this same relaxed clock, the node (or coalescent event) that defines the I. aggregata complex is dated at 16.2 ± 0.38 and 27.1 ± 0.83 MYA (trnL-F and ITS, respectively). The deep divergence of the I. aggregata complex suggests that reticulation, rather than lineage sorting, is the source of conflict among phylogenetic markers used to infer the placement of I. macrosiphon. © Copyright 2010 by the American Society of Plant Taxonomists.
Ferrucci M.S.,CONICET |
Steinmann V.W.,500 North College Avenue
Systematic Botany | Year: 2016
Serjania rzedowskiana (Sapindaceae-Paullinieae), a new species from the Zicuirán-Infiernillo Biosphere Reserve of Michoacán, Mexico, is described and illustrated. The novelty differs from its congeners by having fruits with 3 indehiscent, wingless cocci, and by its sub-transversely obovoid seeds that occupy less than half of the locule. In addition, micromorphological features of the leaves, flowers and pollen grains are investigated. The distinctive fruit morphology of this new species is discussed in relation to other species of Serjania. In addition, a key is provided to differentiate the new species from other Mexican Serjania with similar vegetative characters (i.e. trifoliolate leaves and flowering branchlets with three peripheral vascular cylinders). © 2016 by the American Society of Plant Taxonomists.
Poinar Jr. G.,Oregon State University |
Columbus J.T.,500 North College Avenue
Historical Biology | Year: 2013
Alarista succina gen. et sp. nov. (Poaceae) is described from a single floret preserved in amber of Tertiary age originating from the Dominican Republic. The new genus is characterised by (1) a narrow-winged lemma awn, (2) numerous (as many as 17) lemma nerves, (3) a lengthy rachilla internode (implying a lax spikelet), (4) sinuous-margined long cells, (5) silica cells arranged transversely, (6) stomatal subsidiaries low domed and (7) papillae. The epidermal features are characteristic of the abaxial leaf blade surface of members of the Bambusoideae and the fossil is placed in this group. htp://zoobank.org/033FCBF4-CD61-4C85-97E4-8418C9ABA5E6. © 2013 Copyright Taylor and Francis Group, LLC.
Karst L.,8730 SW Washington Dr. |
Wilson C.A.,500 North College Avenue
Systematic Botany | Year: 2012
Sisyrinchium (Iridaceae) is a New World genus of approximately 140 species. Seventy-five accessions from sixty species representing the geographical and morphological diversity present within the genus were included in this study. Maximum likelihood and Bayesian inference analyses utilized ITS and matK/trnK datasets, analyzed separately and combined. Based on this study the genus Sisyrinchium is monophyletic and is sister to Olsynium. The currently accepted subgenera, Echthronema and Sisyrinchium, are not monophyletic. Instead, all analyses revealed eight major clades, which correspond to named sections or are given informal clade names. Relationships among the eight major clades are resolved except for early diverging clades where topologies for the two DNA-region trees did not agree. Additionally, several widespread species are not monophyletic based on data from these two molecular markers. © Copyright 2012 by the American Society of Plant Taxonomists.
Wheeler A.S.,500 North College Avenue |
Wilson C.A.,500 North College Avenue
Systematic Botany | Year: 2014
Three series, Prismaticae, Tripetalae, and Laevigatae, in Iris subgenus Limniris comprise a clade of nine species with an affinity for wetland environments. Prior work has failed to resolve phylogenetic relationships among these taxa. We used maximum likelihood and Bayesian inference methods to analyze plastid and nuclear ribosomal ITS sequence data to infer a robust phylogeny for this circumboreal group. Our analyses recovered clades that do not reflect current series circumscriptions and show that species from Tripetalae and Laevigatae comprise one clade. Species relationships also do not reflect geographic proximity, as Asian and North American species do not assort into regional clades. This finding suggests that multiple exchanges between Asia and North America are required to explain current distributions and refutes the hypothesis that Asian taxa are the earliest diverging lineage within the clade. © Copyright 2014 by the American Society of Plant Taxonomists.
Tripp E.A.,500 North College Avenue |
Fatimah S.,500 North College Avenue
American Journal of Botany | Year: 2012
Premise of the study: Anatomical and morphological features of Satanocrater were studied to test hypotheses of xeric adaptations in the genus, which is endemic to arid tropical Africa These features, together with molecular data, were used to test the phylogenetic placement of Satanocrater within the large plant family Acanthaceae Methods: We undertook a comparative study of four species of Satanocrater Carbon isotope ratios were generated to test a hypothesis of C4 photosynthesis Molecular data from chloroplast (trnG-trnS, trnG-trnR, psbA-trnH) and nuclear (Eif3E) loci were used to test the placement of Satanocrater within Acanthaceae Key results: Anatomical features reflecting xeric adaptations of species of Satanocrater included a thick-walled epidermis, thick cuticle, abundant trichomes and glandular scales, stomata overarched by subsidiary cells, tightly packed mesophyll cells, and well-developed palisade parenchyma on both leaf surfaces Although two species had enlarged bundle sheath cells, a feature often implicated in C4 photosynthesis, isotope ratios indicated all species of Satanocrater use the C4 pathway Molecular data resolved Satanocrater within tribe Ruellieae with strong support Within Ruellieae, our data suggest that pollen morphology of Satanocrater may represent an intermediate stage in a transition series Conclusions: Anatomical and morphological features of Satanocrater reflect adaptation to xeric environments and add new information about the biology of xerophytes Morphological and molecular data place Satanocrater in the tribe Ruellieae with confidence This study adds to our capacity to test hypotheses of broad evolutionary and ecological interest in a diverse and important family of flowering plants © 2012 Botanical Society of America.
Wilson C.A.,500 North College Avenue
Taxon | Year: 2011
Phylogenetic relationships among the six Iris subgenera were reconstructed based on chloroplast sequence data using maximum likelihood and Bayesian inference methods. Previous studies indicated that the current subgeneric classification based on an intuitive interpretation of morphology was not concordant with evolution in Iris. This study more than doubled the number of taxa sampled and increased the number of molecular markers providing a more robust assessment of phylogeny. Iris subg. Nepalensis and subg. Xiphium were resolved as monophyletic, while subg. Hermodactyloides, subg. Limniris, subg. Iris and subg. Scorpiris were not. The three monotypic genera, Belamcanda, Pardanthopsis and Hermodactylus, recognized by some workers were resolved within Iris with strong support. The three bulbous subgenera, sometimes recognized as distinct genera, were resolved within Iris. A preliminary subgeneric classification is presented.