E. F Smets
Universiteit Leiden, Naturalis Biodiversity Center, Faculty Member
Pleurothallidinae is the largest Neotropical orchid subtribe encompassing >5100 species that are mainly dipteran-pollinated. Various pollination syndromes, targeting hump-backed flies (Phoridae), fungal gnats (Sciaridae), and... more
Pleurothallidinae is the largest Neotropical orchid subtribe encompassing >5100 species that are mainly dipteran-pollinated. Various pollination syndromes, targeting hump-backed flies (Phoridae), fungal gnats (Sciaridae), and vinegar flies (Drosophilidae) have been documented in detail for Acianthera, Dracula, Lepanthes, Octomeria, Pleurothallis, and Specklinia, all belonging to different clades. Among them, the highly diverse genus Lepanthes, including about 25% of the species of the Pleurothallidinae, is most closely related to Anathallis, Draconanthes, Frondaria, Lankesteriana, Lepanthopsis, Trichosalpinx, and Zootrophion. Members of this “Lepanthes clade” display high floral divergence and are likely adapted to different pollinators . However, only two pollination studies have been published for the group: one for Lepanthes, pollinated by Bradysia (fungal gnats) and another for Trichosalpinx, pollinated by Forcipomyia (biting midges). Floral traits present in Trichosalpinx, such as purple flowers and a mobile, pubescent lip, evolved to accommodate pollination by biting midges. These traits are also found in other plant species pollinated by biting midges such as Bulbophyllum, Ceropegia spp. (Asclepiadaceae), and Theobroma cacao (Malvaceae). Because some members of the Lepanthes clade exhibit similar floral traits, we hypothesize that pollination by biting midges evolved in these orchids as well. In this study, we discuss the micromorphological and histochemical features of the flowers among some of the members of the Lepanthes clade in order to test the hypothesis on floral convergence in plants pollinated by biting midges and also which other pollination strategies can be inferred from flower anatomy in the sister genera. Based on histochemistry, LM, and SEM we found similar floral secretions such as carbohydrates, proteins, and lipids in different organs of Anathallis, Lankesteriana, and Trichosalpinx, supporting the hypothesis of floral parallelism in these genera. Lepanthopsis with a papillose lip and secretory glenion and Zootrophion with closing flowers and verrucose-papillose inner surface of sepals might employ different pollination systems. This study provides additional micromorphological and histochemical data to support future pollination studies of other members of the Lepanthes clade.
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... Salvator NTORE1 ?*, Elmar ROBBRECHT2, Erik SMETS1 et Steven DESSEIN1 laboratory of Plant Systematics, Institute of Botany and Microbiology ... Mts), Dowsett-Lemaire 682 (Misuku Hills), Gereau 3983 (Ludewa), Gereau 4200 (Mbeya)]... more
... Salvator NTORE1 ?*, Elmar ROBBRECHT2, Erik SMETS1 et Steven DESSEIN1 laboratory of Plant Systematics, Institute of Botany and Microbiology ... Mts), Dowsett-Lemaire 682 (Misuku Hills), Gereau 3983 (Ludewa), Gereau 4200 (Mbeya)] montrent uniquement des domaties en ...
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The chrome azurol-S test, which is a chemical spot-test for Al accumulation in wood, was applied to 443 wood samples of members of the Rubiaceae. A positive reaction was found in 103 specimens. Comparison of the results with earlier... more
The chrome azurol-S test, which is a chemical spot-test for Al accumulation in wood, was applied to 443 wood samples of members of the Rubiaceae. A positive reaction was found in 103 specimens. Comparison of the results with earlier analyses of leaves of Rubiaceae shows that Al accumulation occurs more frequently in leaves than in wood. The strongest Al accumulators occur in the neotropical genera Psychotria subg. Heteropsychotria, Coussarea, Faramea, and Rudgea. The distribution of Al accumulators is discussed in view of recent tribal and subfamilial classification of the Rubiaceae. The major conclusion is that Al accumulation is almost limited to the subfamily Rubioideae. Within the Rubioideae, however, not all tribes show the character, especially the predominantly herbaceous Anthospermeae, Paederieae, Rubieae, and Spermacoceae. Al accumulation in the Urophylleae, Pauridiantheae, Craterispermeae, and Knoxieae supports earlier associations of these tribes with the Rubioideae.
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Roos, M.C., Berendsohn, W.G., Dessein, S., Hamann, T., Hoffmann, N., Hovenkamp, P., Janssen, T., Kirkup, D., Kok, R. de, Sierra, S.E.C., Smets, ., Webb, ., Welzen, .C. van (2011): e-Flora Malesiana: state of the art and perspectives.... more
Roos, M.C., Berendsohn, W.G., Dessein, S., Hamann, T., Hoffmann, N., Hovenkamp, P., Janssen, T., Kirkup, D., Kok, R. de, Sierra, S.E.C., Smets, ., Webb, ., Welzen, .C. van (2011): e-Flora Malesiana: state of the art and perspectives. Gardens' Bulletin Singapore 63: 189-195, DOI: http://doi.org/10.5281/zenodo.5806354
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... B-1860 Meise, Belgium; email: el-mar.robbrecht@br.fgov.be) & E. Smets (Laboratory of Plant Systematics, Institute of Botany and Microbiology, KULeuven, Kasteelpark Arenberg 31, B-3001 Leu-yen, Belgium; email:... more
... B-1860 Meise, Belgium; email: el-mar.robbrecht@br.fgov.be) & E. Smets (Laboratory of Plant Systematics, Institute of Botany and Microbiology, KULeuven, Kasteelpark Arenberg 31, B-3001 Leu-yen, Belgium; email: erik.smets@bio.kuleuven ... 9. Longitudinal section of floral bud. ...
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The goal of this work is to study the evolution and the degree of horizontal gene transfer (HGT) within rhizobial genera of both Alpha- (Mesorhizobium, Rhizobium) and Beta (Burkholderia) Proteobacteria, originating from South African... more
The goal of this work is to study the evolution and the degree of horizontal gene transfer (HGT) within rhizobial genera of both Alpha- (Mesorhizobium, Rhizobium) and Beta (Burkholderia) Proteobacteria, originating from South African Fynbos legumes. By using a phylogenetic approach and comparing multiple chromosomal and symbiosis genes, we revealed conclusive evidence of high degrees of horizontal transfer of nodulation genes among closely related species of both groups of rhizobia, but also among species with distant genetic backgrounds (Rhizobium and Mesorhizobium), underscoring the importance of lateral transfer of symbiosis traits as an important evolutionary force among rhizobia of the Cape Fynbos biome. The extensive exchange of symbiosis genes in the Fynbos is in contrast with a lack of significant events of HGT among Burkholderia symbionts from the South American Cerrado and Caatinga biome. Furthermore, homologous recombination among selected housekeeping genes had a substan...
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Research Interests: Plant Biology, Pheromones, Ecology, Pollination, Drosophila, and 5 moreFemale, Animals, Male, Orchidaceae, and Species Specificity
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... D. coerulea Gardn. Brazil. E of Rio de Janeiro, Pedra do Sino, Kirkbride, Emmerick and Wagner 1722 (BR 810112). D. cordigera Mart. and Zucc. ex Schult. ... ex Schult. and Schult. Brazil. Minas Gerais, Widgren 1034 (BR 810079). D.... more
... D. coerulea Gardn. Brazil. E of Rio de Janeiro, Pedra do Sino, Kirkbride, Emmerick and Wagner 1722 (BR 810112). D. cordigera Mart. and Zucc. ex Schult. ... ex Schult. and Schult. Brazil. Minas Gerais, Widgren 1034 (BR 810079). D. oenanthoides Mart. and Zucc. ex Schult. ...
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Research Interests: Plant Biology, Biology, Climate, Medicine, Phylogeny, and 5 moreAluminum, Plant, Angiosperms, Ecosystem, and Species Specificity
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The morphology and anatomy of the African monospecific genus Colletoecema E. Petit (Rubiaceae) is documented and illustrated (including wood anatomy, pollen morphology, gynoecial and exotestal structure). Morphological and anatomical... more
The morphology and anatomy of the African monospecific genus Colletoecema E. Petit (Rubiaceae) is documented and illustrated (including wood anatomy, pollen morphology, gynoecial and exotestal structure). Morphological and anatomical comparison shows that Colletoecema differs in many aspects from the Psychotrieae (e.g., wood anatomy, seed structure). Consequently, the genus' provisional position in the Psychotrieae cannot be maintained. Morindeae, the second tribe Colletoecema has been associated with, has a different gynoecial structure. The oily endosperm and large embryo of Colletoecema is found in several genera that often were or still are included in the Psychotrieae or Morindeae (Trichostachys, Saldinia, Ronabea, and Lasianthus). However, they differ in several other aspects, which makes a close relationship doubtful. Colletoecema exhibits a unique combination of characters including axillary inflorescences, banded parenchyma in the wood, ovules attached around the middle of the septum, bilocular pyrenes, seeds with oily endosperm and large embryo, and verrucate exotestal thickenings, not encountered elsewhere in the Rubioideae. A cladistic analysis based on nucleotide sequence variation in the rps16 intron (chloroplast DNA) confirms that Colletoecema is related neither to Psychotrieae nor to Morindeae. Colletoecema appears as a sister genus of Ophiorrhiza in a weakly supported clade among the basalmost clades of the subfamily Rubioideae, but there is very little morphological support for this relationship.Key words: anatomy, chloroplast DNA, cladistics, morphology, Psychotrieae, Rubioideae.
Research Interests: Botany and Plant Biology
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... Ecology of Rubiaceae on central African inselbergs. Degreef, Jérôme; Parmentier, I.; Banak Ngok, Ludovic; Robbrecht, Elmar (in: Taxonomy and ecology of African plants, their conservation and sustainable use / Ghazanfar, SA [edit.];... more
... Ecology of Rubiaceae on central African inselbergs. Degreef, Jérôme; Parmentier, I.; Banak Ngok, Ludovic; Robbrecht, Elmar (in: Taxonomy and ecology of African plants, their conservation and sustainable use / Ghazanfar, SA [edit.]; 2006). ...
Angiosperms with simple vessel perforations have evolved many times independently of species having scalariform perforations, but detailed studies to understand why these transitions in wood evolution have happened are lacking. We focus... more
Angiosperms with simple vessel perforations have evolved many times independently of species having scalariform perforations, but detailed studies to understand why these transitions in wood evolution have happened are lacking. We focus on the striking difference in wood anatomy between two closely related genera of Adoxaceae, Viburnum and Sambucus, and link the anatomical divergence with climatic and physiological insights. After performing wood anatomical observations, we used a molecular phylogenetic framework to estimate divergence times for 127 Adoxaceae species. The conditions under which the genera diversified were estimated using ancestral area reconstruction and optimization of ancestral climates, and xylem-specific conductivity measurements were performed. Viburnum, characterized by scalariform vessel perforations (ancestral), diversified earlier than Sambucus, having simple perforations (derived). Ancestral climate reconstruction analyses point to cold temperate preferenc...
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The floral development and vascular anatomy of Nitraria retusa were investigated in order to understand its characteristic androecium of 15 stamens and to clarify the systematic position of the genus relative to Zygophyllaceae. Sepals... more
The floral development and vascular anatomy of Nitraria retusa were investigated in order to understand its characteristic androecium of 15 stamens and to clarify the systematic position of the genus relative to Zygophyllaceae. Sepals arise in a helical sequence and are relatively small at maturity. Petals are initiated almost simultaneously or in a rapid helical sequence. Five stamen primordia arise opposite the sepals. Next, two other antesepalous primordia are incepted centrifugally to the first primordia on the remaining receptacular surface. The outer stamens tend to be squeezed between the petals and upper stamens and appear to make up an antepetalous whorl of stamens. Three carpels arise from a low ringwall and grow into a hairy trilocular pistil. In each locule a single pendulous ovule is present. Disclike nectarial tissue is initiated in pits between the stamens and petals. Long trichomes develop on its surface. It is concluded that the androecium is linked with a haplostemonous condition because the stamens of each triplet develop on strictly localized sectors. The distinction between stamens arising on complex primordia and the inception of three independent units is explained by the "principle of variable proportions." The vasculature also tends to confirm that the outer stamen pairs belong to antesepalous triplets.
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Balsaminaceae consist of two genera, the monospecific Hydrocera and its species-rich sister Impatiens. Although both genera are seemingly rather similar in overall appearance, they differ in ecology, distribution range, habitat preference... more
Balsaminaceae consist of two genera, the monospecific Hydrocera and its species-rich sister Impatiens. Although both genera are seemingly rather similar in overall appearance, they differ in ecology, distribution range, habitat preference and morphology. Because morphological support for the current molecular phylogenetic hypothesis of Impatiens is low, a developmental study is necessary in order to obtain better insights into the evolutionary history of the family. Therefore, the floral development of H. triflora and I. omeiana was investigated, representing the most early-diverged lineage of Impatiens, and the observations were compared with the literature. Flowers at all developmental stages were examined using scanning electron microscopy and light microscopy. In Hydrocera, two whorls of five free perianth primordia develop into a less zygomorphic perianth compared with its sister genus. The androecial cap originates from five individual stamen primordia. Post-genital fusion of ...
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Pollen descriptions, based on LM and SEM observations, are provided for the Pentas complex, an African alliance within the Hedyotideae–Spermacoceae alliance, which includes the genera Pentas, Otomeria, Batopedina, Parapentas, and... more
Pollen descriptions, based on LM and SEM observations, are provided for the Pentas complex, an African alliance within the Hedyotideae–Spermacoceae alliance, which includes the genera Pentas, Otomeria, Batopedina, Parapentas, and Chamaepentas. The close relationship among these genera is confirmed by pollen morphological data. The observed variation in pollen character states agrees well with the existing genera and subgenera. The combination
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Three genera in the Rubiaceae (Pavetta, Psychotria and Sericanthe) harbour bacterial endosymbionts within leaf nodules or galls. The present paper identifies the bacterial endophytes in three leaf-nodulating Pavetta species. In order to... more
Three genera in the Rubiaceae (Pavetta, Psychotria and Sericanthe) harbour bacterial endosymbionts within leaf nodules or galls. The present paper identifies the bacterial endophytes in three leaf-nodulating Pavetta species. In order to reveal their identity and assess their phylogenetic position, 16S rRNA, recA and gyrB genes were sequenced from an extensive sampling of Burkholderia strains. This multigene approach results in a robust phylogeny, which places the bacterial endosymbionts of Pavetta at two distinct positions within the genus Burkholderia (class Betaproteobacteria), suggesting that leaf-nodulating endosymbionts within Pavetta have different origins. The endophytes of nodulated Psychotria species were recognized as the closest relatives to the Pavetta endosymbionts. Our results suggest that the endosymbionts of Pavetta represent novel species, which can be classified as ‘Candidatus Burkholderia hispidae’, ‘Candidatus Burkholderia rigidae’ and ‘Candidatus Burkholderia sc...
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ABSTRACTLeaf-nodulated plants are colonized by vertically inherited bacterial endosymbionts, which maintain symbioses throughout host generations. The permanent character of the interaction implies phylogenetic congruence between the host... more
ABSTRACTLeaf-nodulated plants are colonized by vertically inherited bacterial endosymbionts, which maintain symbioses throughout host generations. The permanent character of the interaction implies phylogenetic congruence between the host and the endosymbiont. However, the present population genetic study ofPsychotria leptophyllaprovides evidence for a mixed symbiont transmission involving both vertical inheritance and horizontal transfers from the environment.