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| Registros recuperados: 41 | |
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| Lens, F.; Schönenberger, J.; Baas, P.; Jansen, S.; Smets, E.. |
| The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However, when pedomorphic character states are coded as inapplicable, the combined bootstrap topology results in an increase of resolution and support at most deeper nodes compared with the molecular analyses. This suggests that phylogenetic information from the limited number of morphological characters is not completely swamped by an overwhelming amount of molecular data. Based on the morphology of vessels and fibers, and the distribution of axial parenchyma, two... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Anatomy; Phylogeny; Ericales; 42.48. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/422235 |
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| Lens, F.; Jansen, S.; Huysmans, S.; Robbrecht, E.; Smets, E.. |
| The Vanguerieae is a large tribe of the subfamily Ixoroideae (Rubiaceae) and consists of about 500 species in 27 genera. This study gives a detailed pollen morphological description of 30 species from 16 genera, based on light microscopy and scanning electron microscopy. The Vanguerieae are considered to be stenopalynous, although there is some evidence to question this. First, there is a difference in sexine types that clearly de® nes Keetia and Psydrax ( both reticulate) , and Canthium and Vanguerieae (both perforate with very small perforations) from the other Vanguerieae investigated. Second, pollen grains corroborate the subgeneric delimitations of Canthium sensu Bridson. Pollen morphologically the tribe is characterised by ( 1) the shape of the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Vanguereae; Ixoroideae; Rubiaceae; Pollen; Morphological variation; Stenopalynous; 42.58. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/423771 |
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| Lens, F.; Luteyn, J.L.; Smets, E.; Jansen, S.. |
| The ecological wood anatomy of 128 vaccinioid wood samples (including 115 species, 35 genera), collected between 39°S and 60°N latitude and 10 m to 3400 m altitude is studied. Several wood anatomical features within the subfamily, viz. tangential vessel diameter, average length of tracheary elements, height of multiseriate rays, and presence of prismatic crystals are negatively correlated with increasing latitude, while vessel density and helical thickenings show a positive correlation with increasing latitude. Similar latitudinal trends are found within the genus Vaccinium (31 species studied). The correlation between various wood anatomical features and latitude is surprisingly high despite the fact that most tropical species grow in montane regions,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Altitude; Ecological and functional wood anatomy; Ericaceae; Latitude; Vaccinioideae; Vaccinium; 42.58. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/424624 |
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| Jansen, S.; Sano, Y.; Choat, B.; Rabaey, D.; Lens, F.; Dute, R.R.. |
| The micromorphology of pits in tracheary elements was examined in 35 species representing 29 genera of Rosaceae and related families to evaluate the assumption that angiosperm pits are largely invariant. In most Rosaceae, pit membranes between fibers and tracheids frequently appear to have amorphous thickenings with an irregular distribution. Although these structures are toruslike under the light microscope, observations by electron microscopy illustrate that they represent ‘‘pseudotori’’ or plasmodesmata-associated thickenings. These thickenings frequently extend from the periphery of the pit membrane and form a cap-like, hollow structure. Pseudotori are occasionally found in few Elaeagnaceae and Rhamnaceae and appear to be related to species with... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Fiber; Pit; Pit membrane; Pseudotorus; Rosaceae; Rosales; Torus; Tracheid; 42.58. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/423505 |
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| Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.. |
| Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the distribution and morphology of pit membrane thickenings in 69 species and 23 genera within Oleaceae using light and electron microscopy. Torus-bearing pit membranes are confirmed for Osmanthus, and new records are reported for Chionanthus retusa, Picconia azorica, and P. excelsa, but not for the other species studied of Chionanthus. This infrageneric variation suggests that tori represent a plastic feature that has evolved more than once within the family as the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Electron microscopy; Pit aperture; Pit membrane; Plasmodesmata; Pseudo-torus; Torus; Tracheid; Vessel element; 42.56. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/429536 |
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| Lens, F.; Smets, E.; Melzer, S.. |
| The soc1 ful double mutant of A. thaliana produced substantial secondary growth throughout all aboveground stems, whereas in the Col accession only a few cell layers of wood were produced at the base of old stems. This increased wood formation may be linked to inactivation of the flowering time genes SOC1 and FUL (Melzer et al., 2008). These two genes could play a crucial regulatory role in triggering genetic mechanisms that lead to insular woodiness outside A. thaliana, and this ‘simple’ two-gene loss could explain why many nonrelated herbaceous families have independently evolved into woody insular lineages throughout the world. However, SOC1 and FUL might not be the only suppressors of cambium formation; other upstream, downstream or parallel-acting... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Stem anatomy; Arabidopsis thaliana; Insular woodiness; Brassicaceae; Wood formation; 42.56. |
| Ano: 2012 |
URL: http://www.repository.naturalis.nl/record/429528 |
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| Lens, F.; Jansen, S.; Caris, P.; Serlet, L.; Smets, E.. |
| The wood structure of 78 species from 27 genera representing the woody primuloids (Maesaceae, Myrsinaceae, and Theophrastaceae) was investigated using light microscopy (LM) and scanning electron microscopy (SEM). Results indicated that the ray structure, the nature of mineral inclusions, and the occurrence of breakdown areas in rays can be used to separate the three primuloid families from each other. Within Ericales, the presence of exclusively multiseriate rays is synapomorphic for Myrsinaceae and Theophrastaceae, and the occurrence of breakdown areas in rays is synapomorphic for Myrsinaceae. Within Myrsinaceae, the wood structure of the mangrove genus Aegiceras differs because it has short vessel elements that are storied, non-septate fibers, a... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Primuloids; Ericales s.l.; Maesaceae; Myrsinaceae; Theophrastaceae; Wood anatomy; Comparison; Light microscopy; Scanning electron microscopy. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407307 |
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| Lens, F.; Gasson, P.; Smets, E.; Jansen, S.. |
| The wood anatomy of 16 of the 37 genera within the epacrids (Styphelioideae, Ericaceae s.l.) is investigated by light and scanning electron microscopy. Several features in the secondary xylem occur consistently at the tribal level: arrangement of vessel‐ray pits, distribution of axial parenchyma, ray width, and the presence and location of crystals. The primitive nature of Prionoteae and Archerieae is supported by the presence of scalariform perforation plates with many bars and scalariform to opposite vessel pitting. The wood structure of Oligarrheneae is similar to that of Styphelieae, but the very narrow vessel elements, exclusively uniseriate rays and the lack of prismatic crystals in Oligarrheneae distinguish these two tribes. The secondary xylem of... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ecological wood anatomy; Epacrids; Ericaceae s.l.; Styphelioideae; Systematic wood anatomy; 42.56. |
| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/431740 |
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| Melzer, S.; Lens, F.; Gennen, J.; Vanneste, S.; Rohde , A.; Beeckman, T.. |
| Plants have evolved annual and perennial life forms as alternative strategies to adapt reproduction and survival to environmental constraints. In isolated situations, such as islands, woody perennials have evolved repeatedly from annual ancestors1. Although the molecular basis of the rapid evolution of insular woodiness is unknown, the molecular difference between perennials and annuals might be rather small, and a change between these life strategies might not require major genetic innovations2,3. Developmental regulators can strongly affect evolutionary variation4 and genes involved in meristem transitions are good candidates for a switch in growth habit. We found that the MADS box proteins SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and FRUITFULL... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Flowering-time; Meristem determinacy; Growth form; Arabidopsis thaliana; Insular woodiness; Secondary growth; Annual life forms; 42.56. |
| Ano: 2008 |
URL: http://www.repository.naturalis.nl/record/429531 |
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| Lens, F.; Jansen, S.; Robbrecht, E.; Smets, E.. |
| The Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Vanguereae; Rubiaceae; Systematic wood anatomy; Geofrutex; 42.58. |
| Ano: 2000 |
URL: http://www.repository.naturalis.nl/record/423793 |
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| Jansen, S.; Lens, F.; Ntore, S.; Piesschaert, F.; Robbrechf, E.; Smets, E.. |
| The secondary xylem of Craterispermeae, Coussareeae, Morindeae s.str., Prismatomerideae, Pauridiantheae, Urophylleae, and Triainolepideae (Rubiaceae, Rubioideae) is described and illustrated in detail. Genera that were previously placed in the Morindeae or Psychotrieae such as Damnacanthus, Lasianthus, Saldinia, and Trichosfachys are also included. Wood anatomical characters are compared with recent phylogenetic insights into the study group on the basis of molecular data. The observations demonstrate that the delimitation and separation of several taxa from the former Coussareeae/Morindeae/Prismatomerideae/Psychotrieae aggregate is supported by wood anatomical data. The Coussareeae can be distinguished from the other Rubioideae by their scanty parenchyma,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Rubiaceae; Rubioideae; Systematic wood anatomy; 42.58. |
| Ano: 2001 |
URL: http://www.repository.naturalis.nl/record/421859 |
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| Lens, F.; Smets, E.; Jansen, S.. |
| The wood anatomical structure of 11 out of 13 genera from four tribes of the Vaccinioideae, namely Andromedeae s.s., Gaultherieae, Lyonieae and Oxydendreae (Ericaceae s.l.), is described using light and scanning electron microscopy. Several features of the secondary xylem support the tribal classification based on molecular data: arrangement of vessel-ray pitting, height of multiseriate rays and the shape of the body ray cells. Oxydendreae are clearly defined from the other representatives by various wood anatomical features. Gaultherieae can be distinguished from Lyonieae by differences in vessel perforation plates, vessel-ray pitting, height and structure of multiseriate rays, and occurrence of prismatic crystals, but the wood of Andromedeae s.s. is... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Comparative wood anatomy; Andromedeae; Gaultherieae; Lyonieae; Oxydendreae; Vaccinioideae; Ericaceae; Andromedeae sensu Stevens; Pith structure; 42.58. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/424620 |
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| Lens, F.; Cooper, L.; Gandolfo, M.A.; Groover, A.; Jaiswal, P.; Lachenbruch, B.; Spicer, R.; Staton, M.E.; Stevenson, D.W.; Walls, R.L.; Wegrzyn, J.. |
| The Wood Ontology project will provide a structured vocabulary and database resource that will be valuable for all scientists, including the IAWA community. To maximizethe utility of the resource and analyses it empowers, it is important for researchers to adopt the use of the ontology terms in the collection and dissemination of their data. The PO website (www.plantontology.org) is the main portal for the Plant Ontology, and presents the current version. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Plant Ontology; Wood anatomy and development; Plant morphology; Structured vocabulary; Database resource; 42.40. |
| Ano: 2012 |
URL: http://www.repository.naturalis.nl/record/429515 |
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| Registros recuperados: 41 | |
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