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1.
Plant Biol (Stuttg) ; 21(1): 157-166, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30134002

RESUMEN

Pollen/ovule (P/O) ratios are often used as proxy for breeding systems. Here, we investigate the relations between breeding systems and P/O ratios, pollination syndromes, life history and climate zone in Balsaminaceae. We conducted controlled breeding system experiments (autonomous and active self-pollination and outcrossing tests) for 65 Balsaminaceae species, analysed pollen grain and ovule numbers and evaluated the results in combination with data on pollination syndrome, life history and climate zone on a phylogenetic basis. Based on fruit set, we assigned three breeding systems: autogamy, self-compatibility and self-incompatibility. Self-pollination led to lower fruit set than outcrossing. We neither found significant P/O differences between breeding systems nor between pollination syndromes. However, the numbers of pollen grains and ovules per flower were significantly lower in autogamous species, but pollen grain and ovule numbers did not differ between most pollination syndromes. Finally, we found no relation between breeding system and climate zone, but a relation between climate zone and life history. In Balsaminaceae reproductive traits can change under resource or pollinator limitation, leading to the evolution of autogamy, but are evolutionary rather constant and not under strong selection pressure by pollinator guild and geographic range changes. Colonisation of temperate regions, however, is correlated with transitions towards annual life history. Pollen/ovule-ratios, commonly accepted as good indicators of breeding system, have a low predictive value in Balsaminaceae. In the absence of experimental data on breeding system, additional floral traits (overall pollen grain and ovule number, traits of floral morphology) may be used as proxies.


Asunto(s)
Balsaminaceae/fisiología , Clima , Óvulo Vegetal/fisiología , Fitomejoramiento , Polen/fisiología , Polinización/fisiología , Filogenia , Análisis de Regresión
2.
J Microsc ; 256(3): 226-30, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25204567

RESUMEN

Internal sample conductivity in scanning electron microscopy can be a valuable alternative to metal coating. Proton conductivity may be used for this purpose. Many solid materials with active hydrogen atoms, such as hydrogen- and ammonium-salts, organic acids, and even ice, are protonic conductors or semiconductors. Here we present a method to generate proton conductivity in dry biological materials. A simple treatment with hydrogen chloride gas or hydrochloric acid vapour for a few minutes provides sufficient conductivity for many samples. After a removal of excess hydrogen chloride vapour with a vacuum desiccator, the objects may be examined in the SEM without metal coating. The use of internally conductive samples extends the range of easy-to-perform SEM preparation techniques. It is advantageous for material contrast imaging of uncoated samples, and it can be used in combination with metal coating to enhance conductivity on difficult samples with complex overlapping surfaces, where simple metal coating does not reliably eliminate charging problems.


Asunto(s)
Gases/química , Microscopía Electrónica de Rastreo/métodos , Desecación/métodos , Ácido Clorhídrico/química , Metales/química , Protones
3.
Plant Biol (Stuttg) ; 8(1): 120-42, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16435276

RESUMEN

Floral morphology, distribution, and flower visitors for 60 taxa of Nasa are investigated and compared to molecular trees inferred both from a combined marker analysis (ITS1 and trnL (UAA)) and from a single marker (ITS1). Flowers conform to two different floral types: Firstly, "tilt-revolver flowers", with spreading to reflexed, white to yellow petals and small, brightly coloured floral scales contrasting with the petals and firmly enclosing the nectar (Saccatae and Carunculatae); secondly, "funnel-revolver flowers", with half-erect to erect, orange to red petals and floral scales not contrasting with the petals, or enclosed in the corolla, and nectar freely accessible by funnel-shaped floral scales ( Alatae, Grandiflorae, and N. venezuelensis species group). Phylogenetic analysis shows that "tilt-revolver flowers" represent the plesiomorphic condition by outgroup comparison. The two groups with tilt-revolver flowers in Nasa are not monophyletic ( Saccatae are paraphyletic, Carunculatae are polyphyletic). Most Saccatae fall into two monophyletic assemblages, the N. poissoniana species group and the N. triphylla species group. The remainder of Saccatae group either with Grandiflorae ( N. insignis species group) or with Alatae ( N. laxa species group). The clades retrieved in the molecular analysis contradict the traditional classification, but are congruent with vegetative morphology, details of the flower morphology, and biogeography. "Funnel-revolver flowers" represent the derived condition, but molecular data suggest a convergent development (at least twice independently), since the corresponding species do not constitute a monophyletic group. "Tilt-revolver flowers" are visited and pollinated by bees (especially Colletidae), whereas "funnel-revolver flowers" are mostly visited by hummingbirds. The transition from melittophily to ornithophily may have been the license for the colonization of, and the diversification in, both cloud forest and high Andean habitats.


Asunto(s)
Evolución Biológica , Flores/anatomía & histología , Magnoliopsida/anatomía & histología , Animales , Abejas/fisiología , Aves/fisiología , Flores/fisiología , Magnoliopsida/genética , Magnoliopsida/fisiología , Filogenia , Hojas de la Planta/anatomía & histología
4.
Am J Bot ; 87(8): 1202-10, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10948006

RESUMEN

A screening for iridoid compounds of 78 of 315 species from all major groups in Gronoviaceae and Loasaceae has been carried out. The results were compared to the systematic concepts in the family and distribution and ecology of the taxa. Iridoids are present in at least some species of all genera screened. Some simple, monomeric compounds (e.g., loganin, sweroside) are found in all major groups of the two families and represent the basic iridoid inventory. Other compounds are restricted to certain taxonomic groups: nine-carbon iridoids (e.g., deutzioside) are restricted to Mentzelia (Loasaceae subfam. Mentzelioideae), hetero-oligomeric iridoids (e.g., tricoloroside methyl ester, acerifolioside) are restricted to two small groups in Loasa (Loasa ser. Macrospermae and ser. Floribundae, Loasaceae subfam. Loasoideae), and oleosides (e.g., 10-hydroxyoleoside dimethyl ester) are restricted to the large genus Caiophora sensu Weigend). The distribution of certain iridoid compounds thus confirms some of the generic limits. Iridoid phytochemistry does not correlate with systematic entities above the generic level nor does it in any way correlate with the morphological evolution of taxa. Conversely, the amount and complexity of iridoid compounds present in taxa correlate positively with the aridity of their habitat and the extent of mammalian herbivore pressure.

5.
Phytochemistry ; 49(1): 131-5, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9745765

RESUMEN

In the course of preliminary chemotaxonomic studies on Loasaceae from South and Central America, 30 species from 6 genera were screened by chromatographic means. From the aerial parts of Loasa acerifolia Dombey, the novel trimeric and dimeric iridoid glucosides acerifolioside and tricoloroside methyl ester, consisting of loganin and secoxyloganin moieties, were isolated. The structures were primarily elucidated by NMR spectroscopy. Loganin, loganic acid, rutin, scopoletin and chlorogenic acid were identified by cochromatography with reference compounds.


Asunto(s)
Glicósidos/química , Plantas Medicinales/clasificación , Piranos/química , América Central , Glicósidos/aislamiento & purificación , Medicina Tradicional , Conformación Molecular , Resonancia Magnética Nuclear Biomolecular , Hojas de la Planta , Plantas Medicinales/química , Piranos/aislamiento & purificación , Semillas , América del Sur , Espectrometría de Masa Bombardeada por Átomos Veloces
6.
Beitr Gerichtl Med ; 49: 325-31, 1991.
Artículo en Alemán | MEDLINE | ID: mdl-1811517

RESUMEN

Urine samples of 120 heroin-addicted probands who had to take part in urinanalysis tests were analysed during a 26 months' period. Up to 7 substances (morphine/diamorphie, codeine, cocain, LSD, cannabinoides, barbiturates and amphetamines) were tested. The results were compared to the results of a group of 177 cannabies-smokers. The purpose of this study was to find out in how far urinanalysis tests can change drug-consuming behaviour. More than 80% of the cannabis-smokers showed evidently a decrease of THC-positive urine samples at the end of the investigation period. Only about 13% had positive samples during the whole period. 12 out of 120 heroin-addicted probands (= 10%) had morphine-positive urine samples at the beginning of investigations. For 104 out of 1423 tested samples (46 probands) an unmistakable distinction between morphine/diamorphine- or codeine-intake was not possible because the concentrations found were too low. About 20% of the samples indicated a shift to a substitutional used drug like codeine. Further more a slightly significant increase of cannabis-intake was to be observed.


Asunto(s)
Dependencia de Heroína/rehabilitación , Heroína/farmacocinética , Drogas Ilícitas/farmacocinética , Detección de Abuso de Sustancias/métodos , Estudios de Seguimiento , Dependencia de Heroína/orina , Humanos
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