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1.
Ann Bot ; 96(7): 1247-64, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16216820

RESUMEN

BACKGROUND AND AIMS: The generic delimitations of Ficinia and Isolepis, sister genera in the Cypereae, are blurred. Typical Ficinia flowers have a lobed gynophore, which envelops the base of the nutlet, whereas in Isolepis the character is considered to be absent. Some former species of Isolepis, lacking the gynophore, were recently included in Ficinia. The floral ontogeny of representative taxa in Ficinia and Isolepis were investigated with the aim of evaluating the origin and nature of the gynophore in the Cypereae. METHODS: The spikelet and floral ontogeny in inflorescences collected in the field was investigated using scanning electron microscopy (SEM) and light microscopy (LM). KEY RESULTS: SEM images of Isolepis setacea and I. antarctica, Ficinia brevifolia, F. minutiflora, F. zeyheri and F. gracilis, and LM sections of F. radiata, show that the gynoecium in Ficinia is elevated above the flower receptacle by the development of a hypogynous stalk. From its apex, a (often three-)lobed cup is formed, which envelopes the basal part of the later nutlet. In developing flowers of I. antarctica, a rudimentary hypogynous stalk appears. In I. setacea, rudiments of a hypogynous stalk can be observed at maturity. In F. radiata and F. zeyheri, intralocular hairs are present in the micropylar zone. At the surface of developing gynoecia in flowers of F. gracilis, star-shaped cuticular structures appear which disappear again at maturity. CONCLUSIONS: The overall floral ontogeny of all species studied occurs following a typical scirpoid pattern, though no perianth primordia are formed. The gynophore in Ficinia originates as a hypogynous stalk, from which the typical gynophore lobes develop. The gynophore is not homologous with the perianth.


Asunto(s)
Cyperaceae/crecimiento & desarrollo , Copas de Floración/crecimiento & desarrollo , Flores/ultraestructura , Cyperaceae/clasificación , Copas de Floración/ultraestructura , Flores/crecimiento & desarrollo
2.
Ann Bot ; 95(7): 1199-209, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15788436

RESUMEN

BACKGROUND AND AIMS: Based on molecular phylogenetic analysis, it has been suggested recently that the Cyperaceae comprises only two subfamilies: the Mapanioideae and the Cyperoideae. In most flowers of the Cyperoideae, the whorl of inner stamens is reduced, resulting in tetracyclic flowers. In the more primitive (scirpoid) genera within the Cyperoideae, the perianth consists of two polysymmetric whorls, whereas the perianth parts in the more derived genera have been subject to modifications and/or reduction. Comparative studies of the many silky hairs of Eriophorum and of the eight bristles of Dulichium have given rise to much discussion about their homology. METHODS: The spikelet and floral ontogeny in freshly collected inflorescences was investigated using scanning electron microscopy. KEY RESULTS: Complete floral ontogenies are presented for Scirpus sylvaticus L., Eriophorum latifolium Hoppe and Dulichium arundinaceum (L.) Britton, with special reference to the perianth. The results in S. sylvaticus confirm the trimerous monocot-like organization of the flower. It is used as a model for floral development in Cyperoideae. In the early developmental stages, the androecium of E. latifolium is surrounded by a massive perigonial primordium, from which the many hair-like bristles originate. Consequently, the stamens develop among the hair primordia, more or less simultaneously. The hairs are arranged in whorls, which develop centripetally. The development of the perianth in D. arundinaceum starts with the formation of three initial perianth primordia opposite the stamens. Subsequently, two more abaxial bristle primordia, alternating with the stamens, originate simultaneously with the appearance of three adaxial bristle primordia in the zone where an adaxial inner perianth primordium is expected. CONCLUSIONS: The floral development in E. latifolium and D. arundinaceum can be considered as variations upon the scirpoid floral ontogenetic theme.


Asunto(s)
Cyperaceae/crecimiento & desarrollo , Flores/crecimiento & desarrollo , Cyperaceae/anatomía & histología , Cyperaceae/genética , Flores/anatomía & histología , Flores/genética , Especificidad de la Especie
3.
Plant Biol (Stuttg) ; 6(4): 498-505, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15248133

RESUMEN

The distribution of aluminium (Al) accumulation in the Ericales is surveyed, based on semi-quantitative tests of 114 species and literature data. Al accumulation mainly characterises the families Diapensiaceae, Pentaphylacaceae, Symplocaceae, Ternstroemiaceae, and Theaceae. Al accumulation is consistently present or absent in most families examined, but the character appears to be more variable in a few taxa (e.g., Lecythidaceae, Myrsinaceae). Although the interfamilial relationships within the Ericales require further research, the ability to accumulate high levels of Al appears to show considerable taxonomic significance. While the majority of Al accumulating Ericales includes woody, tropical plants, the feature is remarkably present in several herbaceous Diapensiaceae, which have a distribution in cold to temperate areas. The association of different mycorrhizae types with plant roots is suggested to play a role in the exclusion of high Al levels from the shoot.


Asunto(s)
Aluminio/farmacocinética , Magnoliopsida/metabolismo , Aluminio/toxicidad , Transporte Biológico Activo , Clima , Ecosistema , Magnoliopsida/clasificación , Filogenia , Especificidad de la Especie
4.
Soc Sci Med ; 42(6): 909-22, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8779003

RESUMEN

In Québec, recent political statements have strengthened the necessity to allocate resources according to regional population needs. A regional-provincial working group was set up to propose needs indicators in 8 different fields-or client-oriented programs-which subdivide the entire spectrum of health and social services in Québec. These programs include physical health, mental health, public health, functionally impaired elderly people, physical deficiency, intellectual deficiency, alcoholism and drug abuse and problems (abuse, neglect, delinquency) among young people and their families. The following paper summarizes the main proposals of the working group. Some comments are made on the definition of client-oriented programs, basic concepts, research questions and methodological approaches. Concrete examples are given in order to illustrate the type of data and methods used. Furthermore, the indicators selected for resource allocation (in each of the 8 client-oriented programs) are presented on a regional basis (n = 18) and introduced in a principal component analysis. Their variations are discussed and recommendations to facilitate their use and promote their development are made. Finally, the actual utilization of these indicators is reported.


Asunto(s)
Asignación de Recursos para la Atención de Salud/estadística & datos numéricos , Necesidades y Demandas de Servicios de Salud/estadística & datos numéricos , Regionalización , Servicio Social/estadística & datos numéricos , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Indicadores de Salud , Humanos , Lactante , Masculino , Área sin Atención Médica , Servicios de Salud Mental/provisión & distribución , Persona de Mediana Edad , Quebec/epidemiología
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