Photoprotection mechanisms in desiccation tolerance of two Hymenophyllaceae Family (Pteridophyte) species contrasting in their vertical distribution :morpho-anatomical variations of fronds and structural and physiological changes at the chloroplasts level

Mostrar el registro sencillo del ítem

Profesor Guia
Bravo Ramírez, León Aloys
Profesor Guia
Corcuera Pérez, Luis Julián
Autor y otros
Flores Bavestrello, Alejandra del Pilar
Fecha de carga del item
2017-05-26T19:08:55Z
Fecha de disponibilidad
2017-05-26T19:08:55Z
Fecha de publicacion
2016
Numero sistema Aleph
000228281
URI
http://repositorio.udec.cl/handle/11594/2114
Descripcion: corresponde a la nota de tesis
Doctor en Ciencias Biológicas, área de especialización botánica Universidad de Concepción 2016
Resumen
Hymenophyllum dentatum Cav. and Hymenoglossum cruentum C. Presl (Pteridophyta: Hymenophyllaceae) are desiccation tolerant ferns. They are poikilohydric epiphytes, with fronds composed by a single layer of cells and without true mesophyll cells and stomata. In Chile, these species belong to the temperate rain forest, and they usually inhabit shady and humid environments. However, as epiphytes, their vertical distribution varies along the trunk of the host plant. Some species inhabit drier sides with higher irradiance, as H. dentatum Cav., while others inhabit wetter and shadier sides. The aim of this work was to characterize the morphological variations in H. dentatum Cav. and H. cruentum C.Presl fronds during hydrated, desiccated, and rehydrated states. Both species were subjected to desiccation and rehydration kinetics to analyze the frond morphological variations in different hydration states by a scanning electron microscope. It was observed in both species, a change in the shape of desiccated cells from convex to concave. Fully hydrated fronds showed cells with an irregular polygon shape; a disorganized disposition of cells, and different sizes of them. Glandular multicellular hairs with a distal secretory cell were observed only in H. dentatum Cav. throughout the vascular system of the lamina. We conclude that, although cells decreased their sizes, there was not cells collapse in the desiccated state of both species, which helps to their fast recovery and functioning. The presence of wax glands in H. dentatum Cav., appears to be a different strategy to cope with desiccation tolerance in the higher zones of the host trunk.
idioma
eng
Editor
Universidad de Concepción (Chile). Facultad de Ciencias Biológicas. |b Programa de Doctorado en Ciencias Biológicas. Area Biología Celular y Molecular
Materias
Desecación
Materias
Cloroplastos
Materias
Fotosíntesis.
Titulo
Photoprotection mechanisms in desiccation tolerance of two Hymenophyllaceae Family (Pteridophyte) species contrasting in their vertical distribution :morpho-anatomical variations of fronds and structural and physiological changes at the chloroplasts level
Otro titulo: es un titulo alternativo, corresponden a las variantes del titulo propiamente tal
Mecanismos fotoprotectores en la tolerancia a la desecación en dos especies de la Familia Hymenophyllaceae (Pteridophyta) contrastantes en su distribución vertical: variación morfo-anatómica de frondes y cambios estructurales y fisiológicos a nivel de cloroplastos
Tipo de documento
Thesis


Ficheros en el ítem

Este ítem aparece en la(s) siguiente(s) colección(es)

Mostrar el registro sencillo del ítem