MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Morphological and ultraestructural studies on spores of Dennstaedtiaceae from the Paranaense Province
Autor/es:
GONZALO JAVIER MARQUEZ; MARTA ALICIA MORBELLI; AGUSTINA YAÑEZ
Lugar:
Salvador
Reunión:
Congreso; XIV IPC; 2016
Institución organizadora:
IPC
Resumen:
The spore morphology and wall ultrastructure of the Dennstaedtiaceae species from thePhytogeographic Paranaense Province were studied. It was based on herbarium specimens and fresh material, collected in field trips. Several techniques of fixation and differential stains applied and the observations were performed with light microscopy (LM) and scanning and transmission electron microscopes (SEM and TEM). As general characteristics, the spores of Dennstaedtiaceae species are of two kinds, monolete and trilete. Based on the diversity of sculptures observed and the predominant elements of the ornamentation, 7 morphological groups were recognized within the family: verrucose group, present in Dennstaedtia cicutaria, D. cornuta, D. dissecta, D. globulifera and D. obtusifolia; morphologic group with strands, present in Pteridium arachnoideum and Microlepia speluncae; baculate group, present in Blotiella lindeniana, regulate group, present in Paesia glandulosa; tuberculate group, present in Histiopteris incisa; equinate group, present in Hypolepis mitis, H. paulistana, H. repens, H. stolonifera and cristate group, present in Hypolepis rugosula. In all species (except in Histiopteris incisa) elements of ornamentation are part of the perispore. At ultrastructural level, the perispore has 1 to 4 layers which differ in structure. Respect to the exospore, all the Dennstaedtiaceae paranaenses species have an exospore two- layered with similar ultrastructural characteristics. The results obtained in this study show that the morphological variability observed in the sporophytes of the family Dennstaedtiaceae species, is equivalent to the variability observed in the sculpture characteristics of the spores. In relation to evolutional history of the family, the results have shown that some palynological characteristic like the kind of spores and the exospore margin would bring data that would support the recent phylogenetic hypothesis. Additionally, these results let us suggest that the palynological characteristics do not have itself any evolutional value that allows us to suggest relationships between groups above generic level. Finally, the detailed descriptions made with LM in the studied species about the exospore and perispore ornamentation, as the images recorded with LM given in this research, will be and useful information for comparison with those spores found in fossil material.