Data/hora: 11/06/2024 10:54:50

Provedor de dados: | 47
País: | Argentina
Título: | Morphology and structure of the pollen cone and pollen grain of the Araucaria species from Argentina
Autores: | Fueyo,Georgina M. del; Caccavari,Marta A.; Dome,Elizabeth A.
Data: | 2008-04-01
Ano: | 2008
Palavras-chave: | Araucariaceae; Araucaria; Pollen cones; Pollen ultrastructure.
Resumo: | The pollen cone and the pollen grain of the two Argentinean species of Araucaria are described with LM, SEM and TEM. Primordia of pollen cones are formed in April and May and reach maturity by mid-October in A. angustifolia (Bert.) O. Kuntze and by mid-November in A. araucana. (Mol.) K. Koch. Characters of the mature pollen cones and microsporophylls between both taxa are clearly differentiated. Pollen grains are spheroidal-subspheroidal, inaperturate, and asaccate with granulate exine and a subequatorial annular area that corresponds to the sexine thickness. Sculpturing consists of irregularly dispersed granules that are sometimes fused to each other (A. angustifolia) or forming microrugulae (A. araucana). Microgranules and microspinules are also present. The pollen wall ultrastructure is formed by a granular ectexine and lamellated endexine. Granular elements in A. angustifolia are more loosely disposed, form more interstices, and are gradually smaller towards the endexine than in A. araucana. To asses the probable relationships within the family, we compared the pollen grains of the two Araucaria species with those of other extant genera (Agathis, Wollemia) and also with fossil pollen (Araucariacites, Balmeiopsis, Cyclusphaera, Dilwynites) attributed to Araucariaceae.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452008000100006
Editor: | Sociedad Latinoamericana de Microscopía Electrónica.; Centro Regional de Investigaciones Científicas y Tecnológicas (Mendoza, Argentina)
Formato: | text/html
Fonte: | Biocell  v.32 n.1 2008
Fonte: | info:eu-repo/semantics/openAccess