Morphology and structure of the pollen cone and pollen grain of the Araucaria species from Argentina
Biocell
; 32(1): 49-60, Apr. 2008. ilus
Artículo
en Inglés
| BINACIS
| ID: bin-127184
Biblioteca responsable:
AR40.1
ABSTRACT
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 ect exine 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.(AU)
Texto completo:
Disponible
Colección:
Bases de datos nacionales
/
Argentina
Bases de datos:
BINACIS
Asunto principal:
Polen
/
Tracheophyta
País/Región como asunto:
America del Sur
/
Argentina
Idioma:
Inglés
Revista:
Biocell
Año:
2008
Tipo del documento:
Artículo
Institución/País de afiliación:
CONICET/Argentina
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