IBONE   05434
INSTITUTO DE BOTANICA DEL NORDESTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Development of pollen and anatomy of the mature anther in Argentinian species of the three subfamilies of Rubiaceae
Autor/es:
GONZALEZ, A.M.; ROMERO, M.F.; JUDKEVICH, M.D.; SALAS, R.M.; NUÑEZ FLORENTIN, M.
Lugar:
Copenhagen
Reunión:
Conferencia; VII International Rubiaceae and Gentianales Conference; 2017
Institución organizadora:
Natural History Museum of Denmark - Botanica
Resumen:
Rubiaceae is a cosmopolitan family that includes about 1300 species distributed in three subfamilies: Cinchonoideae, Ixoroideae, and Rubioideae. The microsporogenesis, microgametogenesis, and the structure of the mature anther were described in Argentinian species of the three subfamilies for comparative purposes. The study includes two perfect species: Cephalanthus glabratus (Cinchonoideae) and Oldenlandia salzmannii (Rubioideae) and a structurally perfect but functionally imperfect species: Randia ferox (Ixoroideae). Wefollowed conventional techniques of optic microscopy. In the two perfect species and in the functionally staminate flowers of Randia the development of the pollen follows a normal pattern: the meiosis of the microspore mother cells originates tetrahedral and decussate tetrads. In C. glabratus and O. salzmannii, tetrads are separated in free microspores and the pollen is released in monads, while in Randia the pollen in permanent tetrads. The perfect flowers of Cephalanthus and Oldenlandia, and the staminate flowers of Randia present theanther wall only with remains of exothecium and endothecium with fibrous thickenings and show a normal dehiscence; the pollen grains are dispersed in bicellular state. In the functionally pistillate flowers of Randia, the microspore mother cells collapse and there is a progressive deterioration of the parietal strata and tapetum; the mature anther is only constituted by exothecium and endothecium without thickenings, and there is not pollen grain development. This work is a contribution to studies of reproductive anatomy, which are currently performed in Argentinian Rubiaceae species.