Microsporogenesis and microgametogenesis of Cardiospermum grandiflorum and Urvillea chacoensis (Sapindaceae, Paullinieae)

• DOI: 10.1071/bt10162
• Publication Date: 2010-10-27T02:38:56Z
• Authors: Stella M. Solís; Beatriz Galati; María S. Ferrucci
• Keywords: Locule; Tapetum

Microsporogenesis and microgametogenesis of two species, Cardiospermum grandiflorum Sw. Urvillea chacoensis Hunz. (Sapindaceae, Paullinieae), were studied using light transmission electron microscopy. Both species are monoecious, with staminate hermaphrodite, although functionally pistillate, flowers. A comparative pollen-development study these floral morphs is reported. For the present study, five stages pollen ontogeny identified. The development anther wall basic type. Its consists epidermis, endothecium, middle layers a uninucleate secretory tapetum. microspore tetrads tetrahedral. mature in flowers presents endothecium well developed fibrillar thickenings, remains tapetal cells, single locule formed theca by dissolution septum before dehiscence two-celled grains when shed. In pistillate flowers, anthers remnants layers, cells without signs degradation, locules uni- or bicellular, some them cytoplasm collapsed. These not dehiscent. It can be concluded that male sterility characterised failure to produce functional grains, an event would associated persistence cells. Ultrastructural analysis clearly shows difference between flower morphs.