Development and ultrastructure of the megagametophyte in Passiflora caerulea L. (Passifloraceae)

AMELA GARCÍA, M. T., GALATI, B. G. & ANTON, A. M. R.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

Cardiff University

Lugar: Cardiff; Año: 2003 vol. 142 p. 73 - 81

0024-4074

Megasporogenesis and megagametogenesis of Passiflora caerulea L. was studied with light and transmission electron microscopy. The archesporial tissue is generally formed by one cell. The megaspores mother cell gives rise to a linear tetrad of megaspores. The chalazal megaspore is the functional one, which originates a Polygonum type female gametophyte. The antipodals are ephemeral. Abundant starch is found in the nucellar cells, specially the ones adyacent to the megagametophyte. The two synergids show ultrastructural differences, involving the filiform apparatus, the nucleous and the endoplasmic reticulum; these differences suggest a functional differentiation, probably related to the reception of the pollen tube. This is the first report for Angiosperms of substantial morphological differences between both synergids.