Ovule ontogeny and megasporogenesis in Jacaranda mimosifolia D.Don. (Bignoniaceae)
The ontogeny of the ovule and megasporogenesis in Jacaranda mimosifolia D. Don. was investigated. There is no previous account about ovular initiation in the family Bignoniaceae. The mature ovule is anatropous, unitegmic and tenuinucellate. The ovular primordium is bizonate and the integument is of...
| Autores principales: | , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00319449_v49_n1_p67_Galati |
| Aporte de: |
| Sumario: | The ontogeny of the ovule and megasporogenesis in Jacaranda mimosifolia D. Don. was investigated. There is no previous account about ovular initiation in the family Bignoniaceae. The mature ovule is anatropous, unitegmic and tenuinucellate. The ovular primordium is bizonate and the integument is of dermal origin. Cytoplasm is highly concentrated at the chalazal pole of the megaspore mother cell which undergoes meiosis; this polarity may be related with the selection of the functional megaspore. Linear or T-shaped tetrads of megaspores are formed of which the lowermost is functional and produces an Polygonum type of embryo sac. During the course of megasporogenesis, callose appears only along the transverse walls in dyads and tetrads. |
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