Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae)
We analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers hav...
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| Format: | Article |
| Language: | English |
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Consejo Superior de Investigaciones Científicas
2013-12-01
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| Series: | Anales del Jardín Botánico de Madrid |
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| Online Access: | http://rjb.revistas.csic.es/index.php/rjb/article/view/400 |
| _version_ | 1818455801121996800 |
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| author | Ana María González Orlando Fabián Popoff Cristina Salgado Laurenti |
| author_facet | Ana María González Orlando Fabián Popoff Cristina Salgado Laurenti |
| author_sort | Ana María González |
| collection | DOAJ |
| description | We analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers have a tubular 3-lobed perianth, with bilayered and non vascularized tepals. The androecium consists of three stamens with filaments and thecae connated into a synandrium. It has adnate a free central pistillode without megagametophyte. Staminal filaments, fused at their base to the perianth tube and distally free along a short section, have a single vascular bundle. The distal portion of the synandrium is formed by nine pollen sacs: six outer sacs are located laterally to each filament and three longer inner sacs. The anther wall consists of the epidermis, two parietal layers (that collapse at anther maturity), and an uninucleate secretory tapetum. There is no endothecium. During microsporogenesis, the stem cells produce tetrads of microspores by meiosis. The cytokinesis is simultaneous, forming tetrahedrally arranged tetrads. When pollen grains are in the tricellular state, the synandrium emerges from the mass of filariae, and anthers dehiscence occurs apically through longitudinal slits. In conclusion, despite the extreme reduction of flowers, the anatomic characteristics and gametophyte development of staminate flowers of H. cayennensis are perfectly normal and functional. They are thus highly similar to other genera of the holoparasitic subfamily Helosidoideae. Sterile parts of flowers and inflorescence maintain the same distinctive and aberrant features of the plant vegetative parts. |
| first_indexed | 2024-12-14T22:16:33Z |
| format | Article |
| id | doaj.art-305abb97a367450ba1acfdb4a75291c7 |
| institution | Directory Open Access Journal |
| issn | 0211-1322 1988-3196 |
| language | English |
| last_indexed | 2024-12-14T22:16:33Z |
| publishDate | 2013-12-01 |
| publisher | Consejo Superior de Investigaciones Científicas |
| record_format | Article |
| series | Anales del Jardín Botánico de Madrid |
| spelling | doaj.art-305abb97a367450ba1acfdb4a75291c72022-12-21T22:45:36ZengConsejo Superior de Investigaciones CientíficasAnales del Jardín Botánico de Madrid0211-13221988-31962013-12-0170211312110.3989/ajbm.2362379Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae)Ana María González0Orlando Fabián Popoff1Cristina Salgado Laurenti2Instituto de Botánica del Nordeste-IBONE-(UNNE-CONICET), Facultad de Ciencias AgrariasInstituto de Botánica del Nordeste-IBONE-(UNNE-CONICET), Facultad de Ciencias AgrariasInstituto de Botánica del Nordeste-IBONE-(UNNE-CONICET), Facultad de Ciencias AgrariasWe analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers have a tubular 3-lobed perianth, with bilayered and non vascularized tepals. The androecium consists of three stamens with filaments and thecae connated into a synandrium. It has adnate a free central pistillode without megagametophyte. Staminal filaments, fused at their base to the perianth tube and distally free along a short section, have a single vascular bundle. The distal portion of the synandrium is formed by nine pollen sacs: six outer sacs are located laterally to each filament and three longer inner sacs. The anther wall consists of the epidermis, two parietal layers (that collapse at anther maturity), and an uninucleate secretory tapetum. There is no endothecium. During microsporogenesis, the stem cells produce tetrads of microspores by meiosis. The cytokinesis is simultaneous, forming tetrahedrally arranged tetrads. When pollen grains are in the tricellular state, the synandrium emerges from the mass of filariae, and anthers dehiscence occurs apically through longitudinal slits. In conclusion, despite the extreme reduction of flowers, the anatomic characteristics and gametophyte development of staminate flowers of H. cayennensis are perfectly normal and functional. They are thus highly similar to other genera of the holoparasitic subfamily Helosidoideae. Sterile parts of flowers and inflorescence maintain the same distinctive and aberrant features of the plant vegetative parts.http://rjb.revistas.csic.es/index.php/rjb/article/view/400anther developmentbalanophoraceaehelosisholoparasitesmicrogametogenesismicrosporogenesissynandriumunisexual flowers |
| spellingShingle | Ana María González Orlando Fabián Popoff Cristina Salgado Laurenti Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) Anales del Jardín Botánico de Madrid anther development balanophoraceae helosis holoparasites microgametogenesis microsporogenesis synandrium unisexual flowers |
| title | Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) |
| title_full | Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) |
| title_fullStr | Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) |
| title_full_unstemmed | Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) |
| title_short | Structure of staminate flowers, microsporogenesis, and microgametogenesis in Helosis cayennensis var. cayennensis (Balanophoraceae) |
| title_sort | structure of staminate flowers microsporogenesis and microgametogenesis in helosis cayennensis var cayennensis balanophoraceae |
| topic | anther development balanophoraceae helosis holoparasites microgametogenesis microsporogenesis synandrium unisexual flowers |
| url | http://rjb.revistas.csic.es/index.php/rjb/article/view/400 |
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