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- Title
ULTRASTRUCTURE OF TETRASPOROGENESIS IN PALMARIA PALMATA (RHODOPHYTA).
- Authors
Pueschel, Curt M.
- Abstract
The tetrasporangial initial in Palmaria palamata (L.) O.Kuntze (formerly Rhodymenia palmate (L.) Greville) arises from a cortex cell which enlarges and deposits a protein-rich wall layer. This cell undergoes mitosis to form a tetrasporocyte and a stalk cell. Synaptonemal complexes are formed in the sporocycle nucleus while in the cytoplasm floridean starch is deposited in association with ER or with particles presumed to be ribosomes. Microbody like structures become numerous between the nuclear envelope and perinuclear ER, and clusters of non-membrane, spherical structures also are associated with the nucleus. Chromatin condensation is reversed following pachytene and a prolonged diffuse stage ensues, when dictyosomes and ER produce vehicles which deposit mucilage rich in sulfated and acidic polysaccharides around the tetrasporocyte. A conspicuous lenticular thickening of the mucilage sheath develops at the apical end of the sporangium. Dictyosomes are frequently associated with mitochondria which may be associated with chloroplasts. Following nuclear divisions the tetrasporocyte is cleaved into four spores by sequentially initiated, but simultaneously completed periclinal and anticlinal furrows. When mucilage deposition ceased, the dictyosomes begin to produce vehicles awiath glycoprotein-rich contents. These vehicles are abundant in released tetraspores, and they probably contain adhesive material aiding in the attachment of the liberated spores.
- Subjects
PALMARIA; PALMARIACEAE; RED algae; RHODYMENIA; RHODYMENIACEAE; MITOSIS
- Publication
Journal of Phycology, 1979, Vol 15, Issue 4, p409
- ISSN
0022-3646
- Publication type
Article
- DOI
10.1111/j.1529-8817.1979.tb00713.x