Studies on Oogenesis of the FernLygodium japonicum
| Autor: | Quan-Xi Wang, Jian-Guo Cao, Yu-Chen Cao, Yan-Dong Guo |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
biology Archegonium Plant Science biology.organism_classification 010603 evolutionary biology 01 natural sciences Oogenesis Plant development medicine.anatomical_structure Human fertilization embryonic structures Botany medicine Fern Pas reaction Nucleus Ecology Evolution Behavior and Systematics Lygodium japonicum 010606 plant biology & botany |
| Zdroj: | American Fern Journal. 107:124-135 |
| ISSN: | 1938-422X 0002-8444 |
| DOI: | 10.1640/0002-8444-107.3.124 |
| Popis: | Oogenesis of Lygodium japonicum (Thunb.) Sw. is studied using TEM and cytochemical techniques. The early development of the archegonia of L. japonicum is similar to those of the core-leptosporangiate ferns. A mature archegonium always contains an egg, a ventral canal cell (VCC) and a binuclear neck canal cell (NCC). With the development of the egg, a separation cavity forms between the egg and the VCC. However, a pore region, with a diameter of about 3.5 μm, constantly connects the egg and the VCC. The canal cells degenerate gradually accompanied by the accumulation of mucilaginous secretions around the canal cells. PAS reaction reveals that these secretions are polysaccharide in nature. Later development of the archegonia of L. japonicum differs greatly from the core-leptosporangiate ferns. The egg nucleus becomes highly irregular and two types of nuclear evaginations are formed during oogenesis. When the egg matures, no egg envelope or fertilization pore are formed. Only a layer of amorphous material is deposited on the outer surface of the egg. This is the first observation of a fern species that has a pore region but does not result in the formation of a fertilization pore. The pore region appears to determine the formation of the fertilization pore. These observations are consistent with the hypothesized phylogenetic position of L. japonicum relative to the core leptosporangiate ferns. |
| Databáze: | OpenAIRE |
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