Life cycle of Oedogonium for B.Sc. students

Vegetative Structure of Oedogonium 

Oedogonium is a Filamentous, Unbranched green algae. It is an Aquatic common green alga. It is free-living and sometimes epiphytic on sub merged plants.

• The filament of Oedogonium comprises of main three parts
• Holdfast
• Apex
• Row of Cells
• A basal cell through which the filament attached to any surface is called as holdfast, It is irregularly lobed.
• Apical cells-Cells are cylindrical, sometimes slightly broader at the anterior end, charac terized by one or more ringlike caps immediately below the cross wall
• Cells often having distally one or several ringlike growths or ridges (cap cells)
• Each unbranched filament consists of row of elongated cells.
• Cells are of following types- Antheridia; cells, Oogonial cells, Suffultory cells and cap cells.

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Vegetative structure

Structure of a cell: Cell wall consist of cellulose internally, Pectose in middle and chitin externally.

• Parietal, netlike chloroplast and several pyrenoids.
• Each cell has a single nucleus and network like reticulate chloroplast.
• Antheridial cells are involved in production of Antherozoids(2)
• Suffultory cell are supporting cells just below oogonial cells.

SEXUAL REPRODUCTION

• Sexual Reproduction is of Advanced Oogamous types.
• Many species are MONOCEIOUS (Homothallic)and some are DIOCEOUS (Heterothallic).
• In Homothallic species Antheridia and Oogonia are on single filament.
• In Hetrothallic species Antheridia and Oogonia are on different filaments.

The Monoecious or Homothallic species of Oedogonium produces Antheridia and Oogonium on same plant and ther are termed as Macrandrous form.

The Dioecious or Hetrothallic species of Oedogonium produces Antheridia and Oogonium on different filament. In Nanandrous form oogonia are formed on Normal sized filament and Antheridia are formed on dwarf male filament.

STEPS IN LIFE CYCLE

Diagramatic representation of life cycle