This document provides information about the cyanobacteria Oscillatoria. It discusses its systematic position as a genus in the order Oscillatoriales, describes its occurrence in moist places with decaying organic matter, and details its plant body structure as unbranched trichomes of cylindrical cells contained in a thin sheath. Reproduction is solely vegetative, occurring through the formation of harmogonia fragments or accidental trichome breakage. Oscillatoria has economic importance for soil reclamation, pollution indication, oxygen production, symbiotic associations, protein content, and nitrogen fixation.

2. OSCILLATORIA
Presented to Madam Rabia Saba
Presented by Iqra Naz
BS-BOT-F17-R12.

3. Contents
• Systematic position.
• Occurrence.
• Plant body.
• Cell structure.
• Reproduction.
• Economic importance.
• References.

4. Systematic Position
• Class : Cyanophyceae
• Order : Oscillatoriales
• Family : Oscillatoriaceae
• Genus : Oscillatoria

5. Occurrence
• Found in moist places.
• Found in places rich in decaying organic
matter.
• It forms thin blue green coating on the surface
or edges of flowing water.
Common species
• Oscillatoria formosa
• O.princeps

6. Plant body –thallus
• Plant body consist of single row of cells
forming unbranched trichomes with a very
thin gelatinous sheath.
• Cells are broader than longer but cylindericalt.
• All cells are similar in trichome with the
exception of apical cells.(convex at the top)
• trichomes are usually naked and have a thin
poorly developed sheath.

7. Cell Structure
• The cell is prokaryotic in nature.
• A cell in the trichome is differentiated into two
parts
1. Cell wall:
• well developed.
2.Protoplasm:
• Have peripheral and central cytoplasm.

8. • Pigments.
Cholophll a,carotenes,xanthophylls and
phycobillins.
• Reserve food materials.
starch,lipids and cyanophycian(protein).

9. Reproduction
• SEXUAL REPRODUCTION.
No sexual reproduction present in
oscillatoria.
• VEGETATIVE REPRODUCTION.
Reproduction occur through vegetative parts.
Two methods
1. By harmogonia.
2. By fragmentation.

10. By Harmogonia.
• Harmogonia are the short segment of trichome
which consist of few cells.
Formation.
• Form by the formation of separation disc.
• Which are also called as necridia.
• The disc are formed by the death of one or more
cells of filament.
• These disc are mucilaginous,pad-like and
biconcave.

11. • The disc then absorb water and break into
small fragments.
• Form new oscillatoria under favourable
conditions.

12. By Fragmentation
• Accidental breakage of trichome cause
formation of small fragments.
• Which can develop into new oscillatoria.

13. Economic importance
• Help in reclamation of alkaline soil.
• Use as pollution indicator.
• Produce the greater amount of oxygen.
• Form symbiotic association with
protozoa,plant and fungi.
• Source of protein.(60% protein obtain from it)
• Help in nitrogen fixation.

14. References
• Textbook of botany
paper A for B.Sc.

15. The End