Oscillatoria

uos sub campus bhakkar

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

2. Contents Systematic position. O ccurrence. Plant body. Cell structure. Reproduction. Economic importance. References.

3. Systematic Position Class : C yanophyceae Order : O scillatoriales Family : O scillatoriaceae Genus : O scillatoria

4. O ccurrence 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. C ommon species Oscillatoria formosa O.princeps

5. 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.

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

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

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

9. By H armogonia . 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.

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

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

12. 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.

13. References Textbook of botany paper A for B.Sc.

14. The End