A study of the blue-green algae from paddy field soils of India

Summary

The blue-green algal flora of rice-field soils of India was explored. The places from where collections were made are: Katni and Jabalpur (Madhya Pradesh state); Karjat and Nagpur (Maharashtra state); Maddur and Naganahalli (Mysore state); Mahabalipuram, Aduturai and Paramakkudi (Madras state). A total flora of 132 forms is reported. There are twenty one new forms including one genus, three species, three varieties and 14 form varients. The algae have been observed both in nature and culture and an average of 23 forms was found in each soil. The algae obtained from nature comprise 37.8% of the total recorded. Those obtained from culture show a higher percentage (48.4), but the percentage of algaetthat are common to both nature and culture is 13.6. The relative abundance of blue-green algae under cultural conditions have also been observed by other workers. The present study also confirms the observation of other workers that soils contain a large number of viable algal species apart from those actually visible and that some algae reported from nature, may fail to appear under cultural conditions. The heterocystous blue-green algae are seen less than non-heterocystous in nature whereas in cultures the condition is reverse.