Cyanobacterial diversity occurring in some local rice fields of Guntur District, Andra Pradesh has been studied. A total of 38 cyanobecteria were observed among which 18 taxa were determined and characterized as non- heterocystous, unicellular, colonial and filamentous forms and 20 were identified as heterocystous. For each taxon, a description based on morphological and reproductive characters were made and recorded along with information on the geographical distribution in the study area. This study is aimed to describe the Morphological features and distribution of cyanobacteria in various rice fields of Guntur district areas. The present study concludes that the distribution of heterocystous and non-heterocystous forms of algae enhances soil fertility so as to increase the rice yield. The physico-chemical parameters such as temperature, pH, salinity, dissolved oxygen and total dissolved solids were analysed during June 2010 to November 2010. The temperature, pH and salinity were increased during summer season and dissolved oxygen and total dissolved solids were decreased in summer season. The chemical parameter, Biological oxygen Demand(BOD),Chemical oxygen Demand, Carbonate and Chloride were also estimated.
Paddy fields,Cyanobecteria, Physico-chemical Parameters and Heterocystous.