Taxonomic status of Anabaena azollae

Abstract

Despite the long-standing and widespread use of the symbiotic association between the aquatic fern Azolla and its cyanobacterial symbiont Anabaena azollae to augment nitrogen supplies in rice paddy soils, very little is known about taxonomic aspects of the symbiosis. The two partners normally remain associated throughout vegetative and reproductive development, limiting the opportunities for interchanges. We have used monoclonal antibodies and DNA/DNA hybridization techniques to show that the cyanobacterial partner is not uniform throughout the genus Azolla, and that substantial diversification has occurred. With these procedures it will be possible to characterize genotypes of the cyanobacterium and to monitor experiments aimed at synthesizing new combinations of Azolla species and Anabaena azollae strains. Show more