Algae is the earliest evolutionary biological group on the earth, are thought to have appeared at least 2.6 billion years ago. As the most complex biological group, algae have shown the high diversity during the long evolutionary history. Algae are widely distributed in 4 kingdoms of the Eukaryota, including the Plantae, Protozoa, Acritarcha, Chromista and Fungi. Up to now, there are 46,177 species of eukaryotic algae have been recognized and classified (AlgaeBase, 2020), but in fact, more species need the further confirmation.

The mitochondria and chloroplast are unique organelles in the biological systems which have their own distinct DNA. The conformation of DNA can be circular or linear and the mode of replication is different from that of the nuclear genome. The structural and genomic variations in these organelles would reveal the evolution characteristics of different algae further.

However, an integrative organelle genomic database for multiple algae which enables users to jointly examine and use relevant data have not been available. To provide an organelle genomics platform for the algae, we developed a user friendly database named the OGDA. Currently, OGDA contains genomic data from public databases, and organelle genome data determined by our own laboratory. A variety of applications were integrated in this website to analyze the structural characteristics, collinearity and phylogeny of organelle genomes from algae.