INDUCTION BY ULTRAVIOLET IRRADIATION OF MUTATION IN BLUE-GREEN ALGA NOSTOC LINCKIA (ROTH) BORN ET FLAH

SEVERAL authors1-3 have induced mutations in blue-green algae by ultraviolet irradiation, but the mutation reported here seems particularly significant because it obscures the criteria for delimitation of taxa in the Cyanophyceae4. True branching is a distinctive feature of the algae comprising the order Stigonematales4 and is absent in Nostocales, although algae of the family Scytonemataceae of the latter order show false branching. This is the first report of a mutation induced by ultraviolet irradiation leading to true branching in the typically unbranched genus Nostoc of the order Nostocales. © 1969 Nature Publishing Group.