Study of soil blue-green algae and their effect on seed germination and plant growth of vegetable crops

Nitrogen fixation blue-green algae make a major contribution to the fertility of soil. It has been suggested that blue-green algae (BGA) assist higher plant growth by supplying growth substances. There are numerous works about roles of blue-green algae in paddy soils and rice growth but little on other plants. In this research, 19 morphospecies belonging to three families of heterocystous and non-heterocystous blue-green algae from several paddy fields in the north of Iran were identified out of which seven species are new to Iran.