زینب شریعتمداری - PhD Student, Faculty of Biosciences, Shahid Beheshti University, G.C., Tehran, Iran
حسین ریاحی - Prof., Faculty of Biosciences, Shahid Beheshti University, G.C., Tehran, Iran (E-mail: h-riahi@cc.sbu.ac.ir)
شادمان شکروی - Assistant Prof. Faculty of Basic Science, Islamic Azad University, Gorgan Branch, Gorgan, Iran

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, ۱۹ 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. 

Algal extract, Biofertilizer, CYANOPHYTA, Iran, morphospecies