Zeinab Shariatmadari - Faculty of Biosciences, Shahid Beheshti University, G.C., Tehran, Iran
Hossein Riahi - Faculty of Biosciences, Shahid Beheshti University, G.C., Tehran, Iran
Ali Sonboli - Biology Department, Medicinal plants and Drugs Research Institute, Shahid Beheshti University, G.C. Tehran, Iran.

In present study, Anabaena isolates were collected from paddy field soils of seven main rice cultivation provinces situated in north, centre, south, west and east of Iran during ۲ years from April ۲۰۰۸ to May ۲۰۱۰. Identification of taxa was carried out based on morphometric and molecular methods. Twenty one morphological characters and numerical taxonomic methods were used for classifying the several species of this genus. Numerical taxonomic studies were performed on ۳۴ populations of ۱۳ Anabaena morphospecies. A cluster analysis and principal component analysis performed using SPSS software and rate of resemblance among the species recognized. In the other section of this study phylogenetic relationships were determined by constructing ۱۶S rRNA gene tree using the neighbor-joining algorithm. The results showed that populations of each species were placed close to each other and separate from the other species base on morphological characters. According to factor analysis, colonies form, filament structure, apoheterocytic or paraheterocytic form of filaments, position, shape and number of akinetes in filament, presence or absence of gelatinous sheath were the most variable characters which have been used for identification. Phylogenetic analysis based on ۱۶S rRNA gene sequences also indicated that this gene site cannot separate genera such as Anabaena, Trichormus and Wollea which are morphologicaly close to each other.

Anabaena, cluster analysis, factor analysis, morphospecies, numerical taxonomy