A Biosystematics Study of Microcystis (Cyanobacteria), A Bloom-Forming Cyanobacterium from Aras Reservoir (North-West Iran)
نویسندگان
1 Assistant Prof., National Artemia research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Uramia, Iran
2 Associate Prof., National Artemia research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Uramia, Iran
3 Faculty of Biological Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
4 Assistant Prof., National Artemia research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Uramia, Iran
5 Associate Prof., National Artemia research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Uramia, Iran
6 Assistant Prof., National Artemia research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Uramia, Iran
doi
چکیده
Today, harmful cyanobacerial bloom is consideredas a main problem in freshwater ecosystemsall over the world. The Microcystis is an importantgenus in cyanobacteria composed of about 23species. This genusforms various shaped coloniesincluding spherical or oblong cells which wholecolony is surrounded by a mucilage sheath. Manypopulations and species of the genus produce severblooms and often toxins in eutrophic freshwaters.The genus Microcystis has been defined based onmorphological, morphometrical and genetical criteria,however, its classification under the genuslevel is still indistinct and presence of traditionalmorphological species within the genus is doubtful.Therefore, determining of the natural diversityunder the genus level in Microcystis has a crucialimportance. The purpose of this study was to determinethe species of Microcystis in Aras reservoir.The samples were collected from 6 sampling siteson 18 August 2013. Morphological and morphometricalstudies of Microcystis was carried out byNikon 50i microscope equipped with Nikon DSFicamera and Nikon monitor with length measurmentsoftware. Principal Component Analysis(PCA) and two-way Unweighted Pair GroupMethod with Arithmetic Mean (UPGMA) byPAleontological STatistics (PAST) version 3.04were performed to determine biosystematics variationsbetween Microcystis populations. The resultsindicated that Microcystis from Aras reservoirwas composed of two distinct groups based on theshape and size of cells, colony form, presence andabsence of gelatinous sheath around the colonies,etc).These two groups may be considered as twomorphospecies of M. botrys which are separateddue to different ecological factors.
