Molecular typing and distribution of filamentous heterocystous cyanobacteria isolated from two distinctly located regions in North-Eastern India

Abstract

The diversity of cyanobacteria in the North-Eastern region of India has not been studied except for a few sporadic and inconclusive reports. Loktak Lake is a huge reservoir for various kinds of organisms, including cyanobacteria. The present study describes the isolation and molecular diversity of 72 filamentous, heterocystous cyanobacterial strains isolated from samples collected from Loktak Lake, its adjoining rice fields and rice fields in Indian Council of Agricultural Research (ICAR) complex, Shillong, Meghalaya, India. The isolated strains belonged to the genera Anabaena, Nostoc, Calothrix, Cylindrospermum and Mastigocladus. The molecular analysis of isolates revealed the occurrence of certain strains being present in the sample collected from the rice fields falling in the catchment area of Loktak Lake, Manipur and rice fields in ICAR complex, Shillong, Meghalaya both. A polyphasic approach based on morphological features and PCR based molecular polymorphism revealed enormous level of molecular diversity. Out of three primers targeted regions used for determining genetic polymorphism, STRR1A produced best fingerprint profile of cyanobacterial strains. The morphological diversity of isolates was assured by light microscope whereas PCR based multiple fingerprint profile was used for molecular characterization. Molecular typing using short tandemly repeated repetitive STRR1A sequences as primer provided strain specific fingerprint profiles of the isolates.