Abstract Detail

Phycology

Nowruzi, Bahareh [1].

A proposal for the unification of two strains of cyanobacteria genus Nostoc to the same species.

Studies of cyanobacteria are important to the global scientific community because of their ecological and applied importance. Amongst the different cyanobacterial orders, the Nostocales and Stigonematales orders are especially important as they fix atmospheric nitrogen and thus contribute to the fertility of agricultural soils worldwide. However, in spite of their ecological importance and environmental concerns, their identification and taxonomy is still problematic and confusing, often being based on current morphological and physiological studies, which generates confusing classification systems based on plastic characters that vary with the environmental and cultural conditions.. The present research aimed to investigate through a polyphasic approach, the differences in morphological and genotypic features of two cyanobacteria strains isolated from paddy fields of Iran, belonging to the family Nostocaceae (subsection IV. I). Based on the description of the morphology provided by Desikachary (1959), the two strains were identified as Nostoc ellipsosporum and Nostoc muscorum. Challenges arose when the two Nostoc strains could not be discriminated by 16S rRNA and ITS genes sequencing. The results of sequencing of the cloned bacterial 16S rRNA fragment strongly indicated that the current morphological classification of the two Nostoc species is invalid. Moreover, phylogenetic study of these two Nostoc strains has demonstrated that genetic relationships are in conflict with the morphological classification. Besides, after doing DNA–DNA reassociation experiments, we concluded that the two Nostoc strains investigated might possibly be united into one species.

1 - Department of Biology, Science and Research Branch, Islamic Azad Unive

Keywords:
16S rRNA
ITS
Nostoc
DNA-DNA hybridization.

Presentation Type: Poster
Session: P, Phycological Section Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPC001
Abstract ID:46
Candidate for Awards:None