The Pallikaranai Marshland has spread over 1,247.5 ha of land and serves as an aquatic buffer of the flood-prone Chennai and Chengalpattu districts. Chlorella is a common green alga and widely distributed in Indian freshwater habitats. Identifying Chlorella species based on morphological characteristics can be challenging and there is a need for a reliable and accurate method to assess genetic variations. DNA barcoding is an effective method to identify diverse algal species across various taxa and habitats. This study aims to apply molecular approaches for the identification of algae isolated from using rbcL gene. Molecular identification of the isolates 23SPPCA01, 23SPPCA02, 23SPPCA03, 23SPPCA05 and 23SPPCA06 from the study area has been done. The rbcL gene, which encodes the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), is widely recognized for its role in DNA barcoding of plants and has also been developed for molecular identification of microalgae. The results revealed that isolates 23SPPCA01 and 23SPPCA05 were found to be Chlorella variabilis and Chlorella vulgaris respectively with a genetic similarity of 99% toward identified species in the NCBI database using BLAST program. Similarly, the isolates 23SPPCA02, 23SPPCA03, and 23SPPCA06 were reported as Chlorella sorokiniana. Further, the DNA sequences were submitted to NCBI database and received accession numbers viz., PP316335, PP316336, PP316334, PP196469 and PP110481. The phylogenetic analysis indicated that the isolates of Chlorella belong to both clades and clearly distinguished. This research provides the valuable perceptions into the molecular identification and phylogeny of Chlorella sp. from an ecologically significant spot and allow us to enhance conservation efforts.

Molecular identification, Chlorella, rbcL gene and Pallikaranai

The current study reveals that rbcL could be used as one of the molecular markers for species-level identification in Chlorella species through DNA barcoding. Although this molecular marker shows promising results, it is important to consider morphological examination as a complementary approach. This research provides the valuable perceptions into the molecular identification and phylogeny of Chlorella sp. From Pallikaranai Marshland. The paper emphasis the documentation of authentic diversity data in ecologically significant locations may helpful us to enhance conservation efforts.

S. Palanivel, S. Ibrahim, D. Tharun Kumar, S. Shravani, M. Salma Sulthana and A. Srinivasa Rao (2024). Molecular Identification and Phylogenetic Relationship of Chlorella species from Pallikaranai Marshland using rbcL Gene. Biological Forum – An International Journal, 16(6): 203-209.