Identifying seaweeds species of Chlorophyta, Ochrophyta and Rhodophyta using DNA barcodes

Strengthening the DNA barcode database is important for a species level identification, which was lacking for seaweeds. We made an effort to collect and barcode seaweeds occurring along Southeast coast of India. We barcoded 31 seaweeds species belonging to 21 genera, 14 family, 12 order of 3 phyla (viz., Chlorophyta, Ochrophyta and Rhodophyta). We found 10 species in 3 phyla and 2 genera (Anthophycus and Chnoospora) of Ochrophyta were barcoded for the first time. Uncorrected p-distance calculated using K2P, nucleotide diversity and Tajima test statistics reveals highest values among the species of Chlorophyta. Over all K2P distance was 0.36. The present study revealed the potentiality of rbcL gene sequences in identification of all 3 phyla of seaweeds. We also found that the present barcode reference libraries (GenBank and BOLD) were insufficient in seaweeds identification and more efforts were needed for strengthening local seaweed barcode library to benefit rapids developing field such as environmental DNA barcoding. We also show that the constructed barcode library could aid various industrial experts involved in seaweed bio-resource exploration and taxonomy/non-taxonomic researches involved in climate, agriculture and epigenetics research in precise seaweed identification. Since the rise of modern high-throughput sequencing technologies is significantly altering bio-monitoring applications and surveys, reference datasets such as ours will become essential in ecosystem health assessment and monitoring.