Applicability of diatom metabarcoding in the ecological status assessment of Hungarian lotic and soda pan habitats

Diatoms are widely applied in the ecological status assessment of aquatic ecosystems using indices calculated from pollution sensitivity and indicator values species. Traditional, morphology-based identification species requires in-depth taxonomic knowledge expertise. Identifying taxa according to their barcode sequences obtained with high-throughput sequencing (metabarcoding) would be a promising alternative. In this pilot study, we tested applicability metabarcoding benthic diatom assemblages for Hungarian water bodies, comparing its performance that The region rbcL gene was investigated samples running waters various trophic states unique lentic habitats, namely soda pans. For waters, Specific Pollution Sensitivity Index (IPS) pans H index Indice Biologique Diatomées (IBD) were morphology- sequence-based abundances. quality ratio determined waters. Overall, more infrageneric found microscopy than lotic samples. correspondence between taxon lists detected by two methods relatively low but increased considerably case morphologically dominant taxa. Community composition based on DNA sequence analysis showed significant correlation same main environmental drivers. Morphology-based strongly correlated indices. Both aspects indicated class half other cases, shift good moderate frequent, phenomenon could prove problematic because Water Framework Directive prescribes intervention or worse status. Considering discrepancies results metabarcoding, both parallel proposed until reference database has been suitably updated.