Study On The Protists Diversity Of The Longfeng Wetland And Hulan Estuary Wetland In Heilongjiang Province

Wetland is one of the most important ecosystems on the earth,and it has a powerful ecological purification effect,so it has the reputation of "the kidney of the earth".Protists are single-celled microeukaryotes including eukaryotic algae and protozoa.They are main components of the material and energy flows in wetland ecosystems,and are sensitive indicators for wetland ecological functions and health.This study uses traditional morphological methods and high-throughput sequencing technology to study the protists biodiversity of the Longfeng Wetland and Hulan estuary Wetland in the typical urban wetlands of Heilongjiang Province,and explore the native biodiversity,community structure and it's relationship with environmental factors.The main results were as follows.(1)The diversity of protozoa in Ciliophora and Amoebozoa in Longfeng Wetland and Hulan estuary Wetland was studied by morphological methods.Protozoa of 8classes and 7 classes in 2 phyla were identified in the two wetlands,and the dominant groups were Oligohymenophorea and Spirotrichea.(2)Amplicon sequencing obtained 4012 operational taxonomic units(OTUs)in the investigation of the protists biodiversity of Longfeng Wetland,belonging to 14 phyla,67 classes,103 orders,120 families,and 231 genera.Metagenomic sequencing resulted in 233 protists OTUs belonging to 12 phyla,49 classes,70 orders,80 families,and 89 genera.Comparing the abundance and richness of the protists communities,the two methods concluded that the dominant groups of protists in the Longfeng wetland were Stramenopiles and Alveolata.The results of Linear Discriminant Analysis Effect Size showed that the species with significant differences include Cyclotella and Trebouxiophyceae.(3)Amplicon sequencing obtained 4229 OTUs in the investigation of the protists biodiversity of Hulan estuary Wetland,belonging to 14 phyla,73 classes,109 orders,127 families,and 241 genera.Metagenomic sequencing resulted in 232 protists OTUs belonging to 12 phyla,49 classes,70 orders,80 families,and 89 genera.Similarly,the dominant groups of protists in Hulan estuary Wetland were Stramenopiles and Alveolata.The results of Linear Discriminant Analysis Effect Size showed that the significantly different species screened based on amplicon data and metagenomic data were Stokesia and Stephanodiscus,respectively.(4)In the investigation of the protists biodiversity of the Longfeng Wetland and the Hulan estuary Wetland,based on the two sequencing methods,the dominant taxa of the two wetlands were consistent,and the relative abundance of the other taxa at the phylum level are different.The relative abundance of Chlorophyta in Longfeng Wetland was higher than that in Hulan estuary Wetland,while the proportion of Cercozoa was the opposite,which may be mainly related to environmental factors.The results of redundancy analysis showed that the protists community in Longfeng Wetland was positively correlated with salinity,while the protists community in Hulan estuary Wetland was positively correlated with temperature.(5)High-throughput sequencing technology can obtain a large number of species that can't be cultivated or identified by traditional morphological methods,and has a higher reduction ability for microbiological communities.It is used in the investigation of biodiversity in aquatic ecosystems and its relationship with environmental factors.There is huge application potential.The biological species detected by amplicon sequencing is higher than that of metagenomic sequencing,but the data obtained by metagenomic sequencing is more primitive and accurate.