Avaliação da eficiência de diferentes protocolos de extração de DNA ambiental para levantamentos de biodiversidade a partir de amostras de solo de várzea

Abstract

The use of environmental DNA (eDNA) from Next Generation Sequencing has been projected as an efficient and rapid approach for biodiversity assessment in different environments. However, obtaining quality samples for the optimization of extraction protocols has made its use very costly. Thus, we tested three different treatments (10g, individual and mix), in order to determine the best method that allows a broad identification of biodiversity, using soil samples collected in a floodplain area of the Pixuna do Tapará community, municipality of Santarem - Pa. In this study, the sequencing of the 18S rRNA was performed, a gene widely used for detection and classification of groups of eukaryotic microorganisms. Subsequently, the sequences were submitted to taxonomic identification through the Protist Ribosomal Reference (PR2) v4.14. The results showed that there was a different abundance pattern among the extractions, in which Gastrotricha and Annelida were the most abundant for 10g and the phyla Nematoda, Embryophyceae, Basidiomycota and Arthropoda for individual and Mix extractions. The distribution of ASVs among the different extraction types showed that there are more exclusive representatives than shared ones. For alpha diversity, the pattern between extraction types was similar. There was no statistical difference for Wilcoxon rank-sum tests and Shannon's similarity index. The beta diversity patterns were analyzed using Non-Metric Multidimensional Scaling Analysis (NMDS) using the betadisper function showed similarity between the samples from the individual and mix extractions and a distinction in diversity in the 10g and individual extractions. The significance assessed from similarity analysis (ANOSIM), corroborated the result. The data presented show that depending on the objective and the available resource, the methodology can be employed for both or only one of the protocols.