DNA ambientale per la caratterizzazione della biodiversità nel suolo di risaia in agroforestry

[Machine translation] Environmental DNA for the characterization of biodiversity in rice field soil in agroforestry Italian Zoological Union 83rd UZI Congress The study of environmental DNA (eDNA) is currently one of the most innovative techniques used for the rapid characterization of organisms present in an environment (TABERLET et al., 2012). eDNA applied to agroecosystems offers the possibility of monitoring biodiversity in an ecosystem under strong anthropogenic pressure. In addition, soil is among the least studied terrestrial environments, despite hosting a considerable percentage of the entire world's biodiversity and providing numerous ecosystem services (KESTEL et al., 2022). In this context, European indications aim at agriculture that favors environmental heterogeneity, such as the practice of agroforestry, which combines the cultivation of productive herbaceous plants interspersed with tree plants (MOSQUERA-LOSA et al., 2023). The study presented aims to characterize the communities of Protists and Metazoi through metabarcoding on eDNA from paddy soil cultivated in agroforestry and without input of pesticides. eDNA was extracted from soil samples collected at different rice production phases. The sequencing focused on two genes (18S rRNA and COI) and was carried out using Illumina technology. The sequences obtained were analyzed with various dedicated software. The preliminary results show for Protists a community dominated by consumers such as Cercozoa, Ciliophora and Amoebozoa, where α-diversity tends to decrease in the different phases, to recover to its initial values at the maturation phase. For the Metazoi communities, on the other hand, the trend of α-diversity is stable throughout the cultivation period, with the Annelida and Arthropoda taxa most represented. The beta-diversity analyses on Protists and Metazoans show different situations, with a specialization in the different phases for the first group and stable communities for the second. A possible explanation lies in the direct impact on Protists of submersion during the cultivation phases, which allows the survival of fewer species with adaptability to the new conditions established, a behavior also known in the Bacteria kingdom (NASUELLI et al., in prep). Among the Metazoans we find organisms more influenced by seasonality (e.g. Lissorhoptrus oryzophilus) and adapted to the environmental conditions imposed by the rice field (e.g. Isotomurus palustris, Rhopalosiphum rufiabdominale). Further research is necessary, for example, expanding to farms with different cultivation protocols (e.g. conventional agriculture).