Effects of long-term drought stress on soil microbial communities from a Syrah cultivar vineyard
Changes in the rainfall and temperature patterns affect the increase of drought periods becoming one of the major constraints to assure agricultural and crop resilience in the Mediterranean regions. Beside the adaptation of agricultural practices, also the microbial compartment associated to plants should be considered in the crop management. It is known that the microbial community change according to several factors such as soil composition, agricultural management system, plant variety and rootstock. Considering the increasing pressure of the biotic and abiotic stresses, it is utmost necessary to also evaluate the effects of drought on the microbiome associated to grapevine in a sensitive Mediterranean region (Alentejo – Portugal).
In this study we characterize the diversity and the structure of the soil microbial community of the drought tolerant Syrah cultivar under long-term irrigation experiment (five years) with three levels (100% ETc – FI; 50% ETc – DI; rain-fed – NI). Metabarcoding of bacteria (16S rRNA subregion) and fungi (ITS region) was applied on the same soil samples. Also soil chemical analysis are being integrated with genomic data.
Although the richness and evenness indexes for alpha diversity did not show strong differences among the irrigation strategies for neither of the targeted microorganisms, beta diversity revealed statistically supported community differentiation. Across all samples the top three bacterial phyla were Pseudomonadota, Actinobacteriota, and Bacteroidota with a total relative abundance of 60%. Regarding the most represented bacterial species across samples, Gaiella occulta, an uncultured actinobacteria first described in deep mineral waters in Portugal, is shown with prevalence in DI samples with more than 10% of total ASVs.
Next, we will predict communities functionalities, bacterial networks, according to soil chemistry data and compare them with the soils’ samples obtained in July 2023.
Issue: ICGWS 2023
1Faculdade de Ciências, University of Lisbon, Portugal
2BioISI, Faculdade de Ciências, University of Lisbon, Portugal
3LEAF – Linking Landscape, Environment, Agriculture and Food Research Centre, Associate Laboratory TERRA, ISA-ULisboa, Lisboa, Portugal
4COLAB, Torres Vedras, Portugal
5INIAV, Polo de Dois Portos, Portugal