GLYPHOSATE RESISTANCE IN THE VINEYARDS IN OLTREPO PAVESE (ITALY): THE CASE OF ECHINOCHLOA CRUS-GALLI (L.) P. BEAUV

Echinochloa crus-galli (L.) P. Beauv. (barnyard-grass) is a widespread weed, particularly noxious to agriculture due to its ability to resist toward many herbicides, including broad spectrum ones, such as glyphosate. In the recent years E. crus-galli glyphosate resistant populations have been identified in vineyards of northern Italy. In the project VINO (VIneyard management for viNeprOduction), part of the NODES ecosystem funded by the MUR – M4C2 1.5 of PNRR funded by the European Union - NextGenerationEU (Grant agreement no. ECS00000036), the analysis of glyphosate resistance in weed populations in vineyards of the Oltrepo Pavese wine-growing area (Lombardy) has been performed, assessing the target site resistances (TSRs), the non-target site resistances (NTSRs) and those regulated by epigenetic mechanisms (i.e. miRNAs). E. crus-galli specimens survived glyphosate application were collected and DNA was extracted. Amplification of the EPSPS (5-enolpyruvylshikimate-3- phosphate synthase) gene was performed. Restriction fragment length polymorphism (RFLP) analysis was used to detect the presence of a mutation at Pro-106 codon of EPSPS gene known to be involved in glyphosate TSR in E. crus-galli. Electrophoretic profiles analysis revealed that the frequency of TSRs was low. Glyphosate enzymatic detoxification (NTSRs) is the most frequent mechanism leading to resistance occurrence. The analysis of genetic-environmental interactions and of weeds adaptation toward stressors (i.e. herbicides) is crucial to better understand the nature of resistance, with the aim of optimizing precision weed management (PWM), planning more targeted and sustainable strategies to manage herbicide resistance, reducing inputs, protecting the agro-ecosystem, hence improving the agri-food supply chain sustainability.