TAMIRES O. MELO, UNIVERSIDADE FEDERAL DO PARANÁJOACHIM KOPKA, MAX‐PLANCK‐INSTITUT FÜR MOLEKULARE PFLANZENPHYSIOLOGIEIVAR WENDLING, CNPFALEXANDER ERBAN, MAX‐PLANCK‐INSTITUT FÜR MOLEKULARE PFLANZENPHYSIOLOGIEFRANCISCO A. MARQUES, UNIVERSIDADE FEDERAL DO PARANÁFABRICIO AUGUSTO HANSEL, CNPF.2026-07-07http://hdl.handle.net/123456789/438181This study presents an integrated multivariate and univariate analysis of circadian metabolomic signatures in Ilex paraguar-iensis (yerba mate) clones cultivated under semi-hydroponic conditions. Using repeated measures ANOVA–SimultaneousComponent Analysis (RM-ASCA+) and hierarchical clustering on principal components (HCPC), we explored clone-specificand photoperiod- dependent metabolic responses across light and dark phases, complemented by high-resolution timepointsampling (HRS) and targeted screening. Clone EC21 exhibited elevated levels of sugars, amino acids, and organic acids, sug-gesting a metabolic strategy adapted to saline stress and nocturnal energy demands. Photoperiod effects revealed circadianregulation of central carbon metabolites (e.g., glucose, fructose, maltose) and phenylpropanoid intermediates linked to bio-active compounds such as caffeoyl- quinic acids. Interaction effects highlighted metabolic plasticity, particularly in nitrogenassimilation, with compounds like 2- oxo-glutaric acid, glutamine, and ornithine showing clone- specific temporal patterns.Caffeine, a heritable and physiologically relevant metabolite, displayed distinct circadian profiles. EC24 accumulated caf-feine during the day, while EC21 peaked at night. This dynamic distribution, supported by allantoin patterns in caffeinecatabolism, suggests divergent nitrogen turnover strategies between clones. These findings underscore the importance ofgenotype selection and temporal regulation in optimizing yerba mate performance under semi-hydroponic systems. Thecombined use of RM-ASCA+ and univariate analysis proved to be a powerful approach for profiling metabolomic rhythms,offering valuable insights for breeding programs targeting bioactive compound enhancement, stress resilience, and meta-bolic efficiency.openAccessErva mateIlex ParaguariensisCultivo HidropônicoCloneMelhoramento Genético VegetalYerba mateHydroponicsClonesBreeding and Genetic ImprovementArtigo de periódico