Do Specialized Metabolites Drive the Success of Willow Hybrids?

Natural hybrids of Salix alba × fragilis are widespread along the Elbe River in Czechia, yet the ecological and chemical factors behind their success remain poorly understood. In our newly published study, we explore whether hybridization influences the diversity of specialized metabolites—and how this, in turn, affects herbivory and environmental adaptability.

By analysing leaf chemistry, we found that the hybrids typically exhibit intermediate levels of metabolite concentration and richness compared to their parental species. However, they stand out with higher structural α-diversity, suggesting greater within-individual chemical complexity. Interestingly, most hybrid-specific compounds were structurally close to those of the parent species, indicating subtle chemical modifications rather than radical shifts.
Although overall herbivory levels did not differ significantly among hybrids and parental species, herbivore responses varied depending on metabolite richness and structural diversity. Notably, soil nitrogen levels were linked to structural variation in metabolomes, with hybrids showing greater chemical variation along nitrogen gradients. These findings suggest that while hybridization alters chemical structure only moderately, the resulting diversity may provide adaptive flexibility to changing soil conditions, potentially contributing to the ecological success of these hybrids.



Renoult S.A. , Leong J.V., Mezzomo P., Sebek P., Koutecký P., Kukla J., Nguyen P., Moos M., Pokorny V.,  Wagner N.D., Frouz J., van Dam N.M.,  Volf M.,  (2025) Effects of hybridization on chemical diversity and plant-insect herbivore interactions in Salix alba × fragilis, Journal of Experimental Botany, eraf296, https://doi.org/10.1093/jxb/eraf296