Pollination success of Fraxinus excelsior L. in the context of ash dieback

Abstract Key message Paternity analyses show that effective pollination of ash ( Fraxinus excelsior L.) in a seed orchard and floodplain forest affected by dieback is more likely to be facilitated healthier males. Thereby, natural selection can have positive effect on the health future generations. Context Ongoing increasing fragmentation populations may result reduced pollen flow, which reduce success generations trees. Therefore, it essential further improve our understanding gene flow patterns, especially with respect dieback. Aims In this study, paternity were conducted Germany 2018 explain relationship between status trees distances transport. Methods Cambium samples (i.e., from twigs stumps) collected 251 (putative father mother trees) for genotyping, each tree was documented using scoring system evaluate vitality. Additionally, seeds harvested 12 per site. Genetic nuclear microsatellites performed determine paternal Paternities assigned based likelihood model implemented Cervus 3.0.7 software. Results Our results showed average distance 76 m 166 forest. general, decreased substantially tree. Despite dense cover forest, transported over long (greater than 550 m), suggesting non-local sources also play role pollination. This supported foreign input identified (66.5%). Self-pollination detected only very small extent, thus had no major influence reproduction. addition, both healthy slightly diseased similar mating success. However, not case severely (more 50% crown damage) because few offspring could them. Nevertheless, contrast there significant correlation damage classes orchard. Conclusion Long-distance transport contributes connectivity landscape. fathers greater contribution pollination, potentially improving next generation Moreover, stepping stone necessary ensure impact genetic diversity future.