Verifying the origin of forest reproductive material using genetic fingerprinting: development of an operational framework

Ensuring the traceability of forest reproductive material (FRM) is a crucial step for establishing resilient forests under accelerating climate change. To address this need, we developed and implemented a standardized genetic fingerprinting workflow for nine important forest tree species enabling the verification of the origin of commercial seed lots and nursery plantlets. The method is based on reference samples (cones or seeds) collected from each individual tree during seed harvesting, as mandated by the Austrian Act and Regulation on FRM. For each species, eight to nine highly polymorphic nuclear microsatellite loci were selected, and laboratory protocols were optimized and validated on various types of plant tissue from mother trees including cone scales, testa, and pericarp as well as on offspring samples with known maternal origin. Subsequently parentage analyses of seed lots and nursery plants demonstrated that 72 to 86% of samples could be successfully assigned to their respective mother trees. Assignment success was strongly influenced by the quality of maternal tissue and completeness of the reference collection. The workflow also enabled the detection of duplicate submissions among reference mother samples, providing an independent verification of compliance with minimum number of tree harvesting requirements. Collectively, these results establish a robust and operational framework for DNA-based verification of FRM origin and highlight its potential to enhance transparency and quality assurance throughout FRM supply chains.