NeoBiota 65: 109–136 (2021) A peer-reviewed open-access journal doi: 10.3897/neobiota.65.64031 RESEARCH ARTICLE NeoBiota https://neobiota.pensoft.net Advancing research on alien species and biological invasions Genic introgression from an invasive exotic fungal forest pathogen increases the establishment potential of a sibling native pathogen Fabiano Sillo1,2*, Matteo Garbelotto3*, Luana Giordano1, Paolo Gonthier1 1 University of Torino, Department of Agricultural, Forest and Food Sciences (DISAFA), Largo Paolo Braccini 2, I-10095 Grugliasco, Italy 2 National Research Council - Institute for Sustainable Plant Protection (CNR- IPSP), Viale P.A. Mattioli 25, I-10125 Torino, Italy 3 University of California, Berkeley, Department of Environmental Science, Policy and Management, Forest Pathology and Mycology Laboratory, 54 Mulford Hall, 94720 Berkeley, California, USA Corresponding author: Paolo Gonthier (
[email protected]) Academic editor: M. Uliano-Silva | Received 8 February 2021 | Accepted 5 May 2021 | Published 28 May 2021 Citation: Sillo F, Garbelotto M, Giordano L, Gonthier P (2021) Genic introgression from an invasive exotic fungal forest pathogen increases the establishment potential of a sibling native pathogen. NeoBiota 65: 109–136. https://doi. org/10.3897/neobiota.65.64031 Abstract Significant hybridization between the invasive North American fungal plant pathogenHeterobasidion irreg- ulare and its Eurasian sister species H. annosum is ongoing in Italy. Whole genomes of nine natural hybrids were sequenced, assembled and compared with those of three genotypes each of the two parental species. Genetic relationships among hybrids and their level of admixture were determined. A multi-approach pipe- line was used to assign introgressed genomic blocks to each of the two species.