Population structure and diversity of the needle pathogen Dothistroma pini suggests human-mediated movement in Europe

Ariska van der Nest; Michael J Wingfield; Dušan Sadiković; Martin S Mullett; Benoit Marçais; Valentin Queloz; Katarina Adamčíková; Kateryna Davydenko; Irene Barnes

doi:10.3389/fgene.2023.1103331

Population structure and diversity of the needle pathogen Dothistroma pini suggests human-mediated movement in Europe

Front Genet. 2023 Feb 16:14:1103331. doi: 10.3389/fgene.2023.1103331. eCollection 2023.

Authors

Affiliations

¹ Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
² Slovenian Forestry Institute, Ljubljana, Slovenia.
³ Southern Swedish Forest Research Centre, Swedish University of Agricultural Science, Alnarp, Sweden.
⁴ Phytophthora Research Centre, Mendel University in Brno, Brno, Czechia.
⁵ Université de Lorraine, INRAE-Grand-Est, UMR1136 Interactions Arbres, Microorganismes, Nancy, France.
⁶ Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
⁷ Institute of Forest Ecology Slovak Academy of Sciences, Department of Plant Pathology and Mycology, Nitra, Slovakia.
⁸ Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Science, Uppsala, Sweden.
⁹ Ukrainian Forest Research Institute, Forestry and Forest Melioration, Kharkiv, Ukraine, Slovakia.

Abstract

Dothistroma needle blight (DNB) is an important disease of Pinus species that can be caused by one of two distinct but closely related pathogens; Dothistroma septosporum and Dothistroma pini. Dothistroma septosporum has a wide geographic distribution and is relatively well-known. In contrast, D. pini is known only from the United States and Europe, and there is a distinct lack of knowledge regarding its population structure and genetic diversity. The recent development of 16 microsatellite markers for D. pini provided an opportunity to investigate the diversity, structure, and mode of reproduction for populations collected over a period of 12 years, on eight different hosts in Europe. In total, 345 isolates from Belgium, the Czech Republic, France, Hungary, Romania, Western Russia, Serbia, Slovakia, Slovenia, Spain, Switzerland, and Ukraine were screened using microsatellite and species-specific mating type markers. A total of 109 unique multilocus haplotypes were identified and structure analyses suggested that the populations are influenced by location rather than host species. Populations from France and Spain displayed the highest levels of genetic diversity followed by the population in Ukraine. Both mating types were detected in most countries, with the exception of Hungary, Russia and Slovenia. Evidence for sexual recombination was supported only in the population from Spain. The observed population structure and several shared haplotypes between non-bordering countries provides good evidence that the movement of D. pini in Europe has been strongly influenced by human activity in Europe.

Keywords: Dothistroma needle blight; Dothistroma pini; Mycosphaerella pini; mating types; microsatellites; pine needle pathogen; red band needle blight.

Grants and funding

Financial support for this study was provided by the University of Pretoria, members of the Tree Protection Cooperative Program (TPCP), the National Research Foundation (Thuthuka Grant no 80670, and Grant no 95875), a Scarce Skills Doctoral Scholarship (Grant 89086) for A. van der Nest, and DIAROD: EU COST Action FP1102 DIAROD (Determining Invasiveness and Risk of Dothistroma, https://www.cost.eu/actions/FP1102/). The NRF acknowledge that opinions, findings, conclusions and/or recommendations expressed in any publication generated by the NRF supported research are that of the author (s), and that the NRF accepts no liability whatsoever in this regard. The NRF had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.