Soil-borne phytopathogenic fungi in miombo and mopane woodlands of semi-arid Zimbabwe

Soil-borne phytopathogenic fungi play a critical role in forest ecosystem dynamics, influencing plant health, species composition and regeneration processes. However, their diversity and ecological roles remain poorly understood in native forest ecosystems of sub-Saharan Africa, particularly within miombo and mopane woodlands. This study employed high-throughput DNA metabarcoding of the internal transcribed spacer (ITS) region to profile fungal taxa with known phytopathogenic affiliations present in topsoil samples collected from representative mopane and miombo woodlands in semi-arid regions of Zimbabwe. A total of 230 operational taxonomic units were identified, including several genera known to harbour major plant pathogens, such as Fusarium and Ganoderma. Given the ITS-based approach, taxonomic assignments were primarily interpreted at higher taxonomic levels, and species- level identifications were treated with caution. Community composition varied between woodland types, with miombo soils exhibiting higher fungal richness compared to mopane. These findings highlight the potential role of forest soils as reservoirs for fungal taxa with phytopathogenic potential, while also recognising that their presence in native ecosystems does not necessarily imply active disease. This study represents one of the first applications of DNA metabarcoding to assess soil associated phytopathogen diversity in Zimbabwe’s indigenous forests and contributes to a broader understanding of forest health, with relevance for future forest disease surveillance.