Morpho-anatomical and molecular characterization of Isoberlinia doka ectomycorrhizal morphotypes in the Sudanian woodlands

Abstract Despite the ecological importance of Isoberlinia doka in the Sudanian woodlands of West Africa, its ectomycorrhizal (EcM) status and associated fungal community remain poorly documented. Here, we assessed the ectomycorrhizal status of I. doka and characterized its associated ectomycorrhizal morphotypes using an integrative morpho-anatomical and molecular approach. Fine roots were sampled from 12 forest reserves across the Sudanian and Sudano-Guinean climatic zones of Benin. Ectomycorrhizal root tips were identified microscopically, grouped into morphotypes based on standardized descriptive criteria, and taxonomically assigned using Sanger sequencing by targeting the internal transcribed spacer (ITS) region. Overall, 52.8% of the root samples were colonized by ectomycorrhizal fungi, confirming that I. doka consistently forms ectomycorrhizal associations in its natural range. However, colonization differed markedly between climatic zones, reaching 77.8% in the more humid Sudano-Guinean zone but only 27.8% in the drier Sudanian zone. Sixteen distinct ectomycorrhizal morphotypes were recognized, including Russulales , Thelephorales , Agaricales, Sebacinales and Boletales , with affinities to the genera Lactifluus , Russula , Thelephora , Amanita , Scleroderma , Sebacina and Inocybe . This study provides the first reference dataset for I. doka in Benin and offers a baseline for selecting locally adapted fungal inocula to support woodland restoration and regeneration under increasing seasonal drought.