New record of ectomycorrhizal association of the genus Nothojafnea in the Northern Hemisphere.

Nothojafnea is recognized as an ectomycorrhizal (ECM) fungal genus currently comprising only two species, both previously reported exclusively from the Southern Hemisphere. Although this genus has been taxonomically recognized, detailed descriptions of its ECM morphology and anatomical characteristics have remained limited and, in some cases, ambiguous. Simultaneously, molecular data for this genus deposited in the NCBI database are still quite limited, with a substantial proportion consisting of unpublished sequences. In this study, we report the first occurrence of Nothojafnea in Vietnam, based on ECM root tip samples obtained from symbiotic associations with 6-month-old Pinus kesiya seedlings. The identification was supported by an integrated approach combining detailed morphological characterization of ECM structures with multilocus phylogenetic analyses using ITS and LSU sequence data. These findings provide new insights into the diversity and biogeography of this genus, significantly extending its known distribution into Southeast Asia.