Morphological and multilocus phylogenetic analyses reveal three endophytic Nigrospora species from fresh leaves of sandalwood (Santalum album L.) in Yunnan, China

Endophytic fungi are an important component of microbial diversity in plant ecosystems and have substantial potential for ecological and biotechnological applications. This study reports Nigrospora species associated with Santalum album (white sandalwood) in Yunnan Province, China. Endophytic fungi were isolated from fresh leaves of S. album and identified based on morphological characteristics and DNA sequence data from three loci: the internal transcribed spacer region (ITS), partial translation elongation factor 1-α (tef1-α), and partial β-tubulin (tub2) genes. Based on morphological characterization and multilocus phylogenetic analyses of a concatenated ITS, tef1-α, and tub2 dataset, three Nigrospora species were identified, namely Nigrospora lacticolonia, N. shadeganensis, and N. sphaerica. These three species are reported for the first time as endophytes associated with S. album. These findings expand the known host range of the genus Nigrospora, enrich our understanding of its taxonomic and ecological diversity, and provide new insights into the diversity of endophytic fungi associated with sandalwood, a commercially and ecologically valuable tree species.