Morpho-Molecular Approach Reveals Three Novel Cladosporium Species Associated with Camellia sinensis cv. Fenghuang Dancong in China

The genus Cladosporium represents one of the largest genera of dematiaceous hyphomycetes, which are commonly found on plants. The species comprising this group predominantly function as plant endophytes, producing important bioactive compounds, or act as pathogens damaging crops of significant economic interest. Nevertheless, their association with Camellia spp. remains to be fully elucidated, with only seven recorded cases mentioning three known species. During an investigation into fungi associated with tea plant, several Cladosporium isolates were obtained from symptomatic leaves of Camellia sinensis cv. Fenghuang Dancong. Using a polyphasic approach that combined morphological observations with multi-locus phylogenetic analyses based on the internal transcribed spacer (ITS), actin (act), and translation elongation factor 1-α (tef1-α), these isolates were identified as three new species in the C. cladosporioides complex, namely C. dancongensis sp. nov., C. fenghuangensis sp. nov., and C. leptosporum sp. nov. These new species can be distinguished from their close relatives (e.g., C. benschiae, C. dracaenae, C. kuwanaspidi, and C. tenuissimum) by distinct morphological features such as conidial dimensions, mycelial width, and colony characteristics. This study expands the understanding of fungi associated with Camellia sinensis and is the first case in which new Cladosporium species inhabit tea plants. Moreover, it will facilitate further research into the phylogenetic relationships of these new species and their role relative to tea plant disease.