English
Taxonomic Re-evaluation of the genus Catenulocercospora with the Description of a New Species on Setaria pumila
Jae Sung Lee1, Daseul Lee1, Anbazhagan Mageswari1, Le Dinh Thao1, Donghun Kang1, Frederick Leo Sossah1, Hyeon-Dong Shin2, Seung-Beom Hong1*
1Korean Agricultural Culture Collection, Agricultural Microbiology Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, South Korea
2Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, South Korea
*Corresponding author: Seung-Beom Hong
Email: funguy@korea.kr
Catenulocercospora is a monotypic genus within the family Mycosphaerellaceae, currently comprising only C. fusimaculans. This species has been reported from various Poaceae hosts, and in Korea it was previously reported from Echinochola esculenta under the name Cercospora fusimaculans. However, this genus remains poorly understood, as molecular data are scarce, and its true diversity is also underestimated. To investigate the potential diversity within the genus, we re-evaluated cercosporoid fungal strains isolated from Poaceae hosts and preserved in the Korean Agricultural Culture Collection (KACC). Morphological characteristics were examined using light microscopy, and multi-gene phylogenetic analyses were performed using ITS, LSU, ACT, and TEF sequences. Among the examined strains, one isolate from Setaria pumila was morphologically consistent with the genus Catenulocercospora, but formed a distinct and well-supported lineage separate from C. fusimaculans in the multi-gene phylogenetic analysis. Although morphologically indistinguishable, the genetic divergence across all loci supports the recognition of this strain as a novel species. This study introduces a new species of Catenulocercospora and highlights the importance of re-evaluating legacy fungal isolates using integrative taxonomic approaches to uncover cryptic diversity within cercosporoid fungi. This finding provides new insights into the diversity of Catenulocercospora and emphasizes the importance of re-examining morphologically conserved fungal genera using multi-gene data.
