Pseudocercospora cunninghamia Y. Zhang, Z.C. Liu & Z.P. Dou [as ‘cunninghamia’], in Cao et al., Fungal Diversity 132: 434 (2025)

Index Fungorum number: IF 859557; MycoBank number: MB 856943; Facesoffungi number: FoF 17087; Figs. 1, 2

Etymology – Refers to the host Cunninghamia lanceolata.

Holotype – BJFC LZC160120-57.

Needle leaves 3/4 wilted to fully wilted, sometimes a small branch of needles fully wilted, eventually turning brown. Primary mycelia within the substrate, secondary mycelium on the surface, subhyaline to pale brown, separated, branched, 3.0–5.0 µm wide. Caespituli amphigenous, punctiform, scattered, grayish-white to gray, mostly located on the underside of the leaves. Pustule pale brown, subspherical to spherical, 25.0–122.0 µm diam. Conidiophores tightly clustered, pale brown, occasionally with simple branched, upper part bluntly rounded or sometimes flexuous, 1–3 septate, 25.0–40.0 × 2.0–4.0 µm.
Conidiogenous cells integrated, terminal or conidiophores reduced to conidiogenous cells, pale brown, unbranched, 12.0–20.0 × 3.0–4.0 µm, smooth, tapering to flat-tipped apical loci, unthickened, not darkened. Conidia solitary, narrowly subcylindrical, subhyaline to pale brown, apex rounded and obtuse, base nearly truncate to truncate, slightly thickened at the base, 0–7-septate, 23.0–75.0 × 2.0–3.0 µm.

Material examined – CHINA, Guangdong Province, Guangzhou City, South China Botanical Garden, Chinese Academy of Sciences, on needle leaves of Cunninghamia lanceolata, 23°18’N 113°37’E, 22 m asl, 20 Jan 2016, Ying Zhang, Zu-Chen Liu, Zhi-Peng Dou, BJFC LZC160120-57 (holotype) and BJFC LZC160120-58.

GenBank – BJFC LZC160120-57: MH059728 (ITS), MH153937 (tef1), MH153896 (act), MH153850 (rpb2).

Notes – Pseudocercospora cunninghamia infects the needles of Cunninghamia lanceolata. Pseudocercospora is significantly affected by host range (Crous 2013). Except for this study, Pseudocercospora has not been known to infect hosts of Taxodiaceae to date. Phylogenetic analysis showed that Pseudocercospora cunninghamia (BJFC LZC160120-57) differs from P. securinegae (CPC10793) by unique fixed alleles in three loci based on alignments of the separate loci deposited in the tree, by 4-bp in ITS (0.9%), 9-bp in tef1 (3.5%) and 4 bp in act (2.7%). Morphologically, conidia of P. securinegae is hyaline, 2–7 septate, and spores larger than Pseudocercospora cunninghamia (3–4 × 25–l25 µm) (Deighton 1976). All the above reveal that Pseudocercospora cunninghamia is a new species.

Figure 1 – Pseudocercospora cunninghamia (BJFC LZC160120-57, holotype). a Leaf spots on upper and lower leaf surface. b Close-up of leaf spot with fruiting. c–f Fascicles with conidiophores and conidiogenous cells. g–h Conidia. Scale bars = 10 µm.

Figure 2 – Phylogenetic tree inferred from Maximum Likelihood analysis of Pseudocercospora based on a combined dataset of ITS, tef1, act, and rpb2 genes. The outgroup taxon is Passalora eucalypti (CBS 111318). Support values are indicated at the nodes as follows: Maximum Likelihood bootstrap (ML = 50%), Bayesian posterior probability (PP = 0.90), and Maximum Parsimony bootstrap (MP = 50%) (ML/PP/MP). The scale bar represents 0.02 substitutions per site.