Colletotrichum berchemiae S. X. Zhou, sp. nov.
Creators: name: Zhou, Si-Xuan
name: Bao, Dan-Feng
name: Zhang, Tao
name: Xiao, Yuan-Pin
name: Tang, Yuan-Jiang
name: Jing, Zhang
name: Lu, Yu-Xi
name: Shi, Kai-Zhi
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Botryosphaeriales
Botryosphaeriaceae
Colletotrichum
Colletotrichum berchemiae

description: Colletotrichum berchemiae S.X. Zhou sp. nov.   
Index Fungorum number: IF 900643; Facesoffungi number: FoF 15294; FIGURE. 1  
 Etymology: Referring to the host plant Berchemia polyphylla var. leioclada, on which the holotype was collected.   
Holotype: KUN-HKAS 131984  
 Endophytic in fresh leaves of Berchemia polyphylla var. leioclada. Sexual morph: not observed. Asexual morph: Vegetative hyphae hyaline or pale brown, smooth-walled, septate, branched. Setae absent. Conidiomata acervular, gregarious, paleluteous. Chlamydospores not observed. Conidiophores 20–30 × 3–4(–5) µm (x = 25.3 × 3.9 μm, n = 25), formed directly on hyphae, cylindrical, hyaline, becoming brown to dark brown after maturity, hyaline to pale brown towards the apex, brown to dark brown at the base, branched, septate, smooth-walled. Conidiogenous cells 7–15 × 3–4.5 µm (x = 10.8 × 3.9 μm, n = 25), phialidic, integrated, terminal, hyaline, smooth-walled, cylindrical to clavate. Conidia 13–16 × 3.5–4.5 µm (x = 14.4 × 4.1μm, n = 40), hyaline, aseptate, guttulate, dry, cylindrical, rounded at both ends, or one end obtuse and another end round, straight or slightly curved, smooth-walled. Appressoria: not observed.   
Cultural characteristics: Colonies on PDA reaching 68–70 mm diam, flat, entire margin, with black spots on the surface, grey on the surface, brown to dark grey on reverse, without pigmentation.  
 Material examined: CHINA, Guizhou Province, from Berchemia polyphylla var. leioclada leaves, 27 June 2022, S.X. Zhou, B11G1-1 (KUN-HKAS 131984, holotype), ex-type culture GMBCC 20001.   
GenBank numbers: ITS = PP049021, ACT = PP056098, CHS-1 = PP056099, GAPDH = PP056100, TUB2 = PP056101.  
 Notes: In our multi-locus (ITS, ACT, CHS-1, GADPH, and TUB2) phylogenetic analyses, our new isolate Colletotrichum berchemiae formed a distinct lineage basal to C. gloeosporioides species complex (FIGURES. 2, S 1). Colletotrichum berchemiae is similar to the C. gloeosporioides species complex in having cylindrical conidia (Weir et al. 2012). However, considering the ingroup taxa of the C. gloeosporioides species complex are much more closely related to each other than to C. gloeosporioides. In addition, the PHI test revealed no significant recombination event between C. gloeosporioides and the closely related taxa (Φw = 0.42) (Figure 3). Thus, we identified our species as singleton species.   
 Morphologically, C. berchemiae is similar to C. pyrifolia in having hyaline to pale brown, smooth-walled, septate and branched conidiophores, hyaline to pale brown, cylindrical to clavate conidiogenous cells and hyaline, smooth-walled, aseptate, cylindrical conidia. However, C. berchemiae is different from C. pyrifolia in having smaller conidiogenous cells (7–15 × 3–5 vs. 15–32 × 3–5 µm) and conidia (13–16 × 3–5 vs. 14–23 × 5.5–7 um). In addition, the conidia of C. berchemiae are rounded at both ends or one end obtuse and another end round. Whereas, conidia of C. pyrifolia are cylindrical with round ends (Fu et al. 2019). Colletotrichum berchemiae can be distinguished from C. arecacearum in having hyaline to pale brown, smooth-walled, septate and branched conidiophores and hyaline to pale brown conidiogenous cells. In contrast, the conidiophores of C. arecacearum are reduced to conidiogenous cells, and conidiogenous cells are hyaline (Liu et al. 2022).
description: Published as part of Zhou, Si-Xuan, Bao, Dan-Feng, Zhang, Tao, Xiao, Yuan-Pin, Tang, Yuan-Jiang, Jing, Zhang, Lu, Yu-Xi & Shi, Kai-Zhi, 2024, Two new endophytic fungi of Colletotrichum and Diaporthe isolated from Berchemia polyphylla var. leioclada in Guizhou Province, China, pp. 1-15 in Phytotaxa 640 (1) on pages 4-7, DOI: 10.11646/phytotaxa.640.1.1, http://zenodo.org/record/13213342