Colletotrichum quercicola Ning Jiang & C.B. Wang, 2022

Wang, Cheng-Bin, Jiang, Ning, Xue, Han, Piao, Chun-Gen & Li, Yong, 2022, Colletotrichum chinense sp. nov. from Yucca gloriosa and C. quercicola sp. nov. from Quercus variabilis in China, MycoKeys 93, pp. 1-21 : 1

Colletotrichum quercicola Ning Jiang & C.B. Wang sp. nov.

Fig. 4

Etymology.

Referring to the host genus, Quercus .

Description.

Sexual morph not observed. Asexual morph developed on PDA. Chlamydospores not observed. Conidiomata acervular, abundant, globose to pulvinate, 200-400 μm diam. Conidiophores, hyaline, branched, smooth-walled, up to 50 μm long. Setae medium brown, smooth-walled, 60-145 μm long, 1-3-septate. Conidiogenous cells 6-18 × 3-7 µm (x - = 7.9 ± 3.6 × 4 ± 1.2 µm, n = 20), hyaline, smooth-walled, cylindrical to elongate ampulliform. Conidia 14.5-23 × 3-5 µm (x - = 17 ± 1.7 × 3.9 ± 0.5 μm, n = 50), L/W ratio =4-5, hyaline, smooth-walled, fusiform, straight to slightly curved with both ends rounded or one end round and the other truncate. Appressoria 6-11 × 4-8 µm (x - = 8.4 ± 1.4 × 5 ± 1 μm, n = 50), L/W ratio = 1.5-2, single, medium brown, smooth-walled, subglobose, ovate to broadly elliptical in outline.

Culture characters.

Colonies on PDA flat, with moderate aerial mycelium, margin white to light gray, gray to brown in the center, reaching 46-50 mm diam in 7 days at 25 °C. Colonies on MEA flat, covered by white aerial mycelium, white margin and light orange in the center, reaching 30-35 mm diam after 7 days at 25 °C. Colonies on SNA flat, with entire margin, covered by sparse white aerial mycelium, reaching 20 mm diam after 7 days at 25 °C.

Specimens examined.

China, Shaanxi Province, Foping County, Dongshan Park, isolated from leaf spot of Quercus variabilis Bl., Yong Li , 11 September 2019 (holotype CAF800057; ex-type living culture: CFCC 54457); Ibid (living culture: CFCC 57507) .

Notes.

Four Colletotrichum species are presently known to occur on Quercus hosts, viz. C. clidemiae, C. gloeosporioides , C. karstii and C. theobromicola ( Weir et al. 2012; Liu et al. 2021). Colletotrichum quercicola can be distinguished from those species based on any of the loci (ITS, gapdh, chs-1, act and tub2) and the fusiform conidia. Colletotrichum quercicola is a member of the Colletotrichum destructivum species complex and near to C. tanaceti. Phylogenetically, this species can be distinguished from C. tanaceti CBS 132693 by 88 nucleotide differences in concatenated alignment (20/560 in ITS, 14/274 in act, 2/280 in chs-1, 17/236 in gapdh, and 33/525 in tub2) ( Damm et al. 2014). Morphologically, C. quercicola CFCC 54457 conidia are straight to slightly curved, differing from distinctly curved conidia in C. tanaceti CBS 132693 ( Damm et al. 2014).

Figures

Figure 4. Colletotrichum quercicola (CFCC 54457; ex-type) A colony on PDA B colony on MEA C colony on SNA D conidiomata formed in PDA E, F conidiophores G, H conidia I appressoria were producing using a slide culture technique E-H from PDA. Scale bars: 200 µm (D); 50 µm (E); 20 µm (F); 10 µm (G-I).