Sporothrix villosa R.L. Chang & X.Y. Zhang, 2021

Chang, Runlei, Zhang, Xiuyu, Si, Hongli, Zhao, Guoyan, Yuan, Xiaowen, Liu, Tengteng, Bose, Tanay & Dai, Meixue, 2021, Ophiostomatoid species associated with pine trees (Pinus spp.) infested by Cryphalus piceae from eastern China, including five new species, MycoKeys 83, pp. 181-208 : 181

7. Sporothrix villosa R.L. Chang & X.Y. Zhang sp. nov.

Fig. 13

Holotype.

China. Shandong province: Zhujiajuan village, Huancui District, Weihai City, from Cryphalus piceae on Pinus thunbergii , 10 Oct. 2019, R. L. Chang (HMAS 249926-holotype; SNM188 = CGMCC 3.20264- ex-holotype culture).

Additional cultures checked.

China. Shandong province: Zhujiajuan village, Huancui District, Weihai City, from Cryphalus piceae on Pinus thunbergii , 10 Oct. 2019, R. L. Chang (SNM162); China. Shandong province: Zhujiajuan village, Huancui District, Weihai City, from Cryphalus piceae on Pinus thunbergii , 10 Oct. 2019, R. L. Chang (SNM182).

Etymology.

The name refers to the velvety colony morphology of this fungus on MEA.

Diagnosis.

Sporothrix villosa differ from S. abietina by the production of smaller conidia and slow growth rate on MEA at 35 °C.

Description.

Sexual morph is unknown. Asexual state sporothrix-like: the conidiophores directly arising from the vegetative hyphae, measuring (3.2-) 6.8-23.8 (-53.6) μm × (0.5-) 0.8-1.3 (-1.5) μm (Fig. 13b, d and e ); conidia hyaline, smooth, unicellular oblong to ovoid, with rounded ends, measuring (1.2-) 1.8-2.6 (-4.1) × (0.7-) 0.8-1.1 (-1.4) μm (Fig. 13c ).

Culture characteristics.

The colonies are white in color on MEA. Mycelia were submerged in the agar. The optimal temperature for growth is 25 °C, reaching 21.1 mm diam in 10 d. Growth is extremely slow at 35°C 3 mm diam in 10 days. No growth was observed at 5 °C.

Distribution.

Currently known from Weihai City in Shandong Province, China.

Note.

Sporothrix villosa is closely related to two fungal isolates recovered from China in CAL tree, and another two isolates recovered from the USA in ITS and BT trees, which were previously identified as S. cf. abietina . This taxon is phylogenetically distinct from all other species in the S. gossypina species complex (Figs 6 - 8 ). Six et al. (2011) classified all the isolates from China, Canada, the USA, New Zealand, Korea, and South Africa that were close to the ex-type cultures on the BT tree as S. abietina . However, these selected isolates did not form a monophyletic clade. Later, in the phylogenies using BT and CAL gene-regions, these isolates of S. abietina did not cluster with the ex-type isolates of S. abietina . Therefore, these isolates were provisionally identified as S. cf. abietina ( Romón et al. 2014a; Romón et al. 2014b). Our phylogenetic analyses indicated that isolates classified as S. abietina ( Six et al. 2011) plausibly included several phylogenetic distinct species. In this study, Sporothrix villosa recovered produced a sporothrix-like asexual morph similar to other species in the complex. Furthermore, the conidia of S. villosa (Fig. 13c ) are smaller than those of S. abietina (1.2-4.1 × 0.7-1.4 vs. 4-7.5 × 1-2 μm) ( Marmolejo and Butin 1990). Unlike S. abietina , S. villosa can grow slowly at 35 °C.

Figures

Figure 6. Maximum likelihood phylogeny of Sporothrix gossypina species complex using complete ITS region. The isolates recovered in this study are highlighted in color and in bold font. ML and MP bootstrap support values ≥ 75 are indicated at the nodes as ML / MP. Bold branches indicate posterior probabilities values ≥ 0.9. T indicates ex-type cultures.

Figure 8. Maximum likelihood phylogeny of Sporothrix gossypina species complex using partial CAL gene region. The isolates recovered in this study are highlighted in color and in bold font. ML and MP bootstrap support values ≥ 75 are indicated at the nodes as ML / MP. Bold branches indicate posterior probabilities values ≥ 0.9. T indicates ex-type cultures.

Figure 13. Morphological characters of asexual structures of Sporothrix villosa sp. nov. a fourteen-day-old culture on MEA b-e conidiophores and conidia. - Scale bars: 10 μm.