Sporothrix macroconidia H. Wang, Q. Lu & Z. Zhang

Min Wang, Hui, Wang, Zheng, Liu, Fu, Xu Wu, Cheng, Fang Zhang, Su, Kong, Xiang Bo, Decock, Cony, Lu, Quan & Zhang, Zhen, 2019, Differential patterns of ophiostomatoid fungal communities associated with three sympatric Tomicus species infesting pines in south-western China, with a description of four new species, MycoKeys 50, pp. 93-133 : 112-113

Sporothrix macroconidia H. Wang, Q. Lu & Z. Zhang sp. n. Fig. 15

Etymology.

‘macroconidia’ (Latin), referring to the large conidia of this fungus.

Type.

CHINA, Yunnan, from Tomicus yunnanensis galleries in Pinus yunnanensis , Dec. 2016, collected by HM Wang, holotype CXY 1894, culture ex-holotype CFCC 52628 = CXY 1894.

Description.

Sexual form: unknown.

Asexual form: Sporothrix -like. Conidiophores semi-macronematous, mononematous; conidiogenous cells hyaline, simple or loosely branched, thin-walled, aseptate, bearing denticles forming a rachis (4.1-) 11.0-24.5 (-36.5) × (1.4-) 2.1-3.4 (-4.9) μm; conidia hyaline, cylindrical, ellipsoid to ovoid, 1-celled, smooth, (3.6-) 4.8-7.4 (-9.9) × (2.5-) 3.2-4.9 (-9.9) μm, solitarily or aggregating in slimy masses.

Culture characteristics.

Colonies on 2% MEA medium slow growing in the dark, reaching 34 mm in diam. in 8 days at 25 °C, growth rate up to 5 mm/day at the fastest; colony margin smooth. Hyphae appressed to flocculose, white; reverse hyaline to pale yellowish. Optimal growth temperature 25 °C, little growth at 5 °C and 35 °C.

Known substrates and hosts.

Galleries of Tomicus yunnanensis and T. brevipilosus in Pinus yunnanensis and P. kesiya .

Known insect vectors.

Tomicus yunnanensis , T. brevipilosus .

Known distribution.

Yunnan Province, China.

Additional specimens examined.

CHINA, Yunnan, from Tomicus brevipilosus galleries in Pinus kesiya , Dec. 2016, Jan. 2017, HM Wang, CFCC 52629 = CXY 1895, CFCC 52630 = CXY 1896.

Note.

Sporothrix macroconidia is closely related to O. valdivianum , S. bragantina , S. brunneoviolacea and S. fumea in phylogenetic analyses inferred from LSU, ITS, TUB2 and CAL DNA sequence data. It differs from these species by its conidia, which are larger than those of the other four species, mostly 4.8-7.4 × 3.2-4.9 μm and 4-6 × 2 μm in O. valdivianum ( Butin and Aquilar 1984), 4-6 × 2-2.5 μm in S. bragantina ( Pfenning and Oberwinkler 1993), 3-7 × 1.5-3 μm in S. brunneoviolacea ( Madrid et al. 2010) and 1.5-2.0 × 0.5-1.0 μm in S. fumea ( Nkuekam et al. 2012). In addition, a sexual state was observed in vitro for O. valdivianum , S. bragantina and S. fumea , which was not observed in S. macroconidia and S. brunneoviolacea .

Sporothrix macroconidia was found associated with T. yunnanensis infesting P. yunnanensis and with T. brevipilosus infesting P. kesiya . The other four similar species have very different ecology and known geographic distributions. Sporothrix fumea was isolated from Eucalyptus cloeziana infested by Phoracantha beetles in South Africa ( Nkuekam et al. 2012), whereas O. valdivianum , S. bragantina and S. brunneoviolacea were obtained from soil or Nothofagus in Europe and South America ( Butin and Aquilar 1984, Pfenning and Oberwinkler 1993, Madrid et al. 2010).