Sporothrix zhejiangensis Wang & Lu

Wang, HuiMin, Lun, YingYing, Lu, Quan, Liu, HuiXiang, Decock, Cony & Zhang, XingYao, 2018, Ophiostomatoid fungi associated with pines infected by Bursaphelenchusxylophilus and Monochamusalternatus in China, including three new species, MycoKeys 39, pp. 1-27 : 1

Sporothrix zhejiangensis Wang & Lu sp. nov. Figure 2

Etymology.

The epithet reflects Zhejiang Province in China where the species was first collected.

Type.

CHINA, Zhejiang, Yuyao City, from Monochamus alternatus gallery in Pinus massoniana infested by numerous PWN, November 2012, collected by Q Lu and YY Lun, culture ex-holotype MUCL 55183 = CFCC52165 = CXY1614.

Description.

Sexual morph perithecial: Perithecia occasional on 2% MEA, emerging from the superficial mycelium or partly iμmersed, with a globose base, (75 –)80–108(– 120) μm in diameter, with some basal hyphal ornamentation, black; extending progressively into a straight, brown to black neck, (127 –)156–550(– 631) μm long, (26 –)32–58.5(– 65) μm wide at the base, (7 –)7.5–10.7(– 12) μm wide at the apex; ending in a crown of hyaline, (6 –)9–19.5(– 24) μm long ostiolar hyphae; ascospores reniform in side view, without sheath, aseptate, hyaline, (2 –)2.2–3.4(– 4) × (0.6 –)0.74–2(– 2.5) μm.

Asexual morph: pesotum-like and sporothrix-like.

Pesotum-like: Conidiophores macronematous, synnematous, abundant in 2% MEA. Synnemata occurring singly, enlarging towards both the apex and the base, dark brown at base, becoming paler toward the apex, (100 –)120–260(– 290) μm long including the conidiogenous apparatus, (56 –)63–145(– 158) μm wide at base, rhizoids present; conidiogenous cells (7 –)9.5–29(– 45.5) × 1 –2(– 1.7) μm; conidia hyaline, aseptate, single-celled, smooth, cylindrical or obovoid, (2 –)2.5–4.8(– 6) × (0.5 –)0.8–2.1(– 2.6) μm.

Sporothrix -like: Conidiophores micronematous, single on aerial mycelia, unbranched, (4.5 –)9.6–31.5(– 51.5) × (1.0 –)1.5–2(– 2.4) μm; conidia hyaline, smooth, aseptate, ellipsoid to ovoid, (2.5 –)3–4.8(– 5) × (0.7 –)1–2.1(– 2.5) μm.

Culture characteristics.

Colonies on 2% MEA medium are white, with colony edge thinning radially. Hyphae are superficial on agar. Diameter reaches 50 μm in the dark after 8 d at 25 °C, able to grow at 5 °C and 40 °C, with the optimal growth temperature of 30 °C. Growth characteristics on PDA medium are similar.

Habitat and distribution.

Galleries of Monochamus alternatus in Pinus massoniana infested by PWN; known hitherto from Zhejiang Province, China.

Additional specimens examined.

CHINA, Zhejiang, Yuyao City, from Monochamus alternatus galleries in Pinus massoniana infested by PWN, November 2012, collected by Q Lu and YY Lun, MUCL 55181 = CFCC 52167 = CXY1612, MUCL 55182 = CFCC 52164 = CXY1613, MUCL 55184 = CFCC 52166 = CXY1615.

Note.

Sporothrix zhejiangensis is characterised by a sexual and two asexual forms (pesotum-like and sporothrix-like). It is phylogenetically related to S. nebulare , S. eucalyptigena and S. epigloea (Figure 1). Sporothrix zhejiangensis differs from S. nebulare in both ascomatal and conidial features. The perithecial neck of S. nebulare is shorter than that of S. zhejiangensis , respectively (140 –)169–293(– 365) μm and (127 –)156–550(– 631) μm. The conidia of S. nebulare also are smaller than those of S. zhejiangensis , mostly respectively 2.9-3.7 × 1.1-1.3 μm and 3-4.8 × 1-2.1 μm ( Romón et al. 1900).

Sporothrix eucalyptigena and S. epigloea produce perithecia and ascospores similar to those of S. zhejiangensis ( Crous et al. 2015, Upadhyay 1981). However, S. eucalyptigena has a slightly wider neck than S. zhejiangensis (20-35 vs. 9-19.5 μm) and longer ostiolar hyphae. Furthermore, S. eucalyptigena and S. epigloea only produce a sporothrix-like asexual state and their conidia differ from those of S. zhejiangensis either in size or in shape. Sporothrix eucalyptigena has drop-shaped (lacrymoid) conidia, differing from the ellipsoid to ovoid conidia in S. zhejiangensis . Conidia of S. epigloea are larger than those of S. zhejiangensis (2.5-9 × 1-3.5 vs. 3-4.8 × 1-2.1 μm) ( Crous et al. 2015). Another conspicuous difference between S. zhejiangensis and S. eucalyptigena is the growth rate; the former grows much faster than the latter (50 μm in 8 d vs. 50 μm in 30 d at 25 °C) ( Upadhyay 1981).

Sporothrix zhejiangensis is also closely related to S. bragantina and S. thermara (Figure 1) ( Pfenning and Oberwinkler 1993, de Beer et al. 2016). These three species display the same optimal growth temperature (30 °C) and a similar conidial shape (ellipsoid to obovoid) of their sporothrix-like morph. However, the perithecial base of S. bragantina is larger than that of S. zhejiangensis [globose base: 130-220 μm vs. (75 –)80–108(– 120) μm and the neck also is longer, 700-1200 μm vs. (127 –)156–550(– 631) μm]. The sporothrix-like conidia of S. bragantina also are larger than those of S. zhejiangensis (4-6 × 2-2.5 μm vs. 3-4.8 × 1-2.1 μm). Sporothrix thermara , hitherto, has no known sexual state. It only known by sporothrix-like state; conidia of S. thermara are larger than those of S. zhejiangensis (4-6 × 2-3 μm vs. 3-4.8 × 1-2.1 μm).