Cladosporium lagenariiforme Wonjun Lee & Y.W. Lim, 2023

Lee, Wonjun, Kim, Ji Seon, Seo, Chang Wan, Lee, Jun Won, Kim, Sung Hyun, Cho, Yoonhee & Lim, Young Woon, 2023, Diversity of Cladosporium (Cladosporiales, Cladosporiaceae) species in marine environments and report on five new species, MycoKeys 98, pp. 87-111 : 87

Cladosporium lagenariiforme Wonjun Lee & Y.W. Lim sp. nov.

Figs 2A , 3A

Typification.

Republic of Korea. Jeju-do, Chuja-myeon, 33°57′11.88″N, 126°18′07.56″E, seaweed, 31 Aug 2021, M.S. Park & Y.W. Lim (holotype SFC20230103-M23, stored in a metabolically inactive state).

Etymology.

The term ' lagenariiforme ' was derived from the generic name of a calabash ( Lagenaria ) to describe the shape of the ramoconidia and secondary ramoconidia.

Description.

Asexual morphology: Mycelium mainly immersed, composed of septate, branched, hyaline, verruculose hyphae, 1.8-4.3 μm wide. Conidiophores macronematous and micronematous, arising laterally from hyphae, sometimes reduced to conidiogenous cells, septate, erect to slightly flexuous, slightly nodulose, branched, up to 208 μm long, 1.7-3 μm wide, pale brown, verrucose. Conidiogenous cells integrated, terminal and intercalary, cylindrical to subcylindrical, 15.1-37.6 × 1.4-2.9 μm, bearing up to four slightly darkened and refractive conidiogenous loci. Ramoconidia 0(-2)-septate, subcylindrical to ellipsoidal, obclavate, sometimes calabash-like constricted at the center, 8.7-26.4 × 1.9-3.5 μm [av. ( ± SD) 15.2 ( ± 5.46) × 2.6 ( ± 0.39)], pale brown, verruculose. Conidia forming branched chains, with up to six conidia in the terminal unbranched part, long neck between conidia, aseptate, pale brown, smooth to verruculose, with protuberant, slightly darkened, and refractive hila. Small terminal conidia aseptate, ellipsoidal, 2.1-3.5 × 1.3-2.3 μm [av. ( ± SD) 3 ( ± 0.32) × 1.9 ( ± 0.22)]. Intercalary conidia aseptate, ellipsoidal to limoniform, 2.9-5.3 × 1.6-2.7 μm [av. ( ± SD) 4.0 ( ± 0.47) × 2.0 ( ± 0.25)]. Secondary ramoconidia 0(-1)-septate, subcylindrical to ellipsoidal, obclavate, sometimes calabash-like constricted at the center, 7.3-21.6 μm long × 2.0-3.7 μm [av. ( ± SD) 13.6 ( ± 4.01) × 2.6 ( ± 0.36)].

Cultural characters: Colonies on PDA 52-70 mm diam after 14 d at 25 °C, greenish gray (1B2) to olive (1E3), reverse dark gray (1F8), floccose, velvety, crateriform, radially furrowed, wrinkled, usually significantly wrinkled in the margin part; margin yellowish gray (4B2) edge, slightly lobate; aerial mycelia abundantly formed, dense, with few exudates, sporulation profuse. Colonies on MEA 46-74 mm diam after 14 d at 25 °C, gray (1C1) to olive gray (1D3), reverse dark gray (1F8), floccose-woolly, umbonate, (frequently) radially furrowed, wrinkled, sometimes significantly wrinkled in the margin part; margin whitish edge, slightly lobate, rarely undulate; aerial mycelia abundantly formed, dense, with prominent exudates, sporulation profuse. Colonies on OA 56-68 mm diam after 14 d at 25 °C, olive yellow (3C8), reverse concolorous, woolly-floccose, raised, radially furrowed; margin yellowish gray (3C2), regular; aerial mycelia abundantly formed, without prominent exudates, sporulation moderate. Colonies on SNA 36-37 mm diam after 14 d at 25 °C, olive yellow (3E8) to olive (3E8), reverse concolorous, powdery, flat; margin yellowish white (2A2), regular; aerial mycelia abundantly formed, without prominent exudates, sporulation profuse.

Habitat and distribution.

Isolated from seaweeds; Southern Korean seaside in Republic of Korea.

Additional cultures examined.

Republic of Korea. Jeju-do, Chuja-myeon, 33°23′53″N, 126°14′24″E, seaweed, 31 Aug 2021, M.S. Park & Y.W. Lim (SFC20230103-M20, stored in a metabolically inactive state); Jeju-do, Chuja-myeon, 33°23′53″N, 126°14′24″E, seaweed, 31 Aug 2021, M.S. Park & Y.W. Lim (SFC20230103-M21, stored in a metabolically inactive state); Jeju-do, Chuja-myeon, 33°23′53″N, 126°14′24″E, seaweed, 31 Aug 2021, M.S. Park & Y.W. Lim (SFC20230103-M22, stored in a metabolically inactive state).

Notes.

Cladosporium lagenariiforme sp. nov. is phylogenetically closely related to C. angulosum and C. xanthochromaticum (Fig. 1 ). Genetic identity between C. lagenariiforme and C. angulosum (CBS 140692), the closest species, shows 93.12% in act and 87.62% in tef1. Cladosporium lagenariiforme and C. angulosum produce up to 6 and 14 conidia in long-branched chains, respectively, which is more than that in C. xanthochromaticum [up to 6(-7)] isolated from indoor environments ( Bensch et al. 2018). The conidiophores of C. lagenariiforme are verrucose, and ramoconidia rarely have up to two septa, compared to that of the two sister species with smooth conidiophores and often aseptate ramoconidia ( Sandoval-Denis et al. 2016). The ramoconidia of C. lagenariiforme are shorter than those of C. angulosum and C. xanthochromaticum (24.5-46 × 2-3.5 μm and 18-36 × 2-3.5 μm, respectively) ( Sandoval-Denis et al. 2016).

Figures

Figure 1. Maximum likelihood (ML) tree of Cladosporium, inferred based on ITS, act, and tef 1 sequences. The values at each node indicate the bootstrap of ML (≥ 70) and the posterior probability (PP; ≥ 0.90) of Bayesian inference (BI) analyses. Thick lines on branches indicate 100 bootstrap and 1.00 PP support. The tree is rooted to Cercospora beticola (CBS 116456). The small tree on the upper left represents the topology of species complexes of the genus. The filled triangles correspond to the species complex (es) shown. The colored circles symbolize habitats where the species were isolated. Previously described species are grouped in gray boxes, and blue boxes indicate new species. Strains with newly generated sequences are in red, with the holotypes in bold. The holotype and epitype for the reference strains are represented with " * " and " ** ", respectively.

Figure 2. Morphological characteristics of the new and unrecorded species on PDA, MEA, OA, and SNA media A Cladosporium lagenariiforme sp. nov. B Cladosporium maltirimosum sp. nov. C Cladosporium marinisedimentum sp. nov. D Cladosporium marinum sp. nov. E Cladosporium proteacearum F Cladosporium snafimbriatum sp. nov. " F " and " R " represent the front and the reverse sides of the culture plate, respectively. PDA: potato dextrose agar; MEA: malt extract agar; OA: oatmeal agar; SNA: synthetic nutrient-poor agar.

Figure 3. Morphological characteristics of conidial structures on SNA A Cladosporium lagenariiforme sp. nov. B Cladosporium maltirimosum sp. nov. C Cladosporium marinisedimentum sp. nov. D Cladosporium marinum sp. nov. E Cladosporium proteacearum F Cladosporium snafimbriatum sp. nov. Scale bars: 10 μm (A-F).