Sarocladium gamsii A. Giraldo, Gené & Guarro

Asghari, Raheleh, Phukhamsakda, Chayanard, Jones, E. B. Gareth, Bahkali, Ali, Apurillo, Carlo Chris S., Karimi, Omid, Kakumyan, Pattana & Hyde, Kevin D., 2025, Morphology and phylogeny reveal two new species and host records of hyphomycetous fungi on Areca species from marine habitats in Thailand, MycoKeys 118, pp. 179-206 : 179-206

Sarocladium gamsii A. Giraldo, Gené & Guarro

Description.

Saprobic on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig. 9 ). Colonies on natural substrates hairy, effuse, scattered, grayish, shiny, with black conidiophores. Synemata, tree-like, 240–280 µm height (x – = 328 μm, n = 10), wider at the base 25–62 µm wide (x – = 44 μm, n = 10), narrower in the middle 17–30 µm wide (x – = 24 μm, n = 10), divergent in the upper part, composed of 8–20 conidiophores at the base of each stipe. Conidiophores 193–298 × 1.5–3 µm (x – = 259 × 2.5 μm, n = 15), solitary or in groups, macronematous, synnematous, twisted in the stipe, parallel in the upper part, irregularly branched, straight or slightly flexuous, septate, smooth, brown, subhyaline to hyaline at the upper part. Conidiogenous cells 10–39 × 1.5–2.5 µm (x – = 21 × 2 μm, n = 15), polyphialidic, integrated or terminal, cylindrical, straight to slightly curved or sympodial at the upper part, acropetally proliferating, subhyaline to hyaline, finely aculeate, denticle at the attachment site of conidia, without collarette. Conidia 2-6.5 × 1.5-2.5 µm (x – = 4 × 2 μm, n = 30), unicellular, fusiform, truncate at base, rounded apex, hyaline, thick-walled, smooth-walled, guttulate, bud scars or disjunctors present at the site of attachment. Hyphomycetous (in vitro, Fig. 10 ). Colonies on PDA. Vegetative hyphae hyaline, smooth-walled, thin-walled, septate. Conidiophores 8.5–47 (– 76) µm (x – = 29 μm, n = 15) height, arising from vegetative hyphae or ropes of hyphae, straight, flexuous or slightly bent, slightly tapering toward the apex, unbranched to rarely branched, smooth-walled to asperulate, hyaline, aseptate or uniseptate at the base. Conidiogenous cells 5.5–45 × 1–1.75 µm (x – = 27 × 1.3 μm, n = 15), monophialidic, acicular, with apical periclinal thickening, finely asperulate, hyaline. Conidia 3-5 × 1-2 µm (x – = 4.5 × 1.5 μm, n = 30), solitary or forming in slimy heads or chains, hyaline, unicellular, fusiform, thick-walled, guttulate, finely asperulate. Chlamydospores not observed.

Culture characteristics.

Conidia germinating on PDA within 12 h. Colonies on PDA reaching 2.5 cm diam. after one month and 3 cm diam. after two months at 25 ± 2 ° C, umbonate, radially folded, lobate to irregular, yellowish white. Reverse buff.

Material examined.

Thailand, Prachuap Khiri Khan Province, Pranburi , on decaying Areca wood submerged in seawater and trapped between rocks, 25 October 2022, K. D. Hyde, R 6 d ( MFLU 24-0451 ), living culture ( MFLUCC 24-0561 ) .

GenBank numbers.

Sarocladium gamsii MFLUCC 24-0561 : ITS = PQ 778937, LSU = PQ 778932.

Notes.

The reconstruction of phylogenies from combined LSU, ITS and act sequences showed that Sarocladium gamsii ( MFLUCC 24-0561 ) formed a sister clade with S. gamsii ( CBS 707.73 in both maximum likelihood and Bayesian analyses with 100 % ML / 1 BPP statistical support (Fig. 4 ). In a BLAST search in GenBank, the closest match of the ITS sequence of S. gamsii ( MFLUCC 24-0561 ) was 99 % similar across 95 % of the query sequence to S. gamsii ( PUPYF 263 _ ANAMORPH). In a BLAST search in GenBank, the closest match of the LSU sequence of Sarocladium gamsii ( MFLUCC 24-0561 ) was 99 % similar across 100 % of the query sequence to Monocillium sp. ( CBS 187.80 ). Sarocladium gamsii ( MFLUCC 24-0561 ) has similar morphology to S. gamsii ( CBS 707.73 ) in having straight or slightly bent, unbranched or rarely branched conidiophores arising from vegetative hyphae or ropes of hyphae, monophialidic conidiogenous cells with apical periclinal thickening, fusiform, hyaline, aseptate conidia forming in chains or slimy heads, but it differs in having finely asperulate conidiogenous cells and conidia ( Giraldo et al. 2015). Sarocladium gamsii ( MFLUCC 24-0561 ) is introduced as a new host record based on morphology and phylogenetic evidence.

Figures

Figure 4. Phylogram generated from maximum likelihood analysis based on combined LSU, ITS and act sequence data of Sarocladium. Maximum likelihood bootstrap support ≥ 65 % and Bayesian posterior probabilities (BPP) ≥ 0.90 are given near the nodes, respectively. The tree is rooted to Kiflimonium curvulum (CBS 430.66, CBS 384.70 A). The newly generated sequence is highlighted in yellow, and the type strains are indicated in bold.

Figure 9. Sarocladium gamsii (MFLU 24-0451, a new host record) a colonies on substrate b close-up of colonies on substrate c synnemata d base of synnemata e apex of synemata f, g conidiogenous cells and conidia h conidiogenous cell and conidia, indicating denticles at the attachment site of conidia i conidia j colony on PDA after one month (above and below). Scale bars: 100 µm (b, c); 20 µm (d, e); 10 µm (f, g); 5 µm (h, i).

Figure 10. Sarocladium gamsii (MFLUCC 24-0561, a new host record) a, b colonies on PDA after two months c – e conidiophores and conidia f conidia arranged in chains g conidia arranged in slimy heads h, i conidia. Scale bars: 20 µm (c – e); 5 µm (h, i).