Rosellinia maritima R. Asghari, Phukhams. & K. D. Hyde, 2025

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

Rosellinia maritima R. Asghari, Phukhams. & K. D. Hyde sp. nov.

Etymology.

The epithet “ maritima ” refers to the marine habitat where the holotype was collected.

Holotype.

MFLU 24-0452 .

Description.

Saprobic on decaying branches of Areca sp. Sexual morph: Undetermined. Asexual morph: Hyphomycetous (in vivo, Fig. 6 a – e ). Colonies on natural substrates superficial, effuse, scattered, black. Mycelia on natural substrates superficial to immersed, branched, septate, subhyaline to brown. Sterile globules 52-74 × 47-69 µm (x – = 62 × 56 μm, n = 20), conidial-like, produced laterally or terminally on the hyphae, solitary, globose to subglobose or irregular, muriform appearance, composed of interwoven, unevenly arranged cells with irregular shapes, thick-walled, dark brown to black, darker in the center. Hyphomycetous (in vitro, Fig. 6 f – x ). Colonies on PDA. Vegetative hyphae subhyaline, pale brown to brown, branched, septate, simple or sometimes irregularly moniliform. Conidiophores not seen or micronematous. Conidiogenous cells integrated, up to 13 μm in length, subcylindrical, subhyaline to brown. Conidia 8-13 × 5-10 µm (x – = 10.5 × 7.5 μm, n = 15), aleurioconidia, solitary, obovoid, truncate base, hyaline to brown, thick-walled, guttulate, intercalary, laterally or terminally, initiating by hyphal inflammation and separating from hyphae by forming septa. Sterile globules 37-145 × 31-66 µm (x – = 79 × 49 μm, n = 20), conidial-like, produced laterally or terminally on the hyphae, solitary, globose to subglobose, oblong or irregular, muriform appearance, agglomerations of hyphal structures, composed of interwoven, unevenly arranged cells with irregular shapes, thick wall, dark brown to black, darker in the center.

Culture characteristics.

Conidia germinating on PDA within 12 h. Colonies on PDA reaching 5 cm diam. after one month at 25 ± 2 ° C, felty, flat, round, entire margin, dull, gray and white concentric rings, with dirty whitish edge, reverse dark brown with olivaceous gray edge.

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 c ( MFLU 24-0452 , holotype), isotype ( MFLU 24-0453 ), ex-type living culture ( MFLUCC 24-0562 ), ex-isotype living culture ( MFLUCC 24-0564 ) .

GenBank numbers.

Rosellinia maritima MFLUCC 24-0562 (ex-type): ITS = PQ 778938, LSU = PQ 778933, tub 2 = PQ 885479, rpb 2 = PQ 885483; Rosellinia maritima MFLUCC 24-0564 (ex-isotype): ITS = PQ 778939.

Notes.

The construction of phylogenies from combined ITS, LSU, tub 2 and rpb 2 sequence data showed that Rosellinia maritima ( MFLUCC 24-0562 ) formed a subclade to a group of Rosellinia species: R. sanctae-cruciana ( HAST 90072903 ), R. nectrioides ( CBS 449.89 ), R. abscondita ( CBS 447.89 ), R. marcucciana ( MUCL 51704 ), R. mammiformis ( CBS 445.89 ) and R. britannica ( MFLU 17-0987 , HKAS 102349 ) in both maximum likelihood and Bayesian analyses with 85 % ML / 0.95 BPP statistical support showing the same topology. In a BLAST search in GenBank, the closest match of the ITS sequence of R. maritima ( MFLUCC 24-0562 ) was 95 % similar across 66 % of the query sequence to Rosellinia sp. isolate ( OTU 1178 ), which was obtained using Illumina sequencing, and its morphology is not available ( Gao et al. 2020). In a BLAST search in GenBank, the closest match of the LSU sequence of R. maritima ( MFLUCC 24-0562 ) was 98.48 % similar across 94 % of the query sequence to R. sanctae-cruciana strain BB. Rosellinia maritima ( MFLU 24-0452 ) is not comparable with Rosellinia sanctae-cruciana as the morphology of its asexual morph is not available. Asexual morphs of Rosellinia have been recorded to be geniculosporium-like, dematophora-like, or nodulisporium-like ( Petrini 2013), which is different from R. maritima ( MFLU 24-0452 ) in having distinguished conidiophores, monoblastic geniculate conidiogenous cells, and ellipsoidal conidia. Rosellinia maritima ( MFLUCC 24-0562 ) has morphological similarities with R. truncatispora in culture, producing pale brown, thick-walled, septate hyphal sterile elements. However, it differs by having sterile globules and aleurioconidia in culture ( Fournier et al. 2017). Therefore, we introduced our collection of R. maritima ( MFLU 24-0452 ) as a novel species based on its distinct morphology and phylogenetic evidence.

Figures

Figure 6. Rosellinia maritima (MFLU 24-0452, holotype) a colonies on substrate b close-up of colonies on substrate c – e sterile globules (conidial-like elements) f – x Rosellinia maritima (MFLUCC 24-0562, ex-type) f, g colony on PDA (above and reverse) h, i close-up of colonies in culture j sterile globules in culture k, l mycelia m – o developing aleurioconidia p aleurioconidia q – t developing sterile hyphal elements u – x developing sterile globules. Scale bars: 500 µm (b); 250 (h); 100 (i); 50 (j); 20 µm (c – e, k – l, w, x); 10 µm (m – v).