Remispora submersa

Calabon, Mark S., Jones, E. B. Gareth, Pang, Ka-Lai, Abdel-Wahab, Mohamed A., Jin, Jing, Devadatha, Bandarupalli, Sadaba, Resurreccion B., Apurillo, Carlo Chris & Hyde, Kevin D., 2023, Updates on the classification and numbers of marine fungi, Botanica Marina (Warsaw, Poland) 66 (4), pp. 213-238 : 228

2.5.19 Remispora submersa

This new species was described based on the close phylogenetic relationship with Remispora quadri-remis and R. stellata in a phylogenetic tree of 28S and ITS rDNA ( Gonçalves et al. 2021). This is an asexual fungus producing white mycelia and abundant cylindrical conidia. The conidiogenesis was unclear although it was described as “ conidiophores reduced to conidiogenous cells ”. This type of asexual morphology is unusual in the Halosphaeriaceae , as they generally have brown, septate conidia. A wider range of taxa should have been included in the phylogenetic analysis, especially the type species of Remispora , R. maritima . Holotype material was requested, especially slides of the conidiophores and conidia, but these were not available. A culture of R. submersa was provided, but failed to sporulate, despite growth on three different media and wood picks ( Figure 5 ). The culture was re-sequenced, grouping in the Sarocladium clade and the species S. kiliense with high statistical support ( Figure 6 ), a species with hyaline conidia as in those reported for R. submersa . Further studies are required to resolve this anomaly.

Figures

Figure 5: Colony of Remispora submersa (MUM 20.48) in malt extract agar (MEA) for 7 days at 25 °C: (A) obverse, (B) reverse.

Figure 6: Phylogram generated from maximum likelihood (ML) analysis based on combined LSU, ITS, and act1 sequence data representing Sarocladiaceae (Hypocreales). Thirty-seven strains are included in the combined analyses which comprised 1753 characters (504 characters for LSU, 478 characters for ITS,771 characters for act1) after alignment. Acremonium variecolor strains CBS 130360 and FMR 11141 in Bionectriaceae (Hypocreales) were used as the outgroup taxa. The best scoring RAxML tree with a final likelihood value of −8526.836 is presented. The matrix had 435 distinct alignment patterns, 356 parsimony-informative, 73 singleton sites, and 1332 constant sites. Estimated base frequencies were as follows: A = 0.216, C = 0.298, G = 0.265, T = 0.221; substitution rates: AC = 2.09479, AG = 3.08268, AT = 2.09479, CG = 1.00000, CT = 10.05849, GT = 1.000000; gamma distribution shape parameter α = 0.574. Bootstrap support values for ML equal to or greater than 75 % are given above the nodes (left side). Bayesian posterior probabilities (BYPP) equal to or greater than 0.95 are given above the nodes (right side). Ex-type strains are in bold and newly generated sequences are in blue.