Phaeosphaeriopsis aloes Crous & Y. Marín, Marin-Felix et al., Stud. Mycol. 94: 61 (2019)

Index Fungorum number: IF 829642; MycoBank number: MB 829642; Facesoffungi number: FoF 09952; Fig. 1

Saprobic on dead leaves of Yucca elephantipes, visible as abundant black spots, scattered on entire leaf surface, Sexual morph Ascomata 160–220 μm high, 140–180 μm diam. (x̅=195.5×169 μm, n=10), scattered, immersed, uniloculate, globose, black, papillate, ostiolate. Peridium 10−40 μm wide, comprising two layers dark brown-walled cells of textura angularis, outer layer loosely arranged and inner layer compressed. Hamathecium of 1.5–2.5 μm wide, cellular, hyaline, septate, rarely branching, pseudoparaphyses anastomosing mostly above the asci, embedded in a mucilaginous matrix. Asci 80−100×10−12 μm (x̅=93×12 μm, n=20), 8-spored, bitunicate, fissitunicate, cylindrical, shortpedicellate, apically rounded, lacking an ocular chamber. Ascospores 16−22 × 4−5 μm (x̅=19 × 4.5 μm, n=25), overlapping biseriate, cylindrical, 3-septate at young stage, becoming 5-septate when mature, without constriction or slightly constricted at the basal septum, fourth cell swollen, hyaline when immature, becoming yellowish brown at maturity, verrucose, prominent guttules in each cell, surrounded by a thick mucilaginous sheath. Asexual morph Coelomycetous (see Marin-Felix et al. 2019a, p. 61).

Material examined – CHINA, Yunnan Province, Heilongtan, Kunming Institute of Botany, 25.137711° N 102.745185° E, on dead leaves of Yucca elephantipes (Asparagaceae), 2 February 2019, D.N. Wanasinghe, (KUNHKAS 115783, new host and new geographical record).

GenBank numbers – ITS=MZ493305; LSU=MZ493319; SSU=MZ493291; TEF1-α=MZ508414.

Notes – Phaeosphaeriopsis aloes was introduced by Marin-Felix et al. (2019a) on leaves of Aloe sp. from USA, California. In this study we have acquired DNA from a sexual morph and in multi-gene phylogeny our strain and the ex-type strain of P. aloes (CBS 145,367) group in a well-supported monophyletic clade (Fig. 2). Even though these two isolates are not derived from the same host or locality, there was only one bp difference in the comparison of the 518 nucleotides across the ITS regions. The TEF1-α gene region of CBS 145,367 is not available for further comparison. From these molecular perspectives, taxonomically, it would be wise to consider these two strains as belonging to a single species (Jeewon and Hyde 2016). The sexual morph is similar to Phaeosphaeriopsis agavensis, P. nolinae and P. obtusispora in terms of its ascospore characteristics (Câmara et al. 2003). These are however, not phylogenetically closely related (Fig. 2), therefore, we introduce our taxon as the sexual morph of Phaeosphaeriopsis aloes (Fig. 1). We could not manage to maintain a living culture as subsequent attempts to isolate failed, and hence a living culture is unavailable. Thus, we extracted DNA directly from the fruiting bodies.

Figure 1 – Phaeosphaeriopsis aloes (KUN-HKAS 115783, new host and new geographical record). a–d Ascomata observed on host substrate. e Vertical section through an ascoma. f Close of an ostiole. g Cells of peridium. h Pseudoparaphyses. j–l Asci. i, m–p Ascospores. Scale bars: d, e=50 µm, g, i–p=20 µm, h=10 µm

Figure 2 – Phylogram generated from the best scoring of the RAxML tree based on a combined SSU, LSU, TEF1-α and ITS sequence dataset to indicate the representative species in Phaeosphaeriaceae. Twenty-six strains are included in the combined analyses which comprise a total of 2930 characters. Leptosphaeria doliolum (CBS 505.75) and Paraleptosphaeria dryadis (CBS 643.86) are selected as the outgroup taxa. The best RAxML tree with a final likelihood value of − 10260.911412 is presented. RAxML analysis yielded 541 distinct alignment patterns and 25.64% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.247998, C=0.227405, G=0.266027, T=0.258570; substitution rates AC=1.142059, AG=3.643753, AT=2.176676, CG=0.693405, CT=7.632890, GT=1.00; gamma distribution shape parameter alpha=0.572735. Bootstrap support values for maximum likelihood (MLBS, left) equal to or greater than 60% are given above the nodes. Ex-type strains are in bold and newly generated sequence is in blue