Paraboeremia truiniorum Hern.-Restr., L. W. Hou, L. Cai & Crous, 2020

Hou, Lingwei, Hernandez-Restrepo, Margarita, Groenewald, Johannes Zacharias, Cai, Lei & Crous, Pedro W., 2020, Citizen science project reveals high diversity in Didymellaceae (Pleosporales, Dothideomycetes), MycoKeys 65, pp. 49-99 : 49

Paraboeremia truiniorum Hern.-Restr., L. W. Hou, L. Cai & Crous sp. nov. Figure 8

Etymology.

truiniorum refers to Cuno & Tygo Truin who collected the soil sample from which the ex-type strain was isolated.

Typus.

The Netherlands. Gelderland province, Barneveld, Voorthuizen, isolated from garden soil, Mar. 2017, C. Truin & T. Truin (holotype designated here CBS H-24108, living ex-type culture CBS 144952 = JW 47002).

Conidiomata pycnidial, superficial, scattered or aggregated, most solitary, globose or subglobose, confluent and irregularly-shaped with age, pale brown, thick-walled, covered with abundant mycelial outgrowths, 160-420 × 135-430 μm; 1-papillate or non-papillate ostioles, sometimes elongated to a short neck; pycnidial wall pseudoparenchymatous, 7-11 layers, 40-70 μm thick, outer layers composed of brown, flattened polygonal cells of 22-45.5 μm diam. Conidiogenous cells phialidic, hyaline, smooth, globose, subglobose, ampulliform or doliiform, 4.5-8.5 × 4-7 μm. Conidia ellipsoidal to oblong, thin- and smooth-walled, hyaline, aseptate, 3.5-5 × 2-3 μm, with (1-)2 large guttules. Conidial matrix whitish.

Culture characteristics.

Colonies after 7 d at 25 °C, on OA reaching 70-75 mm diam, aerial mycelium floccose, vinaceous buff to hazel, margin regular; reverse buff to olivaceous. On MEA reaching 65-70 mm diam, aerial mycelium felty, whitish, pale mouse grey toward periphery, margin regular; reverse dark brick to dark brown, with pale brown edge. On PDA reaching 75-80 mm diam, aerial mycelium felty, olivaceous buff to pale mouse grey, olivaceous toward periphery, margin irregular; reverse mouse grey, olivaceous toward periphery. NaOH spot test negative on OA.

Additional specimens examined.

The Netherlands, Gelderland province, Culemborg, isolated from garden soil, Mar. 2017, R. Fuld, JW 182014; The Netherlands. South Holland province, Alphen aan den Rijn, isolated from garden soil, Mar. 2017, K. Boutwell, CBS 144961 = JW 203021; The Netherlands. South Holland province, Gorinchem, isolated from garden soil, Mar. 2017, L. van Rosmalen, JW 270002; The Netherlands. Utrecht province, Utrecht, isolated from garden soil, Mar. 2017, L. van Rijnberk, JW 147025; The Netherlands. Utrecht province, Woerden, isolated from garden soil, Mar. 2017, L. Borsboom, JW 192003.

Notes.

Based on the phylogenetic analyses, P. truiniorum is represented by six isolates, forming a distinct lineage (Figure 1 ). Paraboeremia truiniorum is characterised by the dense mycelial outgrowths on its pycnidia. Both P. truiniorum and P. rekkeri are phylogenetically close to the well-known soil-borne species, P. putaminum . However, P. putaminum is distinguished from these two new species by producing smaller conidia (3.2-4.2 × 2-2.6 μm) with greenish guttules ( Boerema et al 2004).

Figures

Figure 1. Phylogenetic tree generated from the maximum-likelihood analysis based on the combined ITS, LSU, tub 2 and rpb 2 sequence alignment of Didymellaceae members. The RAxML bootstrap support values (BS), Bayesian posterior probabilities (PP), and parsimony bootstrap support values (PBS) are given at the nodes (BS / PP / PBS). BS and PBS values represent parsimony bootstrap support values> 50 %. Full supported branches are indicated in bold. The scale bar represents the expected number of changes per site. Ex-type strains are represented in bold. Strains obtained in the current study are printed in green; among them, whilst strains that represent new taxa are printed in red. Some of the basal branches were shortened to facilitate layout (the fraction in round parentheses refers to the presented length compared to the actual length of the branch). The tree was rooted to Coniothyrium palmarum CBS 400.71 and Leptosphaeria doliolum CBS 505.75.

Figure 8. Paraboeremia truiniorum (CBS 144952). A, B Colony on OA (front and reverse) C, D colony on MEA (front and reverse) E, F colony on PDA (front and reverse) G pycnidia forming on OA H pycnidium I section of pycnidium J section of pycnidial wall K-N conidiogenous cells O conidia. Scale bars: 20 μm (H); 50 μm (I); 5 μm (J-O).