Paraboeremia rekkeri 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 rekkeri Hern.-Restr., L. W. Hou, L. Cai & Crous sp. nov. Figure 7

Etymology.

rekkeri refers to Daan Rekker who collected the soil sample from which the ex-type strain was isolated.

Typus.

The Netherlands. Gelderland province, Geldermalsen, isolated from garden soil, Mar. 2017, D. Rekker (holotype designated here CBS H-24107, living ex-type culture CBS 144955 = JW 172002).

Conidiomata pycnidial, superficial, scattered or aggregated, solitary or confluent, globose or subglobose, irregularly-shaped with age, buff to brown, covered with abundant mycelial outgrowths especially when young, 150-390 × 120-320 μm; 1-2 papillate or non-papillate ostioles; pycnidial wall pseudoparenchymatous, 3-7 layers, 17.5-37 μm thick, outer layers composed of brown, flattened polygonal cells, 10-21 μm diam. Conidiogenous cells phialidic, hyaline, smooth, globose, subglobose or ampulliform, 5-10 × 4.5-7.5 μm. Conidia ellipsoidal to oblong, thin- and smooth-walled, hyaline, aseptate, 3.5-5 × 2.5-3 μm, with 2(-3) large guttules. Conidial matrix pink.

Culture characteristics.

Colonies after 7 d at 25 °C, on OA reaching 75-80 mm diam, aerial mycelium floccose, saffron, vinaceous buff, pale olivaceous, margin regular; reverse concentric circles saffron, grey, olivaceous grey. On MEA reaching 55-60 mm diam, aerial mycelium floccose, margin irregular, pale olivaceous grey to whitish, orange near edge; reverse brown to dark brown, orange towards the periphery. On PDA reaching 70-75 mm diam, margin irregular, covered by felty aerial mycelium, buff, olivaceous grey towards periphery; reverse mouse, olivaceous towards periphery. NaOH spot test negative on OA.

Additional specimens examined.

Gelderland province, Culemborg, isolated from garden soil, Mar. 2017, H. van de Warenburg, JW 3018; Kapel-Avezaath, isolated from garden soil, Mar. 2017, A. Panneman, JW 79024; Meteren, isolated from garden soil, S. van Stuijvenberg, JW 132004; North Brabant province, Breda, isolated from garden soil, Mar. 2017, F. Wiegerinck, CBS 144949 = JW 4024; Breda, isolated from garden soil, Mar. 2017, F. Versantvoort, JW 167006; Zwanenburg, isolated from garden soil, Mar. 2017, J. Rebergen, JW 91008; North Holland province, Alkmaar, Mar. 2017, B. Verschoor, JW 13016, ibid. JW 13017 and JW13030; Utrecht province, Bilthoven, isolated from garden soil, Mar. 2017, H. Vos & S. Vos, JW 51014; Eemnes, isolated from garden soil, Mar. 2017, H.W. Vos, CBS 144950 = JW 6005; Hooglanderveen, isolated from garden soil, Mar. 2017, F. Rijpma, JW 25013; Utrecht, isolated from garden soil, R. van Zijl, JW 226002.

Notes.

Paraboeremia rekkeri formed a well-supported (1.0/100/96) distinct lineage in Paraboeremia (Figure 1 ). It is most closely related with P. truiniorum , another novel species collected from Dutch soil and described in the present study. However, P. rekkeri is distinguished by producing larger pycnidia (150-390 × 120-320 μm), with a thinner pycnidial wall (3-7 layers and 17.5-37 μm thick). Pycnidia in P. truiniorum are 160-420 × 135-430 μm, and have a wall of 7-11 layers and 40-70 μm thick.

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 7. Paraboeremia rekkeri (CBS 144955). 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: 100 μm (H); 20 μm (I); 10 μm (J); 5 μm (K-O).