Neoroussoella entadae Jayasiri, E. B. G. Jones & K. D. Hyde

Htet, Zin Hnin, Hyde, Kevin D., Alotibi, Fatimah O., Chethana, Thilini K. W. & Mapook, Ausana, 2024, Multigene phylogeny, taxonomy, and potential biological properties of Pseudoroussoella and Neoroussoella species (Roussoellaceae, Dothideomycetes) from Asteraceae weeds in northern Thailand, MycoKeys 111, pp. 129-146 : 129-146

Neoroussoella entadae Jayasiri, E. B. G. Jones & K. D. Hyde , Mycosphere 10 (1): 105 (2019)

Fig. 3

Description.

Saprobic on the dead stems of Chromolaena odorata ( Asteraceae ). Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata 70–120 × 100–150 µm (av. 95 × 110 µm, n = 5), pycnidial, solitary, globose to subglobose, uniloculate, immersed to semi-immersed, ostiolate. Ostiole 30–35 µm wide, with small papillate. Peridium 10–20 µm wide, comprising 2–3 layers of brown cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 3–5 × 1–3 µm (av. 3.8 × 2.1 µm, n = 10), phialidic, ampulliform to cylindrical, hyaline. Conidia 3–5 × 2–4 μm (av. 3.8 × 2 μm, n = 20), hyaline, becoming pale brown when gathering, oblong to ovoid, aseptate, with small guttules.

Culture characteristics.

Conidia germinating on PDA within 24 hours, reaching 24 mm after 7 days at 27 ° C, irregular, entire, yellowish-brown, slightly wrinkled on the surface; pale brown to brown in reverse.

Material examined.

Thailand • Chiang Rai Province, Thoeng district , on dead stems of Chromolaena odorata ( Asteraceae ), 24 Jan 2022, A. Mapook (TCR 18, MFLU 24-0265 , new host record); living culture MFLUCC 24-0275 .

Known host distribution.

Entada phaseoloides ( Fabaceae ), Leucaena sp. ( Fabaceae ) ( Jayasiri et al. 2019).

Notes.

In a BLASTn search of GenBank, the closest match for the ITS sequence of our isolate was N. solani strain MnF 107 (OQ 704272) with 99.83 % similarity. The closest match for the LSU region was Roussoella sp. strain HF 3 S 53 ( OP 179275 ) with 99.77 % similarity, and the closest match for the SSU region was Pleosporales sp. IRB 20-2 (AB 195632) with 100 % similarity. The closest match for the tef 1 - α and rpb 2 gene region was Neoroussoella entadae strain MFLUCC 18-0243 ( MK 434866 ) with 99.78 % and 99.53 % similarity, respectively.

When we compared the morphology, our isolate is similar to N. entadae ( MFLUCC 17–0920 ) in having solitary, unilocular, ostiolate conidiomata, phialidic, ampulliform to cylindrical, hyaline conidiogenous cells, and oblong to ovoid, hyaline conidia with size (3–5 × 2–4 μm vs 3–4 × 1.7–1.9 μm). However, our isolate differs from N. entadae ( MFLUCC 17–0920 ) in having smaller conidiomata (70–120 × 100–150 µm vs. 127–192 × 161–190 µm), slightly wider conidiogenous cells (3–5 × 1–3 µm vs. 3.5–5.6 × 0.7–1.8 µm) (Table 3 ).

Based on the multi-locus phylogeny (Fig. 1 ), our isolate MFLUCC 24-0275 clustered in the same clade with N. entadae ( MFLUCC 18-0243 ). Moreover, there is no significant base pair difference between MFLUCC 24-0275 and N. entadae ( MFLUCC 18-0243 ). Therefore, we reported N. entadae as the first occurrence on C. odorata ( Asteraceae ) based on morphology and multigene phylogeny.

Figures

Figure 1. Phylogram generated from maximum likelihood analysis based on the combined dataset of LSU, SSU, ITS, tef 1 - α and rpb 2 sequence data. Bootstrap support values for ML equal to or greater than 75 % and BYPP equal to or greater than 0.90 are given at the nodes. Newly generated sequences are in blue and type species are in bold.

Figure 3. Neoroussoella entadae (MFLU 24-0265, new host record) a, b Conidiomata on the substrate c a section through conidioma d ostiole e peridium f conidia and conidiogenous cells g – i conidia j a germinating conidium k culture on the MEA. Scale bars: 500 µm (a); 200 µm (b); 50 µm (c); 20 µm (d, e); 5 µm (f, g, h, i, j).