Parathyridaria ephedrae A.J. Mattoo & S. Nonzom, 2022

Mattoo, Aroosa Jan & Nonzom, Skarma, 2022, Parathyridaria ephedrae sp. nov. (Thyridariacaeae, Pleosporales), endophytic to Ephedra gerardiana in India, Phytotaxa 556 (2), pp. 149-159 : 152-154

Parathyridaria ephedrae A.J. Mattoo & S. Nonzom , sp. nov. ( Figs 2 , 3 ).

MycoBank:—MB844240, GenBank: MW205785 (nrITS); ON598608 (nrLSU)

Etymology:— Epithet “ ephedrae ” reflects the host genus Ephedra from which the species was isolated.

Type:— INDIA. Ladakh, Kargil district: Namkila pass , isolated as an endophyte from stem of Ephedra gerardiana Wall. ex. Stapf. ( Ephedraceae ), 3700 msl elev., 34⁰20ʹ.10ʹʹN, 76⁰33ʹ.21ʹʹE, 9 September 2019, A.J Mattoo & S. Nonzom ES2 (holotype MCC 9655 ) .

Diagnosis:— Parathyridaria ephedrae differs from P. percutanea by having larger conidiomata, wart-like papillae, thicker textura angularis, and larger conidia, and from P. virginianae by having larger conidiomata and smaller conidia.

Mycelium brown, mostly entangled into stromata, hyphae septate, cells guttulate, branched, 4–13 µm wide, forming intercalary chlamydospores, 10–12 µm diameter. Conidiomata pycnidial, immersed in mycelium, erumpent, globose, subglobose to pyriform, (180–)200–320(–400) µm diameter (globose/subglobose, n = 20), (200–)300–500(–600) × (120–)200–430(–500) (pyriform, x̅ = 280 × 320 μm, n= 18), mostly scattered, few aggregated into small unresolvable groups, unilocular, papillate, papillae appear as wart-like structures, attaining hemispherical shape once detached, ostiolate. Ostioles 1–3, prominent, 65–97 × 50–79 μm (x̅ = 71 ×67 μm, n =11), with long ostiolar canal, 53–81 × 41–58 μm (x̅ = 69 ×49 μm, n=8). Conidiomatal wall (39–)49–94(–107) μm (n= 9) wide, outer 11–15 layers of dark brown cells comprised of textura angularis, lined with hyaline layers with the innermost layer bearing conidia. Conidiophores reduced to conidiogenous cells, lining the inner cavity of pycnidium. Conidiogenous cells single, densely aggregated, obclavate, hyaline to pale brown, smooth, globose, ampulliform to doliiform, with periclinal thickenings, enteroblastic, annellidic, with several precurrent proliferations frequently observed apically as well as laterally, (3.2–)4.3–7.3(–8.3) × (1.7–)2.4–4.2(–5.1) µm (x̅ = 5 × 4 µm, n =30). Conidia solitary, pale to light brown, sometimes darker at the edges, aseptate, smooth, straight or slightly curved, with 1–4 guttules, polymorphic, mostly obpyriform, clavate or ellipsoidal, few globose, cylindrical and slightly curved (1.4–)2.6–4.6(–5.5)× (1.0–)1.4–2.4(–4.7) µm (x̅ = 4.5 × 3.3 µm, n=80).

Cultural characteristics:— On PDA, surface white-grey, darker towards the periphery, later turning black, sporulating after 8–9 weeks, attaining diam. of 15–25 mm after 21 days at 25±2 ℃; reverse black. On MEA, surface smoke grey with narrow off-white periphery, flat, spreading, floccose, 15–22 mm diam. after 15 days at 25±2 ℃; reverse black with white periphery. On CDA, surface charcoal grey, 20–29 mm diam. after 15 days at 25±2 ℃, fluffy, spreading, with a small wart-like structure in the centre; reverse black with brownish-off-white periphery. On OMA, colonies floccose, centre dirty grey with broad regular, off-white periphery; reverse narrow black centre with white periphery. On WA, colonies highly restricted, 8–11 mm diam. after 15 days at 25±2 ℃, closely appressed to medium, centre mouse grey with narrow, regular, off-white periphery; reverse light to dark brown centre with white periphery.

Habitat and distribution:— Endophytic in stem of Ephedra gerardiana growing in a cold arid desert.

Notes:— Parathyridaria ephedrae forms a distinct clade basal to P. percutanea and P. ramulicola ( Fig. 1 ) and is characterized by its prominent papillae, ampulliform to doliiform conidiogenous cells, and large sized polymorphic conidia. Morphologically, the new species fits into the generic type of Parathyridaria on the basis of globose to sub-globose, papillate and ostiolate conidiomata, phialidic conidiogenous cells, and aseptate, hyaline to light brown conidia (Jaklitsch & Voglmayr 2016). Comparative account of the micromorphological characteristics between P. ephedrae and other Parathyridaria spp. with known asexual morphs is shown in Table 2 .

Figures

FIGURE 1. Phylogram inferred from maximum likelihood (ML) analysis based on a combined nrITS and nrLSU sequence dataset. Bootstrap support values (>50%) are shown above or below the branches at nodes. The newly generated strain of Parathyridaria ephedrae is shown in red. Scale bar = 0.05.

FIGURE 2. Parathyridaria ephedrae (MCC 9655, holotype). a, b. Conidiomata on nutrient medium. c. View of conidiomata showing prominent, wart-like papillae. d. Section of conidioma through papilla showing long ostiolar canal. e, f. Section through the conidiomatal wall showing multi-layered textura angularis lined with conidiogenous cells. g, h. Ampulliform and doliiform conidiogenous cells. i, j. Conidia. Scale bars a = 1000 μm, b = 500 μm, c = 200 μm, d = 50 μm, e, f = 30 μm, g–j = 10 μm. Photo credit:Aroosa Jan Mattoo.

FIGURE 3. Cultural characteristics of Parathyridaria ephedrae. a. Isolation plate showing emergence of mycelium (arrow) from a surface sterilized stem segment. b. Colonies on PDA before sporulation. c. Colony on PDA after sporulation (above, left; below, right). d–g. Colonies on MEA, CDA, OMA and WA, respectively (above, left; below, right). Photo credit: Aroosa Jan Mattoo.