Pleosporales » Lentitheciaceae » Phragmocamarosporium

Phragmocamarosporium hederae

Phragmocamarosporium hederae Wijayaw., R.K. Schumach. & K.D. Hyde. Index Fungorum 370: 1 (2018)

 

Associated with leaf spots on Cycas (Cycadaceae). Sexual morph: Undetermined. Asexual morph: Conidiomata 130–170 μm high, 180–270 μm diam., pycnidial, semi-immersed, visible as raised, black dots on host surface, scattered, solitary to gregarious, globose to subglobose, glabrous, uni-loculate, ostiolate at centre, with minute papilla, lacking periphyses. Conidiomata walls 10–20 μm, thin-walled, of equal thickness, composed of 3–5 layers, of flattened, brown to dark brown, pseudoparenchymatous cells, with blackened cells at the papilla, arranged in textura angularis to textura prismatica, difficult to distinguish from conidiogenous cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells (2.5–)3–5(–8) × (1.5–)2–5(–7) µm (x̄ = 4.3 × 3.7 μm, n = 30), holoblastic, phialidic, hyaline, smooth, aseptate, ampulliform, arising from the inner cavity of the conidioma wall. Conidia (8–)10–13(–14) × 3–4 µm (x̄ = 12 × 4.2 μm, n = 50), initially light brown, becoming reddish-brown to brown, oblong to ellipsoidal, or subclavate with truncate base, 3-septate, not constricted at the septa, smooth-walled.

 

Culture characteristics: Colonies on PDA reaching 10–15 mm diam. after 10 days at 25–30 °C; from above, white to cream at the margin, grey at the centre; from below, white to cream at the margin, black at the centre; medium dense, circular, slightly raised, surface slightly smooth, with edge entire, fluffy to feathery; not producing pigmentation in agar.

 

Habitat:  leaf spots on Cycas 

 

Known distribution: China

 

Material examined: CHINA, Yunnan Province, Kunming City, Kunming Institute of Botany, associated with leaf spots on Cycas (Cycadaceae), 5 April 2017, R. Phookamsak, KIB020 (KUN-HKAS 102237), living culture, KUMCC 18-0165 (KIB020A), MFLUCC 18-0677 = KUMCC 18-0166 (KIB020B).

 

GenBank numbers: ITS = MK214369, LSU = MK214372, SSU = MK214375, TEF1-α = MK214378 (KUMCC 18-0165); ITS = MK359434, LSU = MK359439, SSU = MK359444, TEF1-α = MK359073 (KUMCC 18-0166).

 

Notes: A BLASTn search of LSU and SSU sequence data indicates that MFLUCC 18-0677 is identical to P. hederae (100% and 99% similarities, respectively). We therefore, identify our isolate as P. hederae and this species was collected from Cycas in China for the first time. Our new isolate is similar to P. hederae in having phragmosporous conidia. Whearas, P. platani has phragmosporous and muriform conidia at maturity (Wijayawardene et al. Compared to the type of P. hederae our new isolate has shorter and broader conidiogenous cells (8–10 × 1.5–2.5 μm in the type collection) and longer conidia (9–11 × 3–4.5 µm in the type collection). Phragmocamarosporium platani has smaller conidiogenous cells (1.5–3 × 1.5–2.5 μm) and narrower conidia (12–13 × 5–7.5 μm) (Wijayawardene et al. Only LSU and SSU sequence data for P. hederae and P. platani are available in GenBank, and sequences of more informative genes are needed to clarify species in this genus.