Allophoma pterospermicola Qian Chen & L. Cai, Stud. Mycol. 94: 4 (2019)

Yuan, Jun, Zeng, Xiang-Yu, Geng, Kun, Wijayawardene, Nalin N., Bhat, Jayarama D., Wu, Shi-Ping, Wang, Yong & Yang, Zai-Fu, 2021, Allophoma species (Pleosporales: Didymellaceae) associated with Thunbergia grandiflora in Guangxi Province, China, Biodiversity Data Journal 9, pp. 63643-63643 : 63643

Allophoma pterospermicola Qian Chen & L. Cai, Stud. Mycol. 94: 4 (2019)

Materials

Type status: Other material. Occurrence: recordedBy: Jun Yuan; occurrenceID: GUCC 2070.3 and GUCC 2070.6; Taxon: scientificName: Allophoma pterospermicola; order: Pleosporales; family: Didymellaceae; genus: Allophoma; Location: country: China; stateProvince: GuangXi; locality: Nanning City, Guangxi Medicinal Botanical Garden ; verbatimCoordinates: 22°51'N, 108°19'E; Identification: identifiedBy: Jun Yuan; dateIdentified: 2020; Record Level: collectionID: HGUP 2070.3 and HGUP 2070.6

Description

Pathogenic on the leaf spot of Thunbergia grandiflora . Lesions initially on the upper leaf surface, scattered, distinct, irregular, the maximum length of the spot more than 10-13 mm, the edge of the spots yellow, the necrotic section brown at the later stage connected to form the dead leaves, on the lower leaf surface similar. Sexual morph: Undetermined. Asexual morph (Fig. 2 ): Coelomycetous. Conidiomata pycnidial, mostly aggregated and those aggregates are solitary, scattered, globose, subglobose or sometimes irregular, dark brown, glabrous, covered with some hyphal outgrowths, produced on the toothpick surface, ostiolate, (42-)52-208 × (25-)63-147 μm (x̄ = 108.1 × 99.3 μm, n = 20). Ostiole single, with a short neck, slightly papillate. Pycnidial wall pseudoparenchymatous, composed of oblong to isodiametric cells, 3-6 layers, 18-36 μm thick (x̄ = 23.6 μm, n = 10). Conidiogenous cells phialidic, hyaline, smooth, ampulliform to doliiform, 3.5-6 × 3.5-4 μm (x̄ = 3.8 × 4.3 μm, n = 10). Conidia ellipsoidal to oblong, incidentally slightly obovoid, smooth and thin-walled, hyaline, aseptate, 2.5-4 × 1.5-2.5 μm (x̄ = 3.5 × 2.5 μm, n = 20), with 2 distinct polar guttules. Conidial exudates not recorded.

Culture characteristics: Colonies on PDA, 46-50 mm diameter after 1 week, regular at margin, densely covered by floccose aerial mycelia, grey, with a white concentric ring near the margin; reverse pale black, with a white concentric ring near the margin. Colonies on MEA, 52-58 mm diameter after 1 week, regular at margin, dull green, aerial mycelia floccose, aerial mycelia sparsely, grey near the centre; reverse changing towards margin from the centre greyish-brown to brown. Colonies on OA 34-47 mm diameter after 1 week, irregular at margin, covered by floccose aerial mycelia, mycelia sparse in some furrowed zone, reverse buff to pale olivaceous.

Figures

Figure 2. Allophoma pterospermicola (GUCC 2070.3) a, b. Colony on PDA (front and reverse); c, d. Colony on MEA (front and reverse); e, f. Colony on OA (front and reverse); g. Leaf symptoms on the host; h - j. Pycnidia forming on the toothpick; k. Pycnidium; l. section of pycnidium; m. Section of pycnidial wall; n, o. Conidiogenous cells; p. Conidia. Scale bars: h, i = 500 μm; j = 100 μm; k = 50 μm; l, m = 20 μm; n-p = 5 μm.