Botryosphaeriales » Botryosphaeriaceae » Lasiodiplodia

Lasiodiplodia delonicis

Lasiodiplodia delonicis N. Wu, A.J. Dissanayake & Jian K. Liu, sp. nov.

Index Fungorum number: IF900581; Facesoffungi number: FoF14261.

Etymology: Referring to the host genus on which the fungus was collected, Delonix regia (Fabaceae).

Holotype: MFLU 23-0005.

Saprobic on a fallen pod of Delonix regia L. Sexual morph: Not observed. Asexual morph: Conidiomata 110–180 × 124–171 μm (x̅ = 139 × 151 μm, n = 20), pyriform, immersed to semi-immersed, solitary, black, ostiolate. Ostiole 20–31 μm diam., central, cylindrical to subcylindrical. Peridium up to 18–35 μm wide, with outer 3–4 layers of brown cells of textura angularis and inner 1–2 layers of hyaline cells of textura angularis. Paraphyses 2–3 μm wide, hyaline, cylindrical, aseptate, not branched. Conidiophores are reduced to conidiogenous cells. Conidiogenous cells 4–16 × 4–6 μm (x̅ = 8 × 5 μm, n = 20), hyaline, cylindrical, sometimes slightly curved. Conidia 26–38 × 13–29 μm (x̅ = 32 × 17 μm, n = 50), ellipsoid to ovoid, hyaline, aseptate, thick-walled with granular content, occasionally truncate at base, without longitudinal striations or mucilaginous sheath.

Culture characteristics: Conidia germinating on PDA within 24 h. Colonies are fast growing on PDA, reaching 90 mm diam. after 5 days at 20–25 °C, becoming ash-grey on the surface after one week, with the reverse side of the colonies pale grey to grey, and finally black after two weeks, felt-like, sparse, aerial, surface smooth with crenate edge, filamentous.

Material examined: Thailand, Chiang Rai Province, Amphoe Mueang, Tambon Nang Lae, 20°02’22.7’’ N, 99°53’38.1’’ E, on a fallen pod of Delonix regia, 17 July 2019, Na Wu, YW111 (MFLU 23-0005, holotype); ex-type living culture MFLUCC 23-0058.

Notes: The phylogenetic tree based on ITS, LSU, tef1-α, and tub2 sequence data showed that the new species Lasiodiplodia delonicis (Figure 1) is supported by an absolute bootstrap support (ML/MP/BI = 100/100/1.0). Morphologically, L. delonicis is distinct from other Lasiodiplodia species by its thicker conidial wall and larger conidia. Additionally, conidia of L. delonicis are hyaline throughout the life cycle.