Neopestalotiopsis rhododendri Qi Yang & Yong Wang bis, Biodiversity Data Journal 9(no. e70446): 9 (2021) Fig. 10

 Index Fungorum number: IF 840066; MycoBank number: MB 840066; Facesoffungi number: FoF 12918;

Associated with leaf spots of Rhododendron simsii. The leaf spots are small irregular to subcircular shape, brown, slightly sunken spots appear on surface leaves of R. simsii, which scattered on the surface leaves tip and eventually develops into a large lesion. Small off-white spots appeared initially and then gradually enlarged, changing to light brown circular ring spots with a dark brown border. Sexual morph: undetermined. Asexual morph: Conidiomata 55–280 μm in diam., pycnidial, globose, solitary, black, semi-immersed on PDA, exuding brown to dark brown mass of conidia. Conidiophores often reduced to conidiogenous cell, regularly septate and branched at the base. Conidiogenous cells mostly integrated, ampulliform, cylindrical, hyaline to light brown, smooth-walled. Conidia (25.5–)30 × 5(–6) μm (x̄ = 27.6 × 5.5 μm, n = 30), fusiform to clavate, straight to slightly curved, 4-septate; basal cell obconic, hyaline, thin-walled, smooth, 3.5–6.5 μm (x̄ = 4.5 μm, n = 30); the three median cells 13.5–19.5 μm (x̄ = 16.3 μm, n = 30), light brown to dark brown, dark brown with septa darker than the rest of the cells, the second cell from base 4–6 μm (x̄ = 5 μm, n = 30); the third cell 3.5–5.5 μm (x̄ = 4.5 μm, n = 30); the fourth cell 4–6.5 μm (x̄ = 4.8 μm, n = 30); apical cell 3.5–6.3 μm (x̄ = 5 μm, n = 30), cylindrical to sub-cylindrical, hyaline, 1–3 (mostly 2) tubular apical appendages, arising from the apex of the apical cell each at different points, 21–38.5 μm (x̄ = 29.2 μm, n = 30); basal appendage present most of the time, single, tubular, unbranched, 6–11.5 μm (x̄ = 8.5 μm, n = 30).

Culture characteristics – Colonies on PDA reaching 6.5–7 cm in diam. after 7 d at room temperature (28 °C), under light 12 hr/dark. Hyphae white, colonies filamentous to circular, slightly undulate at the edge, with black fruiting bodies clustered, has filiform and fluffy margin, white from above and light yellow from the reverse.

Material examined – China, Yunnan Province, Kunming City, from leaves of Rhododendron simsii, 12 February 2018, Q. Zhang, HGUP 134, holotype, ex-type living culture GUCC 21-504. ibid., Guizhou Province, Kaili, from leaves of Rhododendron simsii, Qi Yang, HGUP 997, GUCC 21-505.

Notes – In the multi-gene analysis, strain GUCC 21-504 formed a distinct clade with a sister strain GUCC 21-505, but the node support values were 68/90/- (MP/ML/BI) and these two strains were close to N. protearum (CBS 114178). When comparing the polymorphic nucleotide differences of our two strains, there are 18 base pair differences, seven in ITS, two in tub2 and nine in tef1, but without obvious distinction (higher than 98.5%). Compared with N. protearum and our ex-type strain (GUCC 21-504), there were six character differences with N. protearum in the ITS region, three character differences with N. protearum in the tub2 region, but 12 character differences from N. protearum in the tef1 region; thus the DNA base pair differences were mainly inthe tef1 gene regions. The morphological differences between our strains and N. protearum were wider conidia (N. protearum: 24.8 ± 1.5 × 8.5 ± 0.6 μm), more apical appendages (N. protearum: 3–5) and shorter basal appendages (N. protearum: 5–8μm) (Maharachchikumbura et al. 2014). Thus, Neopestalotiopsis rhododendri isintroduced as a novel taxon, based on morphology and phylogeny.

Figure 1 – Neopestalotiopsis rhododendri (GUCC 21504). a, b, c. Leaf spots of Neopestalotiopsis rhododendri; d, e. Culture on PDA (d-above, e-reverse); f. Colony sporulating on PDA; g–h.Conidia and conidiophores; i–m. Conidia. Scale bars: f = 1000 μm, g–m = 20 μm