Pseudopestalotiopsis indocalami Qi Yang & Yong Wang

Yang, Qi, He, Yu-Ke, Yuan, Jun & Wang, Yong, 2022, Two new Pseudopestalotiopsis species isolated from Celtis sinensis and Indocalamus tessellatus plants in southern China, Phytotaxa 543 (5), pp. 274-282 : 279-280

Pseudopestalotiopsis indocalami Qi Yang & Yong Wang bis, sp. nov. ( Fig. 3 )

MycoBank: MB 842469

Index Fungorum: IF 559462.

Etymology. indocalami , refers to the host plant ( Indocalamus tessellatus ) from which the fungus was isolated.

Type. China, Hainan Province, Wanning City , from leaves of Indocalamus tessellatus , 14 November 2020, YK He, HGUP 1072 , holotype, ex-type living culture GUCC 21600 .

Disease symptom: Associated with leaf spots of Indocalamus tessellatus . Leaf spots 12–68 mm diam., irregular to subcircular, brown, slightly sunken, scattered. Small auburn spots appeared initially and then gradually enlarge, changing to reddish-brown circular ring spots with a dark mahogany border and jagged edge.

Description: Asexual morph: Colonies on PDA reaching 6–7 cm in diam. after 7 d at room temperature (28 ˚C), under 12 hours of light-dark alternation. Mycelium light pink to light yellow, colonies filamentous to circular, slightly undulate at edge, whitish, with clustered black fruiting bodies, obviously filiform and fluffy margin, light pink from above and light yellow from reverse. Conidiomata pycnidial, 200–400 μm diam., globose, solitary, black, semiimmersed 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, or clavate, hyaline, smooth-walled. Conidia fusiform to clavate, straight to slightly curved, 4-septate, 24–31 × 4.5–6.5 (x = 27.5 × 5.4 µm), basal cell cylindrical to obconic, hyaline, thin-walled, smooth, 2.5–5.5 µm (x = 3.9 µm) long, three median cells 14–18.5 µm (x = 16.2 µm) long, concolourous, dark brown with darker septa, second cell from base 4–7 µm (x = 5.6 µm) long, third cell 3–6 µm (x = 4.4 µm) long, fourth cell 4–6.5 µm (x = 5.3 µm) long, apical cell 3.5–6.5 µm (x = 4.8 µm) long, cylindrical to sub-cylindrical, hyaline, with 2–4 (mostly 3) tubular apical appendages, arising from the apex of the apical cell each at different points, 14–28 µm (x = 19.7 µm) long, basal appendage usually present, single, tubular, unbranched, 4–6.5 µm (x = 5.1 µm) long. Sexual morph: undetermined.

Notes: Pseudopestalotiopsis indocalami (GUCC 21600) formed an independent branch in the phylogeny ( Fig. 1 ) and was related to P. curvatispora (MFLUCC 17-1722 T, MFLUCC 17-1723, MFLUCC 17-1747). Comparing the three gene regions of GUCC 21600 and P. curvatispora there was only one basepair difference in the ITS region, but five in tub2 and 15 in the tef1 region ( TABLE 2 ). Pseudopestalotiopsis curvatispora has smaller conidia than P. indocalami ((18.5–)22–25(–26.5) × (6–)6.5–7 µm), only 1–2 apical appendages and a longer basal appendage ((5.5–)9–12(–13.5) µm) ( Norphanphoun et al. 2019). Thus, P. indocalami is considered to be a novel taxon.

Figures

FIGURE 1. Maximum parsimony (MP) tree of Pseudopestalotiopsis based on combined datasets of ITS, tub2 and tef1 sequences. MP and maximum likelihood bootstrap values ≥50%, Bayesian posterior probabilities ≥0.90 (MPBS/MLBS/PPBY) are given below and above the nodes. Our strains in this study are in red. Ex-type strains are marked by T.

FIGURE 3. Pseudopestalotiopsis indocalami (GUCC 21600). a, b, c. Leaf spots on Indocalamus tessellatus. d, e. Culture on PDA (dabove, e-reverse). f. Colony sporulating on PDA. g–h. Conidia and conidiophores. i–m. Conidia. Scale bars: f = 1000 µm, g–m = 20 µm