Oidiodendron boninense D. Hirose, 2022

Hirose, Dai, Tokiwa, Toshiyuki & Yaguchi, Takashi, 2022, Two novel Oidiodendron species isolated from roots of Vaccinium boninense in the Bonin Islands, Japan, Phytotaxa 566 (1), pp. 89-104 : 97-99

Oidiodendron boninense D. Hirose sp. nov. ( Fig. 2–3 )

MycoBank number: MB844530

Description:

Sexual morphs not observed. Colony diam., 28 days, in mm (minimum–maximum): CMA: 5 ˚C (1–1.5), 10 ˚C (1–2), 15 ˚C (4–11), 20 ˚C (13–20), 25 ˚C (20–25), 30 ˚C (13–22), and 35 ˚C (no growth); PDA: 25 ˚C (18–31); OA: 25 ˚C (23–30); MEA: 25 ˚C (15–36). Colonies on CMA at 25 ˚C, good sporulate, velvety, hazel (88) with buff (45) margins and reverse hazel (88) with buff (45) margins. Colonies on PDA at 25 ˚C, good sporulate, velvety to lanose, folded, vinaceous buff (86), and reverse olivaceous grey (121) with olivaceous buff (89) margins. Colonies on MEA at 25 ˚C, good sporulate, velvety to lanose, folded at a center with radiate-wrinkled margin, vinaceous buff (86), and reverse honey (64) with greenish glaucous (90) margins. Colonies on OA at 25 ˚C, good sporulate, velvety, indistinctly zonate, hazel (88) with isabelline (65) margin. Conidiophores abundant, unbranched or branched, melanized, asperulate, 25.0– (51.7)–76.6 × 0.7–(1.6)–2.1 μm. Fertile hyphae hyaline, dichotomously branched, 1.2–(1.4)–1.5 μm diam. Conidia thick-walled, hyaline to lightly pigmented, subglobose to elongate, spinulose, 1.6–(2.0)–2.9 × 1.7–(2.1)–2.9 μm. Chlamydospores absent. Good growth at 20–30 ˚C and pH 3–9, maximal growth at 25 ˚C and pH 7. Ability to form hyphal coil in ericaceous rhizodermal cell.

Etymology:

The epithet “boninense” is derived from the locality where the species was collected, the Bonin Islands, Japan.

Type:

Anijima Island , Tokyo, Japan, 2019, isolated from the roots of V. boninense (holotype, TNS-F-91409, dried culture on CMA; ex-type culture, NBRC 115392 ) .

Notes:

Phylogenetic analysis based on ITS, LSU, MCM7, and RPB1 sequences can be used to distinguish between O. boninense and related species. Oidiodendron boninense show close phylogenetic relationship with O. ramosum (29 bp differences in ITS; 10 bp in LSU; 106 bp in MCM7; 60 bp in RPB1), O. setiferum (27 bp differences in ITS; 9 bp in LSU; 100 bp in MCM7; 69 bp in RPB1), O. muniellense (28 bp differences in ITS; 10 bp in LSU; 107 bp in MCM7; 61 bp in RPB1), and O. fuscum (29 bp differences in ITS; 10 bp in LSU; 107 bp in MCM7; 61 bp in RPB1). Oidiodendron boninense can be distinguished from O. ramosum , O. setiferum , and O. muniellense by the absence of conidiophores bearing melanized appendages at their apices and be done from O. fuscum by its longer asperulate conidiophores and spinulose conidia.

Figures

FIGURE 2. Morphology of Oidiodendron boniense sp. nov. A. 28 day old colony on CMA. B. 28 day old colony on PDA. C. 28 day old colony on MEA. D. 28 day old colony on OA. E. Conidia. F. Scanning electron micrograph of conidia. G‒H. Conidiophores, fertile hyphae, and conidia. I. Hyphal coils within hair roots of Vaccinium virgatum. Hyphae are stained brown. Scale bar: E, G‒I = 10 µm, F = 5 µm.

FIGURE 3. Line drawings of the microscopic morphology of Oidiodendron boniense sp. nov. A‒B. Conidia. C‒E. Conidiophores, fertile hyphae, and conidia. Scale bar: A‒B = 5 µm, C‒E = 10 µm.