Chrysozyma rhododendri Q.M. Wang, F.Y. Bai & A.H. Li, 2020

Li, A. - H., Yuan, F. - X., Groenewald, M., Bensch, K., Yurkov, A. M., Li, K., Han, P. - J., Guo, L. - D., Aime, M. C., Sampaio, J. P., Jindamorakot, S., Turchetti, B., Inacio, J., Fungsin, B., Wang, Q. - M. & Bai, F. - Y., 2020, Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species, Studies In Mycology 96, pp. 17-140 : 127-129

Chrysozyma rhododendri Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828853. Figs 17H and 18P .

Etymology: the specific epithet rhododendri refers to Rhododendron , the plant genus from which the type strain was isolated.

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are cylindrical to long ellipsoidal, 1.9–3.7 × 7.5– 12.5 μm and single, budding is polar ( Fig. 18P ), a sediment is present. After 1 mo at 17 °C, a ring and sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is cream, mucoid, smooth and glossy. The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are not produced.

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, sucrose, maltose, cellobiose, trehalose, raffinose, melezitose, D-xylose, L-arabinose, ethanol, D-mannitol, D-glucitol, Methyl-α- D-glucoside and salicin are assimilated as sole carbon sources. Galactose, Lsorbose, lactose, melibiose, inulin, soluble starch, D-arabinose, D-ribose, L-rhamnose, D-glucosamine, N-Acetyl-D-glucosamine, methanol, glycerol, erythritol, ribitol, galactitol, DLlactate, succinate, citrate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate, sodium nitrite, L-lysine, ethylamine hydrochloride and cadaverine dihydrochloride are assimilated as sole nitrogen sources. Maximum growth temperature is 22– 23 °C. Growth in vitamin-free medium is positive. Starch-like substances are not produced. Growth on 50 % (w/w) glucose-yeast extract agar is negative. Urease activity is positive. Diazonium Blue B reaction is positive.

Physiologically, Ch. rhododendri differs from its closely related species Ch. iridis in its ability to assimilate raffinose, D-xylose, Larabinose, ethanol and Methyl-α- D-glucoside ( Table S1.34 ).

Typus: China, Tibet, obtained from a leaf of Rhododendron sp. , Sep. 2014, Q.-M. Wang (holotype CGMCC 2.5821 T preserved in a metabolically inactive state, ex-type CBS 15583 = XZ160D3).

Figures

Fig. 17. SEM image of vegetative cells grown in YM broth for 5 d at 17 °C. (A, B) Ros. cystopteridis CGMCC 2.2615T, A Bars = 10 μm, B Bars = 2 μm; (C) Ros. motuoensis CGMCC 2.5819T, Bars = 10 μm; (D) He. tridentata CGMCC 2.5602T, Bars = 10 μm; (E, F) He. cylindrica CGMCC 2.5650T, E Bars = 20 μm, F Bars = 5 μm; (G) Ya. terricola CGMCC 2.5820T, Bars = 10 μm; (H) Ch. rhododendri CGMCC 2.5821T, Bars = 5 μm.

Fig. 18. Vegetative cells grown in YM broth for 5 d at 17 °C and ballistoconidia produced on corn meal agar after 7 d at 17 °C. (A, B) Rh. jianfalingensis CGMCC 2.3532T; (C, D) Rh. fuzhouensis CGMCC 2.4435T; (E) He. tridentata CGMCC 2.5602T; (F) He. cylindrica CGMCC 2.5650T; (G) Mic. swertiae CGMCC 2.3533T; (H) Ya. terricola CGMCC 2.5820T; (I) O. nepetae CGMCC 2.5824T; (J) O. dicranopteridis CGMCC 2.3441T; (K, L) Ch. pseudogriseoflava CGMCC 2.5629T; (M, N) Ch. sambuci CGMCC 2.2618T; (O) Ch. iridis CGMCC 2.2769T; (P) Ch. rhododendri CGMCC 2.5821T. Bars = 10 μm.