Kondoa myxariophila J.P. Sampaio, Q.M. Wang & F.Y. Bai, 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 : 106-107

Kondoa myxariophila J.P. Sampaio, Q.M. Wang & F.Y. Bai sp. nov. MycoBank MB828799. Figs 12P and 13 .

Etymology: the specific epithet myxariophila refers to the association of the novel taxon with the fruiting bodies of Myxarium nucleatum ( Auriculariales ).

Sexual characteristics: The sexual stage is observed PDA and MYP plates incubated at 20 °C for 8 – 12 wk and occurs in individual strains in the absence of mating. Hyphae are 3– 5 μm in diameter and have clamp connections. Basidia are cylindrical, transversely-septate, usually four-celled and measure 40– 60 × 7.5– 5 μm ( Fig. 13A, C ). Basidiospores are formed at the end of basidial sterigmata, measuring 10– 5 μm in length. Basidiospores are oval, measure 11 –9 × 7 –5 μm ( Fig. 13B ), are forcefully ejected (ballistospores) and germinate by budding. Haustorial branches are conspicuously formed and occur laterally on hyphae ( Fig. 13C, D ).

Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal to ovoid, measure 3 – 4 × 4 – 6 μm and occur single or in pairs and budding is polar ( Fig. 12P ). A sediment is formed. After 1 mo at 17 °C, a pellicle and a sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is pale yellow, butyrous, semi-glossy and smooth. The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Ballistoconidia can be produced in solid medium (CMA) but are rare and measure 4 – 5 × 5 – 8 μm ( Fig. 13E ).

Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, sucrose, maltose, trehalose, melibiose (variable), cellobiose (variable), raffinose (variable), melezitose, soluble starch, D-xylose, L-arabinose (delayed and weak), Darabinose (delayed and weak), D-ribose (variable), L-rhamnose (delayed and weak), D-glucosamine (variable), glycerol (delayed and weak), ribitol (variable), salicin (variable), D-mannitol (delayed and weak), D-glucitol (delayed and weak), succinate (delayed and weak) and citrate (weak) are assimilated as sole carbon sources. Galactose, L-sorbose, lactose, inulin, methanol, ethanol, erythritol, galactitol, Methyl-α- D-glucoside, DL-lactate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate (variable), sodium nitrite (variable), ethylamine hydrochloride (delayed and weak) and cadaverine dihydrochloride (delayed and weak) are assimilated as sole nitrogen sources. L-lysine is not assimilated. Maximum growth temperature is 22– 25 °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, Kon. myxariophila differs from its closest relatives, Kon. daliangziensis, Kon. ribitolophobia and Kon. gutianensis , in its inability to assimilate L-lysine and its ability to assimilate soluble starch and D-xylose ( Table S1.17 ).

Typus: Portugal, Sesimbra, obtained from the fruiting body of Myxarium nucleatum ( Auriculariales ), Nov. 1992, J.P. Sampaio

(holotype PYCC 5509 T preserved in a metabolically inactive state, ex-type CBS 8379 = ZP 337).

Note: Besides several sexual strains isolated with the ballitoconidium-fall method from basidiocarps of Myxarium nucleatum in Portugal (PYCC 5509 = ZP 337; PYCC 8354 = ZP 338; and PYCC 8305 = ZP 352) in 1992 and 1996, another strain was isolated from the leaf of an unidentified plant, collected in Germany in September 2005 (CGMCC 2.3106 = CBS 15468). Although a sexual stage has not been reported for the culture isolated in Germany, these four strains have similar ITS sequences. Therefore, Kon. myxariophila appears to be capable to engage in mycoparasitism because it produces haustorial branches and is ecologically associated with other fungi. Nevertheless, the mycoparasitic strategy might be combined with a saprobe lifestyle in the phylloplane since Kon. myxariophila is also able to produce ballistoconidia and is also found in association with plant leafs. Similarly to the other two sexual species in the genus, Kon. aeria and Kon. malvinella , Kon. myxariophila does not produce teliospores, produces transversely-septate basidia and its basidiospores are forcefully discharged (ballistospores).

Figures

Fig. 12. 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) Fi. mucilaginum CGMCC 2.3463T; (B) Pha. aurantiaca CGMCC 2.5601T; (C, D) Kon. cylindrica CGMCC 2.3102T; (E, F) Kon. chamaenerii CGMCC 2.2652T; (G, H) Kon. foliicola CGMCC 2.3100T; (I, J) Kon. arboricola CGMCC 2.2621T; (K, L) Kon. lulangica CGMCC 2.2762T; (M, N) Kon. daliangziensis CGMCC 2.5610T, (O) Kon. ribitophobia CGMCC 2.4441T; (P) Kon. myxariophila CBS 8379T. Bars = 10 μm.

Fig. 13. Vegetative cells, ballistoconidia and the sexual stage of Kon. myxariophila CBS 8379T. (A) Basidia; (B) Basidiospores; (C, D) Haustorial branches; (E) Ballistoconidia. Bars = 10 μm.