Filobasidium pseudomali C. Y. Cai & F. L. Hui sp. nov.

Fig. 3 A

Etymology.

The specific epithet pseudomali refers to similar colony morphological and physiological characteristics to that of Filobasidium mali.

Typus.

China • Guizhou Province, Guiyang City, Guiyang Medicinal Botanical Garden, in the phylloplane of Photinia sp., August 2022, L. Zhang and F. L. Hui, NYNU 228108 (holotype GDMCC 2.305 T preserved in a metabolically inactive state in Guangdong Microbial Culture Collection Center, culture ex-type PYCC 9928 deposited in the Portuguese Yeast Culture Collection).

Description.

On YM agar, after 7 days at 20 ° C, the streak culture is gray-cream, mucoid, smooth, and glossy. The margin is entire. On YM agar, after 7 days at 20 ° C, cells are globosal and ellipsoidal, 3.8–6.4 × 5.2–8.4 μm, and single, budding is polar. After 1 month at 20 ° C, a ring and sediment are present. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Sexual structures are not observed on PDA, CM agar, and YCBS agar for two months. Ballistoconidia are not produced. Glucose fermentation is absent. Glucose, inulin, sucrose, raffinose, melibiose, galactose, lactose, trehalose, maltose, melezitose, methyl-α-D-glucoside, cellobiose, L-sorbose, L-rhamnose, D-xylose, L-arabinose, D-arabinose, 5 - keto-D-gluconate, ethanol, ribitol, galactitol, D-mannitol, D-glucitol, myo-inositol, succinate, citrate, D-gluconate, 2 - keto-D-gluconate, D-glucuronate, and glucono- 1, 5 - lactone are assimilated as sole carbon sources. Salicin, D-ribose, methanol, glycerol, erythritol, DL-lactate, D-glucosamine, and N-acetyl-D-glucosamine are not assimilated. Nitrate, nitrite, ethylamine, and L-lysine (weak) are assimilated as sole nitrogen sources. Cadaverine is not assimilated. Maximum growth temperature is 30 ° C. Growth in vitamin-free medium is positive. Growth on 50 % (w / w) glucose-yeast extract agar is negative. Starch-like substances are not produced. Urease activity is positive. Diazonium Blue B reaction is positive.

Additional strain examined.

China • Guizhou Province, Guiyang City, Guiyang Medicinal Botanical Garden, in the phylloplane of Litsea cubeba, August 2022, L. Zhang and F. L. Hui, NYNU 22986.

GenBank accession numbers.

Holotype GDMCC 2.305 T (ITS: OP 581930, D 1 / D 2: OP 566876, RBP 1: OR 963293, RBP 2: PP 151258); additional strain NYNU 22986 (ITS: PP 108743, D 1 / D 2: PP 108744, RBP 1: PP 841943, RBP 2: PP 151259).

Note.

Filobasidium pseudomali sp. nov. can be physiologically distinguished from its closest known species, F. mali, by its ability to assimilate inulin and citrate and its inability to assimilate salicin and cadaverine. Additionally, F. pseudomali nov. can grow in a vitamin-free medium, while F. mali cannot (Table 3).

1, F. pseudomali sp. nov.; 2, F. mali; 3, F. globosum; 4, F. castaneae sp. nov.; 5, F. qingyuanense sp. nov.; 6, F. dingjieense; +, positive reaction; –, negative reaction; d, delayed positive; w, weakly positive; n, data not available. All data from this study, except * which were obtained from the original description (Li et al. 2020).