Leptobacillium xianyushanense Ming J. Chen, Xiao Y. Chang & B. Huang, 2024

Chang, Xiao-Yun, Hu, Jiang-Xin, Shen, Dan-Qi, Han, Yi-Ren, Liu, Yu-Jun, Huang, Bo & Chen, Ming-Jun, 2024, Morphological and molecular analysis reveal a new species in the genus Leptobacillium (Cordycipitaceae, Hypocreales) isolated from Camellia oleifera rhizosphere, Phytotaxa 664 (4), pp. 281-289 : 286

Leptobacillium xianyushanense Ming J. Chen, Xiao Y. Chang & B. Huang , sp. nov. Fig. 2

MycoBank No: MB 850134

Etymology: xianyushanense referred to the locality where the type specimen was collected, Xianyu Mountains, China.

Systematic position: Fungi, Ascomycota, Pezizomycotina, Sordariomycetes, Hypocreomycetidae, Hypocreales , Cordycipitaceae

Typification: CHINA, Anhui Province: Xianyu Mountain National Nature Reserve, isolated from rhizosphere of Camellia oleifera , April 2021, J.X. Hu, Y.R. Han & M.J. Chen, isolated culture on PDA, culture ex-holotype RCEF6795. Preserved in Research Center for Entomogenous Fungi (RCEF). GenBank sequence data for RCEF6795: ITS=OQ780930, LSU=OQ780931.

Culture characteristics: Colonies on PDA rather slow growing, reaching 20–36 mm in diameter in 14 days at 25 °C, white, irregular floccose surface characterized by divergent cracks. Reverse orange to orange-brown, ochraceous, pale luteous, milky white to dark buff. Conidiophores bearing mainly long solitary phialides, rarely with branches of one or two phialides. Phialides mainly solitary, slender, tapering toward tip, 24.7–28.5 × 1.5–1.9 μm. Conidia forming very long, slender and inconspicuous chains, narrowly cylindrical (rod-shaped) to slightly fusiform, 3.8–5.6 × 0.5–1.2 μm. The first-formed conidium is usually shorter, clavate to drop-shaped, with a rounded distal end. Chlamydospores absent. Octahedral crystals not observed.

Additional specimens examined: CHINA, Anhui Province: Xianyu Mountain National Nature Reserve, isolated from rhizosphere of Camellia oleifera , April 2021, J.X. Hu, Y.R. Han & M.J. Chen, isolated culture on PDA, culture RCEF6793 was preserved in Research Center for Entomogenous Fungi (RCEF).GenBank sequence data for RCEF6793: ITS=OQ780699, LSU=OQ780702.

Notes: Leptobacillium coffeanum , L. symbioticum , and L. filiforme exhibit phylogenetic affinities with L. xianyushanense . However, the length of conidia in the new species (3.8–5.6 μm) notably is divergent that of both L. coffeanum (2.2–3.8 μm) and L. filiforme (7.2–12.5 μm). Although L. xianyushanense shares morphological similarities with L. symbioticum , a closer examination of phialide structure provides a clear differentiation. The new species presents phialides with elongated and slender necks, setting it apart from L. symbioticum ( Table 2). In addition to phialide morphology, colony attributes provide further differentiation between L. xianyushanense and L. symbioticum . The colonies of L. symbioticum display a relatively flat configuration, accompanied by a white reverse side. In contrast, colonies of L. xianyushanense exhibit an irregular surface characterized by divergent cracks, coupled with an orange to orange-brown reverse side ( Table 2).

Figures

FIGURE 2. Morphology of Leptobacillium xianyushanense sp. nov. a–b. Upper and reverse views of the culture on PDA. c. Conidia. d–e. Sporulation pattern. f. Phialides. g. Cylindrical to fusiform conidia in long chains. Scale bars: d = 10μm, c, e, f, g = 5μm.