Spegazzinia juniperi Z. X. Bi & C. M. Tian, 2025

Spegazzinia juniperi Z. X. Bi & C. M. Tian sp. nov.

Fig. 8 View Figure 8

Etymology.

Named after the host genus, Juniperus .

Specimens examined.

China • Beijing City, Changping District, Dingling, Ming Tombs Scenic Area , 40°17'28"N, 116°14'31"E, on the healthy cones of Juniperus chinensis , 31 March 2025, Z. X. Bi, holotype BJFC -S 2582 , ex-type cultures CFCC 72647 GoogleMaps .

Description.

Isolated from healthy cones of Juniperus chinensis . Sexual morph: Not observed. Asexual morph: Hyphomycetous. On PDA medium, sporulation began after approximately 3 weeks of cultivation. Hyphae were initially colorless and transparent, turning brown at maturity, branched, septate, thick-walled, and smooth, 1.2–8.2 µm in diam. Sporodochia were dark brown to black, granular, dense, slightly moist, and 150–430 µm in diam. Conidiophore mother cells were subcylindrical, thin-walled, smooth, initially colorless and transparent, later pale brown, 4.3–9.9 × 2.5–5.2 (x ̄ = 6.6 × 4.1 µm; n = 25) µm. Conidiophores have two types of morphology, Conidiophores of α conidia are upright or curved, light brown or dark brown, unbranched, 13.0–78.6 × 1.4–3.5 µm (x ̄ = 42.3 × 2.3 µm; n = 30). Conidiophores of β conidia are colorless and transparent at the initial stage and turn light brown to dark brown after maturity, 18.4–75.5 × 1.3–3.2 µm (x ̄ = 43.7 × 2.4 µm; n = 30). The conidia have two forms: α conidia 18.2–28.3 × 15.8–24.3 µm (x ̄ = 22.6 × 19.9 µm; n = 50), stellate, 4 - celled, brown to dark brown, each cell globose to subglobose, some cells exhibit verrucose (wart-like) ornamentation and spinose projections (spines) in brown to dark brown, with spine lengths 1.8–7.6 µm, septa distinctly constricted. β Conidia 14.3–18.6 × 13.4–17.8 µm (x ̄ = 16.5 × 15.6 µm; n = 50), trifoliate (clover-shaped), discoid, 4 - celled, each cell slightly subtriangular, lacking spinose projections but with a finely roughened surface, initially hyaline and transparent, maturing to pale brown or dark brown, septa arranged in a near-cruciate (cross-like) pattern, with lighter pigmentation adjacent to septa and distinct constrictions at septal junctions.

Culture characteristics.

Cultured on PDA at 25 ° C under dark conditions for approximately 10 days, the colony diameter reaches about 60 mm. The initial colony appears grayish-white, exhibits radial growth, and adheres to the medium with a felt-like texture, displaying denser hyphae near the central region. By day 14, the colony develops concentric rings, the center becomes dark brownish-black, while the margin fades to light grayish-brown, with a regular edge. On the reverse side, the central area is black, transitioning outward to light brownish-black, and finally to light grayish-brown at the outermost edge. After 20 days, dark brown irregularly shaped sporodochia form in both the central and marginal areas of the colony.

Notes.

Phylogenetic analysis based on ITS, LSU, SSU, and tef 1 - α indicates that strains CFCC 72647 (ex-type strain) and CFCC 72641 separated from other known strains and formed a distinct clade with strong support values of 99 / 1 ( ML / BI) (Fig. 3 View Figure 3 ). This clade is clearly separated as a sister group to Spegazzinia tessarthra (support values ML / BI = 95 / 0.99) and shows close phylogenetic affinity to S. radermacherae (Fig. 3 View Figure 3 ). Morphologically, S. juniperi differs from S. tessarthra and S. radermacherae in having granular, slightly moist sporodochia. The α - conidia of S. juniperi are larger than those of S. tessarthra (18.2–28.3 × 15.8–24.3 µm vs. 15–20 × 14–18 µm), and its β - conidia are broader (13.4–17.8 µm vs. 8–12 µm) ( Tennakoon et al. 2022). Compared to S. radermacherae , S. juniperi exhibits larger α - conidia (18.2–28.3 × 15.8–24.3 µm vs. 18–22 × 17.5–20 µm), broader β - conidia (13.4–17.8 µm vs. 8–10 µm), and longer spines (1.8–7.6 µm vs. 2–3 µm) ( Jayasiri et al. 2019). Furthermore, this species could be differentiated from S. tessarthra (SH 287) at the ITS, LSU, SSU, and tef 1 - α loci with nucleotide differences of 2 / 355 bp in ITS, 7 / 890 bp in LSU, 12 / 925 bp in tef 1, and 1 / 1008 bp in SSU. It was distinguishable from S. radermacherae (MFLUCC 17-2285) at the ITS and tef 1 - α loci, showing 4 / 355 bp differences in ITS and 73 / 925 bp in tef 1 - α. Therefore, based on phylogenetic and morphological data, S. juniperi collected from Juniperus chinensis is formally described as a new species.