Nigrospora philosophiae-doctoris Raza, Qian Chen & L. Cai

Nigrospora philosophiae-doctoris Raza, Qian Chen & L. Cai View in CoL , Studies in Mycology 101: 491 (2022)

Fig. 16 View Figure 16

Description.

Sexual morph: Not observed. Asexual morph: Hyphae interwoven, initially hyaline, becoming pale brown to yellowish-brown with age, darkening to light brown near sporulating regions, septate, thick-walled, frequently branched, 1.5–4.8 µm in diameter. Conidiophores reduced to conidiogenous cells. Conidiogenous cells initially hyaline, maturing to pale brown or yellowish-brown, predominantly solitary but occasionally clustered (2–3 cells), phialidic or subglobose, 2.5–11.4 × 3.0–8.1 µm (av. ± S. D. = 8.1 ± 2.2 × 7.1 ± 2.0). Conidia borne singly on hyphae, rarely in sparse clusters, initially light yellowish-brown, turning black or dark brown at maturity, smooth-walled, aseptate, subglobose to ellipsoidal, 13.7–18.9 × 10.4–17.8 µm (av. ± S. D. = 16.3 ± 1.1 × 13.4 ± 1.9).

Specimens examined.

China • Beijing City, Changping District, Dingling Scenic Area, Ming Tombs , 40°17'28"N, 116°14'31"E, on the healthy strobili of Juniperus chinensis , 31 March 2025, Z. X. Bi, BJFC -S 2577 , living culture CFCC 72628 GoogleMaps ; China • Beijing City, Changping District, Dayu Mountain Scenic Area, Ming Tombs , 40°18'20"N, 116°12'4"E, on the diseased scale leaves with lesions of Platycladus orientalis , 23 October 2024, Z. X. Bi & M. H. W, BJFC -S 2576 , living culture CFCC 72637 GoogleMaps .

Notes.

Nigrospora philosophiae-doctoris was first isolated from Disporum sessile ( Colchicaceae ) ( Chen et al. 2022). Petrović et al. (2023) demonstrated that N. philosophiae-doctoris is a causal agent of olive leaf spot disease. Subsequently, Yan et al. (2025) isolated this species from lesions on Camellia japonica and reported it as a novel pathogen causing camellia leaf spot. Phylogenetic analyses confirmed that the two strains isolated in this study, CFCC 72628 and CFCC 72637 , clustered within the same clade as N. philosophiae-doctoris (ex-type strain CGMCC 3.20540) with strong statistical support ( ML / BI = 100 / 1) (Fig. 2 View Figure 2 ). Morphologically, these strains exhibited conidiophores reduced to conidiogenous cells, mostly solitary, 2.5–11.4 × 3.0–8.1 µm (literature range: 4–9.5 × 3–7.5 µm); conidia were black, subglobose, and measured 13.7–18.9 × 10.4–17.8 µm (literature range: 11–16 × 8–14 µm), although slightly larger than those described by Chen et al. (2022), but all other morphological characteristics aligned with those described by Chen et al. (2022). Based on integrated phylogenetic and morphological evidence, these strains were conclusively identified as N. philosophiae-doctoris . This represents the first report of this fungal species on Juniperus chinensis and Platycladus orientalis .