Nigrospora oryzae (Berk. & Broome) Petch

Nigrospora oryzae (Berk. & Broome) Petch View in CoL , J. Indian Bot. Soc. 4: 24 (1924)

Fig. 14 View Figure 14

Description.

Sexual morph: Not observed. Asexual morph: Hyphae interwoven, initially hyaline, becoming brownish with age, septate, frequently branched, 2.4–6.7 µm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells predominantly clustered but occasionally solitary on hyphae, hyaline, ampulliform to subglobose, 3.1–13.8 × 3.4–7.4 µm (av. ± S. D. = 7.3 ± 2.2 × 5.5 ± 1.0). Conidia typically aggregated in slimy masses, initially white and hyaline, gradually turning pale brown, and finally black at maturity, smooth-walled, aseptate, globose to subellipsoid, 11.7–14.8 × 10.2–13.9 µm (av. ± S. D. = 12.8 ± 0.6 × 11.9 ± 0.9).

Cultural characteristics.

On PDA medium, colonies initially appeared white and cottony. After 7 days of incubation, the mycelium developed a smoke-gray coloration, with denser growth and darker pigmentation in the central region compared to the margins. By day 20, the colonies turned grayish-black throughout.

Specimens examined.

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 2574 , living culture CFCC 72644 GoogleMaps . China • Beijing City, Changping District, Changling Scenic Area, Ming Tombs , 40°17'41"N, 116°14'24"E, on the withered leaf tips of Juniperus procumbens , 23 October 2024, Z. X. Bi, BJFC -S 2575 , living culture CFCC 72638 GoogleMaps .

Notes.

Nigrospora oryzae is recognized as both an endophyte and a pathogen causing leaf spot disease on rice ( Oryza sativa ); it commonly colonizes diverse plants and plant debris in dual roles as a pathogen and endophyte ( Wang et al. 2017; Liu et al. 2021; Liu et al. 2024). In this study, two fungal strains, CFCC 72638 and CFCC 72644 , were isolated from Platycladus orientalis and Juniperus procumbens . Based on comprehensive phylogenetic and morphological analyses, strains CFCC 72644 and CFCC 72638 were identified as N. oryzae .