Rhizopus oryzae Went & Prins. Geerl., Verh. K. Akad. Wet.

Ganeshalingam, Archchana & Daranagama, Dinushani A., 2022, First comprehensive study on distribution frequency and incidence of seed-borne pathogens from cereal and legume crops in Sri Lanka, Phytotaxa 531 (3), pp. 267-281 : 276

Rhizopus oryzae Went & Prins. Geerl., Verh. K. Akad. Wet. , tweede sect. 4 (2): 16 (1895)

Index Fungorum registration number: 433253

Colonies on PDA are rapidly growing, covered the entire 9 cm plate in four days at 28–30 0 C, white, turned brownish with sporulation and aging, reverse white, filamentous, margin filiform, appearance hairy or cottony, mycelia raised ( Figure 1a, b , 2d, e , 3a, b , 4a, b .). Sporangiophore 1–2.5 mm (x̄=1.8) in length and 8–14 μm (x̄=9) in width, branched, aseptate, stout with dichotomous or trichotomous branching ( Figure 4c .), smooth-walled and ribbon-like, rhizoids present at the base. Sporangia 160–240 μm (x̄=212) diam., globose, black ( Figure 1c , 2f , 3c .).

Notes: The Rhizopus isolate from Arachis hypogea kernel ( MZ314418 ) and the seed coat ( MZ323688 ) showed 99% percentage similarity to Rhizopus oryzae accessions MH865580 (identity: 582/584, gaps: 2/584) and KJ417528 (identity: 630/635, gaps: 3/635) respectively. The isolate ( MZ277274 ) from Oryza sativa showed 97.90% similarity to KJ417528 (identity: 605/618, gaps: 2/618). This isolate ( MZ277277 ) from Vigna radiata shared a similarity index of 97.93% to Rhizopus oryzae reference sequence MH857485 (identity: 569/581, gaps: 1/581).

Figures

FIGURE 1. Colony morphology (upper surface and lower surface) and microscopic features (conidia, conidiophore, and spores) respectively of fungal pure cultures from Arachis hypogea kernel on PDA after 10 days at 28–30 0C; a–c Rhizopus oryzae, d–f Aspergillus oryzae, g–i Aspergillus niger, j–l Macrophomina phaseolina, m–o Talaromyces oumae-annae and p–r Aspergillus niger.

FIGURE 2. Colony morphology (upper surface and lower surface) and microscopic features (conidia and conidiophore) respectively of fungal pure cultures from Arachis hypogea seed coat on PDA after 10 days at 28–30 0C; a–c Aspergillus niger, d–f Rhizopus oryzae and g–i Aspergillus niger.

FIGURE 3. Colony morphology (upper surface and lower surface) and microscopic features (conidia and conidiophore) respectively of fungal pure cultures from Oryza sativa on PDA after 10 days at 28–30 0C; a–c Rhizopus oryzae, d–f Bipolaris sivanesaniana, g–i Daldinia eschscholtzii and j–l Orbilia foliicola.

FIGURE 4. Colony morphology (upper surface and lower surface) and microscopic features (conidia and conidiophore) respectively of fungal pure cultures from Vigna radiata on PDA after 10 days at 28–30 0C; a–c Rhizopus oryzae.