Volvariella volvacea (Bul.) Singer (1951:401)

Dasanthi, Naduni, Thambugala, Kasun M., Karunarathna, Samantha C., Ediriweera, Aseni, Munasinghe, Helani, Elgorban, Abdallah M., Harischandra, Hiruni & Dharmasena, Buddhika P., 2024, Morphological and molecular insights into the hidden edible mushroom diversity in Sri Lanka, Phytotaxa 645 (3), pp. 192-213 : 205-206

Volvariella volvacea (Bul.) Singer (1951:401)

Index Fungorum: 307802

Figure 15 and Figure 16

Basidiomata small to medium. Pileus convex when young, broadly convex at maturity, 60–65 mm in diameter, surface smooth, finely velutinous, yellowish grey (3B2) to sand brown (4B3), or beige (4C3), non-hygrophanous, center brown (6E5) to greyish brown (6E3), umbonate, margin eroded, sand brown (4B3) to beige (4C3), thin, slightly decurved to straight, context soft, white (4A1) to light yellow (4A5). Lamellae free, crowded, ventricose, thin, soft, orange white (6A2) turning pinkish white (7A2) or light orange with maturity, edge fimbriate, concolourous with faces; lamellulae present in two to three tiers. Stipe 7–7.5 cm long, 1–1.5 cm wide, central, equal, flexuous, grey (6B1) to light yellow, entirely pubescent; context white (4A1) to brownish yellow (4A5); annulus absent. Volva 3 cm high, moderately thick, saccate, light brown to greyish brown (6E3).

Basidiospores 6–9.2 × 4.5–5.4 μm, ellipsoid to elongate, thick-walled, hyaline. Basidia 31–35 × 7.3–9.0 µm, broadly clavate, hyaline, 4-spored. Pleurocystidia 40–110 × 15–30 μm, clavate to lageniform, thin-walled, hyaline. Cheilocystidia 40–70 × 10–15 μm, clavate to broadly lageniform, thin-walled, hyaline. Stipitipellis is a cutis, 20–55 × 6–12 µm of terminal elements.

Ecology and distribution:— It grows solitary on paddy straw with moisture. Volvariella volvacea is reported to be from tropical and subtropical regions, viz. China, India, Indonesia, Madagascar, Nigeria, Philippines, Sri Lanka, and Thailand.

Material examined:— Sri Lanka. Sabaragamuwa Province: Rathnapura District, Balangoda , 80°44’46.35”E 6°41’13.58”N, 30 th September 2022, Naduni Dasanthi, GenBank accession number: OR139837 , Specimen number: RH32 (USJ-GMBU-005) .

Phylogenetic analyses of Volvariella

A total of 59 sequences of Volvariella species were used in phylogenetic analyses. Cantharocybe virosa and Cuphophyllus yacurensis were chosen as the outgroup taxa for the phylogenetic tree. Phylogeny proved the identity of the specimen RH32 (USJ-GMBU-005) as V. volvacea as it clustered with V. volvacea in clade F ( Figure 17 ). In the phylogenetic tree, the species V. volvacea forms a single major clade (Clade F) with a bootstrap value of 93% to the sister taxon V. diplasia ( MH 858454). In clade F, the collected V. volvacea (OR139837; USJ-GMBU-005) occurs as a sister taxon to the subclade containing V. volvacea (KT899356; IR 0031), V. volvacea ( HM 367073; NIH 1001) and V. volvacea (AY632077; OE-55) from Iran, USA, and India respectively with a bootstrap value less than 70% indicating poor branch support. This is the first study on the molecular characterization of V. volvacea in Sri Lanka.

Notes:— Volvariella volvacea is widely distributed in tropical and subtropical regions, including Sri Lanka, India, China, Thailand, Philippines, Indonesia, Madagascar, and Nigeria ( Coomaraswamy 1979). In Sri Lanka, morphological characterization of V. volvacea was done by Pegler (1986), but the current work is the first study conducted on molecular characterization of V. volvacea in Sri Lanka. Currently, commercial cultivation of V. volvacea can be seen in Asian countries such as China, India, the Philippines, and Thailand ( Kumla 2022). Moreover, V. volvacea is commercially grown in Sri Lanka, and several studies have been undertaken to enhance cultivation methods for this mushroom species in the country ( Rajapakse 2011, Nissanka et al. 2013). Volvariella volvacea is a rich source of proteins, vitamins, minerals, antioxidants, and other bioactive compounds that have anti-inflammatory, antidiabetic, antitumor, antibacterial, and immunomodulatory properties ( Wasule et al. 2023).

Figures

FIGURE 15. Volvariella volvacea (Herbarium code: USJ-GMBU-005). a,b. Mature basidiomata in situ. Scale bars = 1.5 cm. Photography by Naduni Dasanthi.

FIGURE 16. Volvariella volvacea (Herbarium code: USJ-GMBU-005). a. Basidiospore. b. Basidia. c. Pleurocystidia. d. Cheilocystidia. e. Pileipellis terminal elements. Scale bars: a, b = 5 µm; c,d,e = 10 µm. Illustration by Aseni Ediriweera.

FIGURE 17. A phylogenetic tree for ITS sequences was constructed using maximum likelihood (ML) analysis for the genus Volvariella. The newly generated strain is in red. ML bootstrap values are given at the nodes. Bootstrap support values equal to or higher than 70% are provided. The tree is rooted with Cantharocybe virosa and Cuphophyllus yacurensis.