Calvatia candida (Rostk.) Hollós (1902:112)

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 : 195-197

Calvatia candida (Rostk.) Hollós (1902:112)

Index Fungorum: 122114

Figure 1 and Figure 2

Gasterocarp small. Pseudostipe rounded at base, ostiole absent, Exoperidium buttercup yellow (4B7). Gasterocarp 35 mm high, 40 mm diameter, subglobose, with the presence of pseudostipe which is 25 mm in height and 28 mm in width. With maturity, exoperidium turns dull yellow (3B3), thin, smooth, and membranous, forming light yellowbrown crowded patches. Endoperidium attached to the exoperidium. Gleba smaller, blonde color (4C4) when mature. Subgleba, larger than gleba, occupies more than 2/3 rd size of the gasterocarp. Basidiospores 2.3 × 3.2 μm diameter, globose to sub-globose, echinate, with short spines, and pedicellate.

Ecology and distribution:— It grows solitary on clayey soil with leaf litter. Calvatia candida is reported from regions including Australia, Costa Rica, Cuba, India, Israel, New Zealand, Sri Lanka (this study), the USA, and several European countries, including Germany, Hungary, and Italy.

Material examined:— Sri Lanka. Sabaragamuwa Province: Rathnapura District, Balangoda , 80°44’58.96”E 6°40’52.56”N, 7 th August 2022, Naduni Dasanthi, GenBank accession number: OR139841 , Specimen number: RH24 (USJ-H-014) .

Phylogenetic analyses of Calvatia

A total of 40 sequences retrieved from GenBank were used for phylogenetic analysis. The outgroup taxon used in the phylogenetic tree is Chlorophyllum pseudoglobosum . In the phylogenetic tree ( Figure 3 ), the ITS sequence ( OR 139841) acquired from the specimen RH24 (USJ-H-014) clustered with Calvatia candida sequences ( MH 916575; C1 and GU939632; PB 101) from India that form a monophyletic clade (Clade A) with strong bootstrap support (99%) confirming its identity. The C. candida (GU939632; PB 101) is a sister taxon to the subclade having the C. candida (OR139841; USJ-H-014) and C. candida ( MH 916575; AMH 10029) in clade A. Accordingly, C. candida OR 139841 (USJ-H-014) and C. candida ( MH 916575; AMH 10029) are more evolutionary closely related.

Both C. candida and C. holothurioides are sister clades with strong bootstrap support (100%) on the node, similar to the phylogenetic trees in Kshirsagar et al. (2020) and Gunasekaran et al. (2018), indicating a close evolutionary relationship between them. Furthermore, Calvatia candida (KF668328; ASIS 22727) from South Korea is clustered amongst the sequences of C. holothurioides . A BLASTn search comparing the sequence of C. candida (KF668328; ASIS 22727) with the closely related sequences of taxa obtained from the NCBI database showed 98.85% identity with C. holothurioides voucher LE 287408 (Query cover 100% and E value 0). The identity of C. candida (KF668328; ASIS 22727) was not confirmed by phylogenetic analyses in published literature. Therefore, morphological characterisation and phylogenetic analyses are required to verify the identity of C. candida (KF668328; ASIS 22727).

Notes:— Calvatia candida is reported for the first time from Sri Lanka, and this is the first molecular phylogenetic study on Calvatia species in Sri Lanka. This species is commonly found in regions including Israel, the USA, India, Cuba, Costa Rica, Australia, New Zealand and several European countries, including Germany, Hungary, and Italy ( Krakhmalnyi et al. 2023). All Calvatia species are edible at the immature stage before the spores mature and the gleba remains firm and white ( Johannes & Abraham 2009). While C. candida is a wild edible mushroom, no documentation in published literature regarding its commercial cultivation exists. Moreover, C. candida contains bioactive compounds such as alkaloids, steroids and terpenoids that exert antioxidant and antitumor activities ( Wu et al. 2016).

Figures

FIGURE 1. Calvatia candida (Herbarium code: USJ-H-014). a,b. Mature basidiomata in situ. Scale bars = 2 cm. Photography by Naduni Dasanthi.

FIGURE 2. Calvatia candida (Herbarium code: USJ-H-014). a. Spores; Scale bars: a = 1.5 µm. Illustration by Aseni Ediriweera.

FIGURE 3. A phylogenetic tree for ITS sequences was constructed using maximum likelihood (ML) analysis for the genus Calvatia. 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 Chlorophyllum pseudoglobosum.