Termitomyces microcarpus (Berk. & Broome) R. Heim (1941:147)

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 : 202-205

Termitomyces microcarpus (Berk. & Broome) R. Heim (1941:147)

Index Fungorum: 521639

Figure 12 and Figure 13

Basidiomata small. Pileus 1.2–1.5 cm diameter, conic when young and then plano-convex to uplifted at maturity, tiny obtuse perforatorium; surface white (4A1) to grey (4B1) and brownish orange (5C3) or dark blonde (5D4) at the center at maturity, smooth, glabrous, slightly striated, margin smooth, straight, often radially splitting. Lamellae free, white (4A1) to creamy, 1 mm wide, crowded with lamellulae of 4 lengths. Stipe 15 cm long, 0.5 cm wide, cylindrical, central, surface white to orange-white (6A2) or orange grey (5B2), smooth and glabrous. Annulus absent.

Basidiospores 4.3–8.2 × 3.1–5 μm, ovoid to ellipsoid, smooth, thin-walled, inamyloid. Basidia 13–28 × 4.8–10 μm, clavate to sub-cylindric with four sterigmata, inamyloid. Hymenophoral trama regular. Cheilocystidia rare, 28–39 × 9.2–17.2 μm, clavate to pyriform, inamyloid, smooth, thin-walled. Pleurocystidia rare, 22–35 × 10–16.8 μm, similar to cheilocystidia. Pileipellis is an epicutis with narrow, radial hyphae.

Ecology and distribution:— It grows solitary on clayey soil. It is distributed in countries such as China, Cameroon, Ethiopia, Ghana, India, Japan, Laos, Malawi, Malaysia, Nepal, Pakistan, Philippines, Sri Lanka, South Africa, Tanzania, and Thailand.

Material examined:— Sri Lanka. Western Province: Colombo District, Nugegoda , 79°54’8.36”E 6°51’7.62”N, 18 th September 2022, Naduni Dasanthi, GenBank accession number: OR139835 , Specimen number WH13 (USJ-GMBU-001) .

Phylogenetic analyses of Termitomyces

A total of 33 sequences of Termitomyces were included in the phylogenetic tree. Lyophyllum connatum and L. infumatum were used as the outgroups. According to the results, four out of the eight specimens belonged to the genus Termitomyces , and the resulting phylogenetic tree is shown in Figure 14 .

The molecular phylogenetic analyses revealed that the sequence of WH13 (USJ-GMBU-001) clustered with T. microcarpus (KP780436; UOC KAUNP MK 04 voucher) from Sri Lanka in clade D with bootstrap support of 96% at the node. The results confirmed the identity of the WH 13 specimen as T. microcarpus .

According to the resulting phylogenetic tree ( Figure 14 ), the collected specimens RH29 (USJ-GMBU-003), RH30 (USJ-GMBU-004), and RH33 (USJ-GMBU-006) are phylogenetically closely related to T. heimii confirming their identities. They formed a monophyletic clade with T. heimii (KP943503; UOC MAT MT 01 voucher) from Sri Lanka and T. heimii ( MN 160309; TERM 055 voucher) from Thailand with bootstrap support of 90% at the node of the clade E. A voucher specimen of T. heimii ( MN 160309; TERM 055) from Thailand is present as a sister taxon to the subclade with the collected T. heimii specimens (USJ-GMBU-003, USJ-GMBU-004 and USJ-GMBU-006) and T. heimii ( KP 943503) with high bootstrap support (100%). This suggests that the Sri Lankan collections are more closely related to each other than to the T. heimii from Thailand. Even though T. heimii specimen USJ-GMBU-006 ( OR 139836) was collected at the immature stage and had inadequate morphological characteristics, its identification was resolved to the species level by molecular data.

Notes:— Termitomyces heimii has been reported from Kenya, Ivory Coast, India, Malaysia, Nepal, Pakistan, China, Thailand, Myanmar, Bangladesh, and Sri Lanka so far. Termitomyces microcarpus was originally described from Peradeniya, Sri Lanka ( Turnbull & Watling 1999), and it is widely distributed in Cameroon, Tanzania, South Africa, Malawi, Ethiopia, Japan, Ghana, Nepal, Malaysia, India, Pakistan, Philippines, China, Thailand, and Laos ( Paloi et al. 2023). Termitomyces microcarpus and T. heimii are some of the most renowned wild edible mushrooms consumed by Sri Lankans as well as communities in India, China, Laos, Nepal, Thailand and Malaysia ( Gamage & Ohga 2018, Paloi et al. 2023). Sri Lanka has no commercial cultivation of these mushrooms (Guansekara et al. 2021). Research findings show that T. microcarpus and T. heimii contain diverse medicinally significant secondary metabolites, suggesting their potential applications as antioxidants, immunomodulators, antitumor agents, and antimicrobials ( Johnsy & Kaviyarasan 2014, Hsieh & Ju 2018).

Figures

FIGURE 12. Termitomyces microcarpus (Herbarium code: USJ-GMBU-001). a,b. Mature basidiomata in situ. Scale bars = 1 cm. Photography by Naduni Dasanthi.

FIGURE 13. Termitomyces microcarpus (Herbarium code: USJ-GMBU-001). a. Spores. b. Basidia. c. Pleurocystidia. d. Cheilocystidia. Scale bars: a = 5 µm; b, c, d = 10 µm. Illustration by Aseni Ediriweera.

FIGURE 14.A phylogenetic tree for ITS sequences was constructed using maximum likelihood (ML) analysis for the genus Termitomyces. The newly generated strains are 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 Lyophyllum connatum and L. infumatum.