Clinoconidium globosum Kakish., Nagao & Denchev, 2017

Kakishima, Makoto, Ji, Jing-Xin, Nagao, Hideyuki, Wang, Qi & Denchev, Cvetomir M., 2017, Clinoconidium globosum, nom. nov. (Cryptobasidiaceae) producing galls on fruits of Cinnamomum daphnoides in Japan, Phytotaxa 299 (2), pp. 267-272 : 269-271

Clinoconidium globosum Kakish., Nagao & Denchev , nom. nov.

MycoBank number: MB819459

Replaced name:— Sphacelotheca cinnamomi S. Hirata , Bulletin of the Faculty of Agriculture, Miyazaki University 26: 124, 1979.

Competing homonym:—non Clinoconidium cinnamomi (Syd.) R. Kirschner , in Jiang & Kirschner, Mycoscience 57: 442, 2016.

Type: — JAPAN. Kyushu, Kagoshima Prefecture, Kinko-machi, on fruits of Cinnamomum daphnoides Siebold & Zucc. , 7 December 1978, S. Hirata (holotype, not found; not in the Mycological Herbarium of Faculty of Agriculture, Miyazaki University); Kagoshima Prefecture, Osumi Peninsula, Hetsuka, 14 December 1964, S. Hirata 4014 (paratype, Mycological Herbarium of Faculty of Agriculture, Miyazaki University). Lectotype (designated here):— JAPAN. Kyushu, Kagoshima Prefecture, Hetsuka, on fruits of C. daphnoides , 14 December 1964, S. Hirata 4014 (Mycological Herbarium of Faculty of Agriculture, Miyazaki University). Epitype of the lectotype (designated here):— JAPAN. Kyushu, Kagoshima Prefecture, Kimotsuki-gun, Minamiosumi-machi, Sata, Hetsuka, on fruits of C. daphnoides , 9 October 2000, M. Kakishima (TNS-F-40293), GenBank nos. AB178259, 178260.

Etymology: —The specific epithet refers to the globose shape of the basidiospores.

Galls on the fruits, globose to subglobose, brown, 2–3 times bigger than the sizes of the normal fruits, ca. 10–20 mm in diam. ( Figs 1A, B ); inner tissues consisting of fungal hyphae and deformed plant cells ( Figs 1C, D , 2A ). Hyphae intercellular, hyaline, compact, septate ( Figs 2A, B ); haustoria irregular in shape, observed in deformed host cells ( Figs 2B, C , 3C ). Hymenia formed in peripheral lacunae of galls, yellow to whitish, covered by thick, dark brown pericarps ( Figs 1C, D ). Basidia clavate, hyaline, depressed, hard to observe, gastroid, 9–15 × 5–8 μm ( Figs 2B , 3C ). Paraphyses or sterile hyphae present in the basidial layer, hyaline, thin, long ( Figs 2A , 3C ). Basidiospores globose, subglobose or broadly ellipsoidal, hyaline, 5–10 (av. 7) μm long, aggregated in a mass ( Figs 2D , 3A–C ), wall densely foveolate when mature; producing long branched hyphae with septa when germinated on PDA ( Figs 2E, F ).

Known host and distribution: —On Lauraceae : Cinnamomum daphnoides , Japan (Kagoshima Prefecture).

Comments: —The holotype was not found in the Mycological Herbarium of Faculty of Agriculture, Miyazaki University, nor in any other mycological herbarium in Japan. A lectotype is therefore designated here. The specimen used for sequencing of LSU rDNA is designated here as an epitype of the lectotype.

Four species of Clinoconidium have been previously reported: Cl. bullatum Syd. on species of Apollonias , Ocotea , and Phoebe from Canary Islands, Costa Rica, and Venezuela; Cl. cinnamomi (Syd.) R. Kirschner on Ci. burmanii from China; Cl. farinosum Pat. ex Sacc. on species of Nectandra and Ocotea from Puerto Rico, Brazil, and Argentina; and Cl. sawadae (G. Yamada) R. Kirschner on Ci. camphora L. from Taiwan (Patouillard 1898, Saccardo 1902, Maublanc 1914, Sydow 1926, Hendrichs 2003, Jiang & Kirschner 2016). Sorus structures and gastroid basidia are similar in each species. Clinoconidium globosum differs from the known species by having mainly globose or subglobose basidiospores while the other four species have ellipsoid or oblong, and smaller basidiospores (5–10 μm long versus 6–15 × 5–7 μm for Cl. bullatum , 10–13 × 5–7 μm for Cl. cinnamomi , 8–12 × 6–9 μm for Cl. farinosum , and 9–12 × 5–7 μm for Cl. Sawadae ; after Hendrichs 2003, Jiang & Kirschner 2016).

Jiang & Kirschner (2016) also reported that LSU rDNA sequences from a specimen of this species are phylogenetically different from those of the other four species. However, phylogenetic analyses using other regions of rDNA will be necessary to clarify their phylogenetic relationships and differentiation.

Because the distribution of this species is restricted to a narrow area of Kagoshima Prefecture, Southern Kyushu, Japan, and also this species has been found only on an endemic plant, Cinnamomum daphnoides ( Oba 2006) , it is suggested that Clinoconidium globosum evolved on this host plant.

Figures

FIGURE 1. Galls of Clinoconidium globosum on the fruits of Cinnamomum daphnoides. A. Galls formed on fruits of the tree. Photograph was taken at Hetsuka, Sata, Minamiosumi-machi, Kimotsuki-gun, Kagoshima Prefecture, Kyushu, Japan on 9 October 2000. B. A gall formed on a fruit (G) and a normal fruit (F). C, D. Vertical section of a gall. C. A hymenial layer (HL) formed in a peripheral lacunae of galls with deformed host tissue (PT) inside the fruit. D. A hymenial layer consisting of a basidial layer (BL), basidiospores (B), and pericarp (P). Scale bars: B = 0.5 cm, C = 1 mm, D = 0.2 mm.

FIGURE 2. A, B. A hymenial layer of a gall formed by Clinoconidium globosum stained with lactophenol aniline blue solution.A hyphal mass (HM) among deformed plant cells (PC), haustoria (HA) in host plant cell (PC), basidial layer (BL), basidiospores (B), and sterile hyphae (SH). C. Haustoria (HA) formed in a host plant cell (PC). D. Basidiospores. E. Germination of basidiospores on PDA. F. Hyphae produced from mass of basidiospores on PDA. Scale bars: A, C, F = 10 μm, B, E, D = 5 μm.

FIGURE 3. A, B. Clinoconidium globosum observed by SEM. A. Basidiospores. B. A basidial layer and basidiospores. C. Schematic structure of a hymenial layer of a gall formed by C. globosum. A hyphal mass (HM) among deformed plant cells (PC), haustoria (HA), basidia (BA), basidiospores (B), and sterile hyphae (SH). Scale bars: A= 2 μm, B, C = 10 μm.