Pleosporales » Dictyosporiaceae » Cheirosporium

Cheirosporium vesiculare

Cheirosporium vesiculare Abdel-Aziz

 

Index Fungorum number: IF 552327; Facesoffungi number: FoF 02493

Etymology: From the Latin adjective vesiculare, in reference to the balloon-shape of the conidial appendages.

Holotype: MFLU 15−1513

 

Saprobic on submerged wood. Sexual morph: Undetermined. Asexual morph: Mycelium immersed in the substrate, hyaline to yellow-brown, 2−4 μm wide, septate. Sporodochia on natural substrata superficial, compact, circular or subglobose, dark-brown, 200 μm to 1 mm diam. Conidiophores macronematous, yellow-brown to brown in color, 0-1 septate, straight or sinuate, branched or unbranched, 5–17 × 3–6 μm. Conidiogenous cells monoblastic, determinate, hyaline to yellow-brown in color, globose, subglobose to ovate in shape, thin-walled, 5–15 μm diam, mostly remain attached to the conidia. Conidia solitary, digitate, non-complanate, clavate to ellipsoidal in frontal view, circular in vertical view, 42–65 × 19–22 μm (x̄ = 55.8 × 20.4 μm, n = 50), yellow-brown to brown, consisting of 71–85 cells, individual cells are rectangular or discoid, 4−7 μm tall, 6−10 μm wide, larger in size toward the middle of the rows than cells in the upper or lower parts of the rows, arranged in 7 compact rows, 6 of which in peripheral positions and one central, each two rows are connected to large basal cell, 9–12 cells per row. Conidial secession is rhexolytic. Conidia are equipped with 2 to 5 large, globose to subglobose, balloon-like with long neck that penetrate between outer rows and connect to the central row. Conidial appendages are deciduous, hyaline, senescent appendages yellow-brown and septate.

 

Culture characters: Conidia germinating on PDA within 24 h and several germ tubes produced from each conidium. Colonies 15–20 mm diam. in two weeks at 23ºC, produce white mycelium with dull yellow reverse. No conidia or sexual stages were recorded.

 

Specimen examined: EGYPT, Sohag, River Nile, on submerged decaying wood, 25 January 2015, F.A. Abdel-Aziz, MFLU 15−1513, holotype; ex-type living culture, MFLUCC 15−0753, MD6006

 

Notes: Phylogenetic analyses of LSU rDNA placed Cheirosporium vesiculare in a monophyletic clade with C. triseriale with low statistical support. Both species form a distal clade in the newly described family, Dictyosporiaceae Boonmee & K.D. Hyde (Boonmee et al. 2016) and sister clade to the sexual species Gregarithecium Kaz. Tanaka & K. Hiray., Pseudocoleophoma Kaz. Tanaka & K. Hiray. and the asexual species Dendryphiella vinosa (Berk. & M. A. Curtis) Reisinger. Cheirosporium species produce macronematous conidiophores and typically rhexolytic secession of conidia. Cheirosporium species differ from Dictyosporium species by having macronematous conidiophores and are phylogentically distant from Dictyosporium sensu stricto clade. C. triseriale differs from C. vesiculare by having sporodochial punctiform conidiomata, complanate conidia, without appendages and conidia with 3 cell rows (Cai et al. 2008). At morphology level, C. vesiculare is reminiscent of Dictyposporium musae Photita and D. tetraploides L. Cai & K.D. Hyde in having hyaline, lateral appendages and overlap conidial dimensions (Photita et al. 2002, Cai et al. 2003a). However, C. vesiculare differs from the two species by having macronematous conidiophores, large hyaline conidiogenous cell, higher numbers of conidial appendages that are larger in size with long neck that penetrate through peripheral cell rows and connect to the central row and senescent appendages become yellow-brown and septate. No molecular data are available for D. musae and D. tetraploides at GenBank.

 

References:

Abdel-Aziz FA. (2016) Two new cheirosporous asexual taxa (Dictyosporiaceae, Pleosporales, Dothideomycetes) from freshwater habitats in Egypt. Mycosphere, 7: .448–457.

Boonmee S, D’souza MJ, Luo Z, Pinruan U, Tanaka K, Su H, Bhat DJ, McKenzie EHC, Jones EBG, Taylor JE, Phillips AJL, Hirayama K, Eungwanichayapant PD, Hyde KD. (2016) Dictyosporiaceae fam. nov. Fungal Diversity 79, online. http://dx.doi.org/10.1007/s13225- 016-0363-z

Cai L, Guo XY, Hyde KD. (2008) Morphological and molecular characterisation of a new anamorphic genus Cheirosporium, from freshwater in China. PersooniaI, 20: 53–58.

Cai L, Zhang K, McKenzie EHC, Hyde KD. (2003) New species of Dictyosporium and Digitodesmium from submerged wood in Yunnan, China. Sydowia, 55: 129–135.

Photita W, Lumyong P, McKenzie EHC, Hyde KD, Lumyong S. (2002) A new Dictyosporium species from Musa acuminata in Thailand. Mycotaxon 82: 415–419.

 
 Fig 1. Cheirosporium vesiculare (holotype). a. Compact sporodochium, on wood, b,c. Conidiophores and conidiogenous cells (arrowed), d,e. Conidia with lateral appendages. Note the teared conidiogenous cell, arrowed in Fig. e, f,g. Magnified apical part of the conidia showing the lateral appendages. Senescent appendages are yellow-brown in color and septate (arrowed in Fig. g), h. Balloon-like appendage with long neck (arrowed), i,j. Conidia with four lateral appendages, conidiogenous cell is arrowed in Fig. i, k,l. Vertical view of the conidia showing the six peripheral rows and one central row and lateral appendages attached to the central row. Scale bars: a = 150 μm, b-l = 10 μm. (Photo grabbed from Abdel-Aziz 2016)

 

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