Ephelis spp.

Description

Stromata enclosing the entire inflorescence or individual spikelets depending on the host, cylindrical, straight to slightly curved, tapering to a point, ranging from 10-18 x 2-3 mm to 90-150 x 3-7 mm dependant on the host, at first white-cream then becoming darker; sometimes an evanescent, thin, white mycelial mat may also cover the expanding leaves at the apices of Ephelis-infected tillers.

Conidiomata on stromata circular-irregular, grey at maturity, surface slightly concave, margins raised and dark grey, variously described as acervuli or sporodochia.

Conidia of one type

  • conidia formed on short conidiophores in conidiomata and on epiphylous mats, acicular, 12-26 x 1-2 µm, hyaline, aseptate.
Hosts
   
Host family: Poaceae
   
Host species: Botrhiochloa sp.
Brachiaria humidicola
Brachiaria mutica
Brachiaria ruziziensis
Cymbopogon refractus
Digitaria ciliaris
Digitaria erianthi subsp. pentzii
Digitaria eriantha subsp. eriantha
Digitaria violascens
Digitaria sp.
Melinis repens
Paspalidium criniforme
Paspalum scrobiculatum
Pennisetum alopecuroides
Pennisetum compressum
Poa labillardierei
Setaria sphacelata
Sorghastrum nutans
Sorghum halepense
Sorghum leiocladum
Sorghum verticilliflorum
Themeda triandra

Distribution

NSW, NT, QLD

Comments

Ephelis spp. are recognised as the anamorphs of Balansia, Myriogenospora and Nigrocornus (Diehl, 1950; Rykard et al., 1984; Ryley 2003) and more recently as the anamorph of Neoclaviceps (Sullivan et al., 2001) although the latter association is doubtful. There is considerable diversity in the morphology of the conidiomata of Ephelis – at one extreme are discrete and cupulate-patellate structures, variously referred to as sporodochia and acervuli, and at the other extreme is an effuse layer of conidiophores which covers the surface of the stroma or host tissue (Christensen et al. 2000; Ryley, 2003). In all cases, acicular aseptate conidia develop at the apices of sympodially proliferating conidiogenous cells (Rykard et al., 1984; Ryley, 2003). The sexual states of Balansia and related genera usually, but not always, develop after the Ephelis state on conidiostromata; by contrast the asexual and sexual states of Nigricornus scleroticus are spatially- and temporally- separated.

Highslide JS
Ephelis sp. on Cymbopogon sp.
Highslide JS
Ephelis sp. on Cymbopogon sp.
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Ephelis sp. on Cymbopogon sp.
Highslide JS
Ephelis sp. on Cymbopogon sp.
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Ephelis sp. on Cymbopogon sp.
Highslide JS
Ephelis sp. on Sarga sp.
Highslide JS
Ephelis sp. on Sarga sp.
Highslide JS
Ephelis sp. on Cymbopogon refractus - BRIP 27595. Scale bar = 1 cm.
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Ephelis sp. on Cymbopogon refractus - BRIP 27595. Scale bar = 3 mm.
Highslide JS
Ephelis sp. on Sorghum leiocladum - BRIP 45135. Scale bar = 5 mm.
Highslide JS
Ephelis sp. on Sorghum leiocladum - BRIP 45135.
Scale bar = 2 mm.
Highslide JS
Ephelis sp. on Sorghum leiocladum - BRIP 45135.
Scale bar = 20 µm.
Highslide JS
Ephelis sp. on Sorghum leiocladum - BRIP 45135.
Scale bar = 20 µm.
Highslide JS
Ephelis sp. on Sorghum leiocladum - BRIP 45135.
Scale bar = 20 µm.