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 Sclerotinia spermophila
BiostatusPresent in region - Exotic
Images (click to enlarge)
Caption: Figs. 1-8. Sclerotninia spermophila. Fig. 1. Healthy seed of white clover (New Zealand).
Fig. 2. Seed of white clover (New Zealand) infected by S. spermophila
Fig. 3. The same, with developig sclerotia, after being kept damp. |
Article: Noble, M. (1948). Seed-borne diseases of clover. Transactions of the British Mycological Society 30: 84-91.
Description: Sclerotia black, irregular in shape, often spherical, 0.5-1.5 mm. diam. Apothecia arising
singly or in small groups from sclerotia, cup-shaped, becoming flat. Disk 0.5-1.5 mm. diam.,
cinnamon-brown (Ridgway). Stipe of the same colour as the disk at the top but darkening to
black at the base, hairy, 1-9 mm. long, 0.5 mm. diam. Asci cylindrical 153-215 x 11-18 µ,
average of fifty, 179 x 14 µ, apex slightly thickened and staining blue with iodine, spores
occupying half the length. Ascospores 8, generally uniseriate, ellipsoidal, hyaline,
continuous, 12-19 x 7-12 (13) µ, average of 100, 15 x 9 µ. Paraphyses branched at base,
slightly thickened terminally, of the same length as the asci. Macroconidial stage of the
Botrytis type, conidiophores usually arising singly bearing the conidia in small groups on
short sterigmata. Conidia hyaline, oval to long oval, (7) 10-18 x (4) 6-10 µ, average of 100,
12.4 x 7.5 µ. Microconidia small, globose, approx. 3 µ diam., hyaline, with one guttule,
arising exogenously on penicilloid conidiophores.
Habitat: in seeds of white clover, particularly of New Zealand origin.
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