Search on : Taxa descriptions

 


   
Literature:
 
Page number:251 
Remarks (internal):The link between Schizothyrium pomi and Zygophiala jamaicensis was established by Durbin et al (1953), who inoculated apple fruit with ascospores, which resulted in both the teleomorph and anamorph states developing. This relationship has been observed numerous times subsequently and has not yet been questioned. However, when Martyn (1945) described Z. jamaicensis from banana leaves collected in Jamaica, conidiophores were observed to be 16-24 x 4-5 µm and conidia 15-18 x 4-5 µm. In the present study we found that neither of these measurements overlapped with those of the Zygophiala anamorph of S. pomi. Although the relationship between Schizothyrium and Zygophiala is correct, our data suggest that the anamorph of S. pomi is an unnamed species of Zygophiala and not Z. jamaicensis.

 
Description type:Non-original description 
Description:Schizothyrium pomi (Mont. & Fr.) Von Arx, Proc. K. Ned. Akad. Wet., Ser. C, Biol. Med. Sci. 62:336. 1959. Figs. 3, 4
?Labrella pomi Mont. (Fr. in litt.), Ann. Sci. Nat., Sér. 2, Bot. 1:347. 1834.
Anamorph.. Zygophiala sp. (non Z. jamaicensis E.W. Mason).
Ascomata black, shiny, dimidiate, in random clusters, but frequently in circles, superficial on leaves, stems or fruit, appressed to the cuticle, 150-375 µm diam, 30-50 µm high, with irregular margins; upper layer consisting of interwoven mycelium, forming 2-4 layers of thick-walled, brown, pseudoparenchymatal cells, 4-8 µm thick; ostiole central, but upper layer splitting at maturity via irregular ruptures from the elevated center; ascomata situated on a thin, hyaline, basal stroma. Hamathecium hyaline, consisting of branched, septate, pseudoparaphysoid-like filaments, 3-5 µm wide. Asci bitunicate, 8-spored, ovoid to subglobose or ellipsoid to clavate, apical chamber present but inconspicuous at maturity, 20-45 x 8-16 µm; formed in a single layer in the hamathecial tissue. Ascospores hyaline, guttulate, thick-walled, medianly 1-septate, constricted at septum, fusoid-ellipsoidal, widest in the middle of the apical cell, which is acutely rounded, while the lower cell is subobtusely rounded, (10-)12-13(-14) x (3-)3.5-4(-5) µm. Ascospores germinating after 24 h on MEA, becoming brown and verruculose, with a visible mucoid sheath surrounding the spore on the agar surface, slightly or not constricted at the septum, 4-5 µm wide, not distorting, germinating from both ends, with 2-3 germ tubes; cultures are homothallic.
Conidiophores arising from superficial hyphae, 2-3 µm wide, erect, scattered, 3-4-septate, subcylindrical, rarely straight, mostly flexuous, consisting of a hyaline to subhyaline supporting cell that gives rise to a smooth, dark brown stipe, 25-35 x 7-8 µm (from basal septum to below phialide), terminating in a finely verruculose, medium brown apical cell, 6-7 x 6-7 µm, that gives rise to two (rarely three) medium brown, finely verruculose, doliiform to ellipsoid or subcylindrical, polyblastic conidiogenous cells, 8-12 x 6-7 µm; scars prominent, apical, darkened, thickened, somewhat refractive, with 1(-2) per conidiogenous cell, 2 µm wide. Conidia solitary, fusiform to obclavate, hyaline, smooth and thick-walled, transversely 1(-7)-septate, prominently constricted at septa, (20-)22-25(-30) x 5-7(-8) µm if 1-septate but up to 110 µm long if 7-septate; apex subobtuse, base subtruncate, with a darkened, thickened hilum, 2 µm wide.
 
Taxon name: