Rhynchosporoside, a host-selective toxin produced by Rhynchosporium secalis, the causal agent of scald disease of barley.
Rhynchosporoside, a phytotoxic compound, has been isolated from cultures of Rhynchosporium secalis, the causal agent of scald disease of barley. The toxin is a cello-bioside of 1,2-propanediol. The compound may play some role in symptom expression because it was isolated from diseased plants in concentrations similar to those that could cause symptoms in toxin-treated plants. The toxin causes leaf tip and marginal necrosis and subsequent chlorosis of the entire leaf. The toxin affects only certain cultivars and lines of barley and rye; however, it also affects certain nonhosts of R. secalis. The genetic factor controlling host resistance to the fungus is not identical to that controlling insensitivity to the toxin.
Department of Plant Pathology, Montana State University, Bozeman, Montana 59717.
P
P
Auriol
G
G
Strobel
J P
JP
Beltran
G
G
Gray