Isolation of two toxins produced by Pyrenophora teres and their significance in disease development of net-spot blotch of barley

摘要: Abstract Two toxins, designated toxin A and B, were isolated from a cell-free, sterile culture filtrate of Pyrenophora teres by means extraction, gel filtration ion-exchange chromatography. Without the presence pathogen each purified toxins incites most important symptoms disease when introduced into healthy barley leaves. Toxin is potent, producing in concentrations as low 25 μg/ml. The virulent isolates produce highest concentration vitro . good, although not complete, correlation was found between host range that toxins. Both infected but results indicate P. produces two which may be involved syndrome net-spot blotch barley. do seem to determine pathogenicity contribute virulence individual isolates.