An ultrastructural study was made of the primary leaves of R-type or S-type wheat exposed to helminthosporal toxin,a phytotoxin produced by H.sativum,at three concentrations.A series of subcellular changes were observedsuch as invaginated plasma membranes,swollen cristae,electronlucent matrixand disrupted outer-membranes of mitochondria,dilated and distorted granalamellae and disrupted envelop membranes of chloroplasts,collapsed cell wallsand plasmolysis.The damages on membrane systems of the cells occurred more slightly and later in the R-type cv.than in the S-type cv.The action sites of the ...
