Iew. Obrien, COMPARISON OF MALUS INFECTION BY THE PATHOGEN ERWINIA-AMYLOVORA AND COLONIZATION BY THE SAPROPHYTE ERWINIA-HERBICOLA BY ELECTRON-MICROSCOPY, New Zealand journal of crop and horticultural science, 21(1), 1993, pp. 33-38
Erwinia amylovora infection of either apple stem or leaf tissue result
ed in xylem occlusion by a fibrillar matrix material, determined by Th
iery's thiocarbohydrazide (TCH) test to be the extracellular polysacch
aride from E. amylovora. Plasmolysis of the xylem-parenchyma was also
detected and was most likely a result of a toxin produced by the patho
gen. This plasmolysis resulted in the collapse and death of the cell.
An Erwinia herbicola isolate which had previously expressed inhibitory
effects on E. amylovora was contained at the site of inoculation.