Department of Crop Protection, Faculty of Agriculture, University of Khartoum,
Shumbat, Sudan
ABSTRACT
Isolation of soft rot bacteria was made from potato tubers and soil samples collected from
different districts of potato production. The bacterial isolates induced hypersensitive reactions on tobacco leaves and produced typical blackleg and soft-rot symptoms on potato plants and tubers, respectively. A wide range of fruits and vegetables were also found susceptible to the isolates.
Morphological, biochemical and physiological characterization of the isolates proved that
they all belong to the Erwinia carotovora group. All are gram negative, motile, non-spore forming and capable of producing various chemical compounds and enzymes. Although all were able to produce acid and gas from the tested carbohydrates, only two of them utilized maltose and glycerine.