ABSTRACT
Isolation of bacteria from infected disease plant material is an important step in the determination of the cause of the plant disease, and further, to prove Robert Koch’s postulate for confirmation of the cause of the disease as bacteria. Many plant pathogenic bacteria can be isolated from soil, too, as infected leaves and plant debris fall on the ground, are buried in the soil, and the decomposing infected material releases the bacteria in the soil of the plant canopy. Such soils can be used for the isolation of disease, causing bacterium when the symptoms are not available on the young growing leaves, for example, oily spot disease of pomegranate or bacterial wilt of solanaceous crops Bacterial plant pathogens can also be isolated from field water and irrigation channel waters. The bacterial plant pathogens which are seedborne or transmitted through seed can be isolated from seed material.
