Zinder and Lederhcrg (1952) discovered transduction in Salmonella typhimurum. Phage mediated DNA transfer is called transduction.
Transduction is of two types:
1. Generalized transduction and
2. Specialized or restricted transduction.
1. Generalized transduction: The ability of a bacteriophage to carryr genetic material of any region of bacterial DNA is called generalised transduction.
2. Specialized or restricted transduction: The ability of the bacteriophage to carry only a specific region of the bacterial DNA is called specialized or restricted transduction.