Characterization of Agrobacterium isolates from naturally occurring plant tumors in Pakistan

Thirty two Agrobacterium cultures were isolated from 24 plant tumor samples , out of them 14 were pathogens. Pathogenicity df the isolates varies from 100% (Peshawar apple isolates) to 25% (Lahore poplar isolates). Biotype II was dominant among all the isolates specially apple ones. Out of the 32 iso lates 16 were grouped in biotype II; whereas, seven and nine were grouped i n biotypes I and III, respectively. Seventeen isolates out of the 32 were o ctopine and nopaline utilizers, six and three were either octopine or nopal ine utilizers, respectively and six were neither octopine nor nopaline util izers.