A simple and efficient PCR method for the detection of Agrobacterium tumefaciens in plant tumours

A simple PCR protocol was del-eloped for identifying Agrobacterium as the c ausal agent of the tumours produced bq this bacterium in plant material. Th e sensitivity of this method was compared with that of bacterial isolation using common and selective media with a previous enrichment step. More than 200 samples from tumours of naturally infected and inoculated plants from several hosts including almond, peach x almond hybrids, apricot, rose, toba cco, tomato, raspberry, grapevine and chrysanthemum, were analysed by both methods. PCR was the most efficient method for detecting the bacterial aeti ology of the plant tumours. Agrobacterium tumefaciens was better detected i n crown and root tumours than in aerial tumours with all the methods assaye d in inoculated plants. A comparison between the efficiency of the diagnosi s by analysing pieces from the external and internal part of the tumour sho wed no differences between them.