Ig. Dinesen et Sh. Deboer, EXTRACTION OF CLAVIBACTER-MICHIGANENSIS SUBSP SEPEDONICUS FROM COMPOSITE SAMPLES OF POTATO-TUBERS, American potato journal, 72(2), 1995, pp. 133-142
The presence of Clavibacter michiganensis subsp. sepedonicus was detec
ted by immunofluorescence and ELISA in diluent in which cores from 200
potato tubers had been incubated on a rotary shaker. By this procedur
e the ring rot pathogen was detected in composite samples from natural
ly infected tubers and tuber samples ''spiked'' with infected tissue o
r a pure culture of the pathogen. Populations of saprophytic bacteria
increased about 100-fold in the diluent during 18 h of incubation but
did not interfere with serological detection of C. m. sepedonicus. Som
e of the results suggest that C. m. sepedonicus cells multiply during
incubation of tuber samples. Extraction of ring rot bacteria from pota
to tuber tissue by incubation on a rotary shaker requires little work
and minimizes the amount of plant tissue in the extract compared to th
e standard extraction procedure involving maceration and differential
centrifugation.