In Vitro Tests of Resistance to Soft Rot Erwiniae on Potato Tubers

Potato breeding goes back to several decades in the Research Center of the University of Debrecen. Our work is based of evaluation of wild Solanum species carrying resistance or tolerance to Erwinia carotovora and Erwinia chrysanthemi. These bacteria infect potatoes in almost every region in the temperate, semitropical and tropical zone of the world as well as in Hungary. Cultivars in commercial production have different levels of sensitivity, but no cultivar being resistant to the soft rot disease. In the present study tubers of 13 potato genotypes were used. Discs of tubers were inoculated with the bacterial suspension contained 10(8) CFU and incubated at 26 degrees C for 24-26 h. After the decayed tissues were washed down and the weight of the healthy tissues was measured. The degree of resistance was determined by the ratio of the healthy tissue. According to our results we could conclude that the method used are suitable for a fast screening of breeding materials and cultivars for evaluate their resistance to different Erwinia species and strains.