Spread of Erwinia chrysanthemi in Kalanchoë blossfeldiana

Meristems were excised from young and 8-month-old Kalanchoë blossfeldiana naturally-infected with Erwinia chrysanthemi (Echr). From heavily infected plants the bacteria were identified in meristems from the very top of the plant as well as from meristems situated lower on the plant. In other naturally-infected plants Echr was only found at the stem base, depending on how advanced (old) the infection was. Repetition of identification on meristem samples stored in the refrigerator for1 week revealed more positive samples than in the first test. Infection trials showed a quick spread of bacteria from stem base to apex via xylem vessels in some of the inoculated plants. Spread of Echr via capillary mats from inoculated to non-inoculated Kalanchoë plants were found after 5.5 months growth on the capillary mat. The time lapse before transmission may vary with the seasons of the year.