SPREAD OF ERWINIA-CHRYSANTHEMI IN KALANCHOE-BLOSSFELDIANA

Meristems were excised from young and 8-month-old Kalanchoa 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 for 1 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 mars from inoculated to non-inoculated Kalanchoe 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.