Observations on cucumber fruit invasion by Pseudomonas lachrymans.
Young cucumber fruits were inoculated with P. lachrymans isolate PL23 at the junction of stems and peduncles. The number of successful infections depended on the cv. and the method of inoculation. The pathogen was found in 54% of the 13 National Pickling and 85% of 13 Greenpak fruits after small needle inoculations; in 30% of 10 of the former after cotton swab inoculation and in 46% of 13 of the latter after triangular file inoculation. Bacteria moved through the peduncle and along the longitudinal axis, primarily in carpellary (vascular) bundles. Radial movement occurred from carpellary bundles through cortex and placenta in proximal parts of fruit. Fruit discolouration and decay were caused by the bacterium and not by secondary soft-rot organisms.<new para>ADDITIONAL ABSTRACT:<new para>Systemic infection was detected in 54% and 85% of fruits of National Pickling and Green Pak respectively, after inoculation with isolate PL23 at stem and peduncle joints using a fine needle.