Multiplication and Translocation ofXylella fastidiosain Petioles and Stems of Grapevine Resistant, Tolerant, and Susceptible to Pierce's Disease

(...) Populations of the bacterium increased rapidly in petioles of French Colombard but increased gradually in Carlos and Noble. Maximum populations were attained faster in French Colombard than in Carlos and Noble. X. fastidiosa rapidly colonized leaf veins of all cultivars. (...) Both strains were translocated throughout French Colombard. The FC strain was reisolated at 50 cm in Carlos and 10 cm in Noble, 8 wk after 5-wk-old plants were inoculated. The C strain was not detected in Carlos or Noble. The FC strain was reisolated throughout Carlos and Noble, 8 wk after 7-wk-old plants were inoculated. The C strain was reisolated no higher than 10 cm above the inoculation point in Carlos and Noble