Open AccessBacterial Leaf Spot of Lettuce: Relationship of Temperature to Infection and Potential Host Range of Xanthomonas campestris pv. vitians
Author(s) -
P. E. Robinson,
Jeffrey B. Jones,
Ken Pernezny
Publication year - 2006
Publication title -
plant disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.663
H-Index - 108
eISSN - 1943-7692
pISSN - 0191-2917
DOI - 10.1094/pd-90-0465
Subject(s) - pepper , biology , xanthomonas campestris , infectivity , inoculation , population , host (biology) , horticulture , botany , chenopodium , incubation period , pathogen , microbiology and biotechnology , bacteria , incubation , virology , ecology , biochemistry , virus , genetics , demography , sociology , weed
Epidemiological aspects, including optimum temperature for infection and host range of Xanthomonas campestris pv. vitians, causal organism of bacterial leaf spot (BLS) of lettuce, were investigated. The optimum temperature for infection was determined to be 22.7°C based on growth chamber studies. Internal populations were monitored over time in lettuce, tomato, pepper, parsley, cilantro, and beet. Each plant species was infiltrated with the bacterium at 10 5 CFU/ml. Highest populations developed in lettuce (10 8 CFU/cm 2 ) followed by pepper with 10 6 CFU/cm 2 , whereas the other plant species harbored much lower populations (10 5 to 10 3 CFU/cm 2 ). Infectivity titration endpoints were similar in pepper and lettuce (10 3 to 10 4 CFU/ml). For other plant species tested, infectivity titration endpoints were 10 6 to 10 7 CFU/ml. Electrolyte leakage data and corresponding internal population data support the conclusion that fresh-market tomato is not a host of X. campestris pv. vitians but, instead, interacts in an incompatible response. Electrolyte leakage from cells of tomato plants inoculated with X. campestris pv. vitians or a pepper strain of X. axonopodis pv. vesicatoria peaked at 48 h, suggesting that tomato is not a host for the BLS pathogen. Both electrolyte leakage and population dynamics results point to pepper as a potential host of X. campestris pv. vitians.