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Table 1 Effect of romaine lettuce susceptibility to downy mildew on the multiplication of EcO157 in leaf tissue in three replicate experiments

From: Downy mildew disease promotes the colonization of romaine lettuce by Escherichia coli O157:H7 and Salmonella enterica

  Log-10 increase in EcO157 population size on leaf tissue of two lettuce accessions a
  Experiment 1 b Experiment 2 Experiment 3
Tissue RH TT   RH TT   RH TT  
Healthy 1.1 A 1.2 A (0.301)c 0.9 A 0.7 A (0.420) 0.3 A 0.5 A (0.552)
Chlorotic 1.1 A 2.5 B (0.012) 2.1 B 1.8 B (0.124) 1.2 B 1.3 B (0.877)
Necrotic 2.8 B 3.2 B (0.140) 2.4 B 3.1 C (0.002) 2.3 C 3.1 C (<0.0001)
  0.0006d 0.0015   <0.0001 <0.0001   <0.0001 <0.0001  
  1. aRomaine lettuce accessions tested were RH08-0464 (RH) and Triple Threat (TT) with low and high susceptibility to downy mildew, respectively.
  2. bIncrease in EcO157 population size on the two lettuce accessions was assessed at 18, 20 and 20 h post-inoculation in replicate experiment 1, 2, and 3, respectively.
  3. cValues in parenthesis are P values resulting from the t-test between RH and TT for the type of tissue within the experiment.
  4. dValues at the bottom of each column are P values resulting from ANOVA on the different types of tissue within plant accession and experiment. Different letters within column indicate means that are significantly different at P < 0.05. Significant differences were determined using the Tukey- Kramer procedure for multiple comparisons.