Figure 2. Huanglongbing symptoms of the inoculated plants.

Healthy grapefruit rootstocks graft-inoculated with HLB-affected lemon scions treated with ampicillin at a concentration of 1.0 g/L (Amp), gentamicin at a concentration of 100 mg/L (Gm), and a water control (disease control, CK₁); The healthy plants were graft-inoculated with Las-free lemon scions (healthy control, CK₂).