ASSOCIATION OF CANDIDATUS LIBERIBACTER SOLANACEARUM WITH THE DECLINE OF TOMATO SOLANUM LYCOPERSICUM L
R.I. Rojas-Martínez, E. Zavaleta-Mejía, D.L. Ochoa-Martínez, I. Alanís-Martínez, F. García-Tapia
Among the problems affecting the tomato crop (Solanum lycopersicum L.) are those induced by pests and diseases that have caused a reduction in the cultivated area. Since 1998, the insect Bactericera cockerelli has caused phytosanitary problems in many solanaceous crops, such as tomatillo (Physalis ixocarpa), potato (Solanum tuberosum), eggplant (S. melongena), chilli (Capsicun annum) and tomato (S. lycopersicum). The insect is present in all tomato-producing areas of Mexico. In recent years in the United States, a new disease known as "Tomato decline" has been detected in tomato; the symptoms include chlorosis of apical shoots, lanceolate leaflets with epinasty and margins with purple coloration, necrosis and abortion of flowers, mature leaves brittle and rolled up, reduced internodes and reduced growth. In Mexico, a similar disease is present in tomatoes and it has been postulated that B. cockerelli is the vector of a phytoplasma inducing such symptoms. Some evidence suggests that the decline could be induced by Candidatus Liberibacter solanacearum. Therefore, the aim of this study was to determine if the bacterium is associated with the decline of tomato. The positive detection of Candidatus Liberibacter solanacearum by qPCR in grafted tomato plants, or those exposed to B. cockerelli carrying the bacterium and its presence in the phloem of infected plants, confirmed that the bacterium is associated with this disease.