Molecular epidemiology and integrated management of Huanglongbing (asiaticus and americanus) in the State of São Paulo

Abstract

This research project has ten subprojects. Its joint analysis will allow a better understanding .f the structure and behavior of the Huanglongbing path system in São Paulo, a sine qua non condition for the definition of a more rational disease management. The proposed subprojects are: 1) development, evaluation, and application of real time PCR for diagnosis and detection of Ca. Liberibacter asiaticus and Ca. L. americanus in plants and insect vectors and in the study of the vector (Diaphorina citri) infectivity; 2) Spatial and temporal molecular epidemiology of HLB (asiaticus and americanus) in greenhouse conditions considering two different inoculums sources; 3) spatial and temporal analysis of HLB epidemics in commercial orchards; 4) determination of acquisition and inoculation periods of Ca. Liberibacter americanus e Ca. L. asiaticus for Diaphorina citri; 5) determination of incubation and latent periods of HLB (asiaticus and americanus) after transmission by Diaphorina citri; 6) effect of temperature and geographic region on the progress of HLB (asiaticus and americanus); 7) geographic distribution of Ca. Liberibacter americanus e Ca. L. asiaticus in the state of São Paulo; 8) progress of colonization of HLB (asiaticus and americanus) in different citrus varieties with different ages; 9) determination of natural infectivity of the vector (Diaphorina citri) in orchards with different HLB (asiaticus and americanus) incidences; 10) strategies of control of HLB in commercial orchards based on more favorable times for elimination of symptomatic plants and vector control. The core of the project is the HLB epidemiology, always considering both, Ca. L. americanus e Ca. L. asiaticus. All subprojects will be assessed through visual inspection and molecular methods. These will be applied for the first time in the epidemiological study of HLB. The final objective is to control the disease in a more rational way. Many of the proposed studies are original for Ca. L. asiaticus. All of them are original for Ca. L. americanus, the HLB form most disseminated in São Paulo. (AU)