Rickettsia-related bacteria associated with papaya plants showing bunchy top disease in Cuba

Papaya bunchy top (PBT) disease has been associated with Rickettsia-related proteobacterium. To study the occurrence of this proteobacterium in Cuba, during 2012, we collected 264 samples from asymptomatic and symptomatic papaya trees in three regions of Cuba. Symptomatic tissue evaluated by transmission electron microscopy revealed Rickettsia-like morphology. PCR using rickettsial sdhA-specific primers amplified a single band with expected size from 95 % of symptomatic plants. Phylogeny confirmed the presence of Rickettsia-related proteobacterium in plant showing PBT disease. This work confirms Rickettsia-related proteobacterium is a generalized pathogen in papaya plant affected by bunchy top disease in Cuba.