Abstract
Two different papaya diseases have been previously reported in Cuba, Bunchy Top Symptom (BTS) associated with a phytoplasma of group 16SrII ‘Candidatus Phytoplasma aurantifolia’ and Papaya Bunchy Top (PBT), associated with a rickettsia. Regarding the regional phytosanitary impact of both diseases for the papaya crop, the present study investigated the occurrence of BTS and PBT in papaya fields in Cuba, and the possible mixed infection of phytoplasma and rickettsia pathogens associated. Papaya plants showing symptoms of BTS or PBT or both, were collected in Las Tunas and Havana provinces from January 2009 to February 2010, and evaluated for phytoplasma and rickettsia by PCR with primers targeting the 16S ribosomal RNA and the rickettsial succinate deshydrogenase (sdhA) genes, respectively. Phytoplasmas and rickettsia were individually detected in 76/86 BTS-symptomatic and 22/22 PBT-symptomatic papaya plants, and simultaneously detected in 5/86 (5.81%) of the BTS-symptomatic and 17/22 (77.27%) of the PBT-symptomatic plants. Conventional and virtual RFLP analyses of the 16S rDNA sequences revealed the presence of phytoplasmas of group 16SrI ‘Candidatus Phytoplasma asteris’ and 16SrII in papaya plants affected by BTS and PBT, and identified two new phytoplasma subgroups, 16SrI-X and 16SrII-N in papayas fields of Las Tunas, which was confirmed by phylogenetic analysis. The partial rickettsia sdhA gene sequences were 100% identical to that of the rickettsia associated with PBT in Puerto Rico. Results confirm that phytoplasmas are consistently associated with both BTS and PBT symptoms, and that mixed infections of phytoplasma and rickettsia pathogens can occur in either BTS or PBT-affected papaya fields, which implies new epidemiological constraints for the disease control.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
