Detection of phytoplasma and potyvirus pathogens in papaya (Carica papaya L.) affected with ‘Bunchy Top Symptom’ (BTS) in eastern Cuba

Symptoms associated with the papaya ringspot virus (PRSV) were observed in papaya fields from eastern Cuba affected with the ‘Bunchy Top Symptom’ (BTS) phytoplasma. Total DNA and RNA extracted from symptomatic and asymptomatic papayas, were respectively subjected to nested PCR by using phytoplasma 16S rDNA primers, and to RT-PCR with generic coat-protein potyvirus primers. Nested PCR products were obtained for 45/47 of BTS-symptomatic papayas, as well as RT-PCR amplicons for 36/47. No PCR products were observed for asymptomatic plants. The BTS phytoplasma was identified as a member of group 16SrII, “Candidatus Phytoplasma aurantifolia”, while the potyvirus showed a 94% of CP identity with that of PRSV from Ivory Coast. Both typical phytoplasma pleomorphic bodies and potyvirus-like particles were observed in symptomatic papayas examined. Results suggest that the BTS phytoplasma and PRSV coexist in BTS-affected papayas, which must be considered for further management strategies, including investigations of further epidemiological implications.