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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Disease and Pest Management Research Unit » Research » Publications at this Location » Publication #399691
Research Project: Disease Management in Small Fruit and Nursery Crops Based on Knowledge of Pathogen Diversity, Biology, and Environmental Effects

Location: Horticultural Crops Disease and Pest Management Research Unit

Title: Papaya ‘sticky’ disease caused by virus ‘couples’: a challenge for disease detection and management

Author
item QUITO-AVILA, DIEGO - Centro De Investigaciones Biotecnologicas Del Ecuador
item REYES-PROAÑO, EDISON - Centro De Investigaciones Biotecnologicas Del Ecuador
item CAÑADA, GABRIELA - Centro De Investigaciones Biotecnologicas Del Ecuador
item CORNEJO-FRANCO, FRANCO - Centro De Investigaciones Biotecnologicas Del Ecuador
item ALVAREZ-QUINTO, ROBERT - Oregon State University
item MOREIRA, LISELA - Costa Rica Institution
item Grinstead, Sam
item Mollov, Dimitre
item KARASEV, ALEXANDER - University Of Idaho

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2022
Publication Date: 6/1/2023
Citation: Quito-Avila, D., Reyes-Proaño, E., Cañada, G., Cornejo-Franco, F., Alvarez-Quinto, R., Moreira, L., Grinstead, S.C., Mollov, D.S., Karasev, A. 2023. Papaya ‘sticky’ disease caused by virus ‘couples’: a challenge for disease detection and management. Plant Disease. 107(6):1649-1663. https://doi.org/10.1094/PDIS-11-22-2565-FE.
DOI: https://doi.org/10.1094/PDIS-11-22-2565-FE

Interpretive Summary: Papaya is a tropical fruit consumed worldwide. Papaya is hindered by many viral diseases and among them is papaya sticky disease (PSD). PSD is characterized by sap leaking from the fruit which makes it unmarketable. PSD was thought to be caused by the combination of two viruses. In this research we explored the correlation of PSD and the viruses present in infected trees. Our results suggest that another virus also attributes to PSD. With these findings we described all viruses attributing to PSD. Additionally, we described detection methods for all PSD viruses which could be utilized in papaya commercial production and used in PSD management strategies.

Technical Abstract: Papaya sticky disease (PSD) is a major virus disorder of papaya (Carica papaya). The disease is characterized by fruit damage caused by the oxidation of spontaneously exudated latex. In Brazil, PSD is caused by the co-infection of two viruses, papaya meleira virus (PMeV), a toti-like virus and papaya meleira virus-2 (PMeV-2), an umbra-like virus. The disorder has also been reported in Mexico and more recently in Australia, but the presence of both PMeV and PMeV-2 in symptomatic plants have only been documented in Brazil. In 2021, two-year-old papaya plants (cv. Passion Red) exhibiting PSD-like symptoms were observed in Santa Elena province, Ecuador. RT-PCR tests of leaf tissue and fruit latex from symptomatic plants failed to detect PMeV. However, papaya virus Q (PpVQ), an umbra-like virus related to PMeV-2, was found in the samples. High-throughput sequencing of the total RNA from a latex sample revealed the presence of a ~ 9 kbp-long virus sequence sharing 56% identity at the nucleotide level to the PMeV from Brazil. RT-PCR using specific primers revealed the new virus in 100% of all PSD-symptomatic plants, but also in asymptomatic ones. This review discusses the history, epidemiology and the genomic features of newly discovered viruses involved in PSD. The importance of implementing proper diagnostic approaches for PSD is highlighted.