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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #322770
Title: First report of Potato virus V and Peru tomato mosaic virus on tamarillo (Solanum betaceum) orchards of Ecuador

Author
item INSUASTI, M - National Institute For Agricultural Research (INIAP)
item OCHOA, J - National Institute For Agricultural Research (INIAP)
item Martin, Robert
item ALVAREZ, R - Centro De Investigaciones Biotecnologicas Del Ecuador
item QUITO-AVILA, D - Centro De Investigaciones Biotecnologicas Del Ecuador

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2015
Publication Date: 3/23/2016
Citation: Insuasti, M., Ochoa, J., Martin, R.R., Alvarez, R.A., Quito-Avila, D.F. 2016. First report of Potato virus V and Peru tomato mosaic virus on tamarillo (Solanum betaceum) orchards of Ecuador. Plant Disease. 100(4):868-869. doi: 10.1094/PDIS-09-15-1063-PDN.

Interpretive Summary: In Ecuador, tamarillo (Solanum betaceum) represents an important cash crop for hundreds of small farmers. In 2013 efforts were initiated to determine the cause of severe virus-like symptoms that included mosaic, mottling and leaf deformation. Results from 400 sequenced clones from three separate dsRNA preparations from symptomatic plants, revealed the presence of three potyviruses: Potato virus Y (PVY), Potato virus V (PVV) and Peru tomato mosaic virus (PTMV), and the polerovirus Potato leaf roll virus (PLRV). Primers for detection of these four viruses were developed based on the sequences obtained. The incidence of PVY, PVV, PTMV and PLRV was estimated by testing of 200 tamarillo plants with different symptom severity including asymptomatic plants sampled in orchards. Among the potyviruses, PVY was the most common with 64% of plants infected, whereas PVV and PTV were found in 8% and 10%, respectively. PLRV was detected in 30% of symptomatic plants. Mixed infections among potyviruses were present but less frequent (4 – 8%) compared to plants co-infected with PVY and PLRV (22%). The PVY was the necrotic strain of PVY. Plants were also tested for Cucumber mosaic virus and Tamarillo mosaic virus since they have been reported in tamarillo elsewhere, these two viruses were not detected in the survey in Ecuador.

Technical Abstract: In Ecuador, tamarillo (Solanum betaceum) represents an important cash crop for hundreds of small farmers. In 2013, leaves from tamarillo plants showing severe virus-like symptoms (mosaic, mottling and leaf deformation) were collected from old orchards in Pichincha and Tungurahua. Double-stranded RNA (dsRNA) was extracted and used as initial template to screen for RNA viruses by shotgun cloning. Results from 400 sequenced clones from three separate dsRNA preparations, revealed the presence of three potyviruses: Potato virus Y (PVY), Potato virus V (PVV) and Peru tomato mosaic virus (PTMV), and the polerovirus Potato leaf roll virus (PLRV). Detection primers were designed for each virus. None of the viruses were detected from asymptomatic plants. The incidence of PVY, PVV, PTMV and PLRV was estimated by RT-PCR testing of 200 tamarillo plants with different symptom severity including asymptomatic plants sampled in orchards from the same provinces. Among the potyviruses, PVY was the most common with 64% of plants infected, whereas PVV and PTV were found in 8% and 10%, respectively. PLRV was detected in 30% of symptomatic plants. Mixed infections among potyviruses were present but less frequent (4 – 8%) compared to plants co-infected with PVY and PLRV (22%). Based on recent reports on tamarillo viruses in other countries, samples were also tested for Cucumber mosaic virus and Tamarillo mosaic virus by RT-PCR. All plants tested negative for both viruses. PVY-singly infected plants were positive for PVYN when tested using PVY serotype-specific ELISA kits (AGDIA).