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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #272131
Title: First report of turnip mosaic virus in tomatillo (Physalis philadelphica) in California

Author
item Liu, Hsing Yeh
item KOIKE, STEVEN - University Of California - Cooperative Extension Service
item XU, DONGLIN - South China Agricultural University
item Li, Ruhui

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2011
Publication Date: 2/1/2012
Citation: Liu, H., Koike, S.T., Xu, D., Li, R. 2012. First report of turnip mosaic virus in tomatillo (Physalis philadelphica) in California. Plant Disease. 96(2):296.

Interpretive Summary: Tomatillo (Physalis philadelphica, Solanaceae) is an important vegetable in Mexican cuisine. It is of Mesoamerica origin and now is grown widely in the Western Hemisphere. In 2011, commercially grown tomatillo plants in San Benito Counties, California exhibited severe stunting with foliage showing mosaic symptoms and leaf distortion. The fruits on infected plants were mottled and unmarketable. Flexuous filamentous-shaped virus particles were observed from sap of the symptomatic plants under a transmission electron microscope. Sap from the diseased plant reacted positively in an immunostrip assay for potyvirus (Agdia Inc., Elkhart, USA), indicating a potyvirus was associated with the disease. The causal agent was mechanically transmitted and also transmitted by the green peach aphid (Myzus persicae) in a non-persistent manner. To further identify the causal agent, total nucleic acids were extracted and tested by reverse transcription (RT)-PCR. An amplicon of approximately 700 bp from the diseased tomatillo was cloned and sequenced. The sequence showed that the virus was 93.6% identical at the nucleotide sequence and 100% identical at the amino acid sequence with Turnip mosaic virus (TuMV). Our results indicated that the disease was caused by TuMV. To our knowledge, this is the first report of TuMV in tomatillo. Since TuMV has a wide host range and is readily transmitted by green peach aphids, TuMV could be a new threat to tomatillo production in California.

Technical Abstract: Tomatillo (Physalis philadelphica, Solanaceae) is an important vegetable in Mexican cuisine. It is of Mesoamerica origin and now is grown widely in the Western Hemisphere. In 2011, commercially grown tomatillo plants in San Benito Counties, California exhibited severe stunting with foliage showing mosaic symptoms and leaf distortion. The fruits on infected plants were mottled and unmarketable. Flexuous filamentous-shaped virus particles of 800-850 nm long and 11-12 nm wide were observed from sap of the symptomatic plants under a transmission electron microscope. Sap from the diseased plant reacted positively in an immunostrip assay for potyvirus (Agdia Inc., Elkhart, USA), indicating a potyvirus was associated with the disease. The causal agent was mechanically transmitted from the diseased field plants to greenhouse tomatillo plants and induced identical symptoms. The causal agent was also transmitted to Chenopodium quinoa and C. murale (chlorotic local lesions), and Nicotiana clevelandii, N. tabacum, and Physalis wrightii (systemic symptoms). The disease was transmitted to tomatillo plants by the green peach aphid (Myzus persicae) in a non-persistent manner. To further identify the causal agent, total nucleic acids were extracted using a CTAB method (2) and tested by reverse transcription (RT)-PCR using potyvirus degenerate primers CIFor and CIRev (1). An amplicon of approximately 700 bp from the diseased tomatillo was cloned and sequenced. Analysis of the 631-bp partial CI sequence (GenBank Accession No. JN601884) showed that the virus was 93.6% identical at the nucleotide sequence and 100% identical at the amino acid sequence with Turnip mosaic virus (TuMV) (GenBank Accession No. D10927). Our results indicated that the disease was caused by TuMV. To our knowledge, this is the first report of TuMV in tomatillo. Since TuMV has a wide host range and is readily transmitted by green peach aphids, TuMV could be a new threat to tomatillo production in California.