Absence of Seed-Mediated Transmission of Cucumber Mosaic Virus in Espelette Pepper Crops despite Widespread and Recurrent Epidemics

• Published in: Viruses Vol. 15; no. 11; p. 2159
• Main Authors: Hirsch, Judith, Szadkowski, Marion, Wipf-Scheibel, Catherine, Lepage, Elise, Dumeaux, Paul, Nguyen, Elodie, Verdin, Eric, Moury, Benoît, Rimbaud, Loup
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.10.2023; MDPI
• Subjects: Capsicum annuum; Crop diseases; Crops; Crops, Agricultural; cucumber mosaic virus; Cucumovirus - genetics; Cultivars; Cytomegalovirus; Cytomegalovirus Infections; Disease transmission; Diseases and pests; Distribution; Environmental aspects; Epidemics; Epidemiology; Experiments; Flowers & plants; France - epidemiology; Fruits; Greenhouses; Inoculum; Leaves; Life Sciences; Microbiology and Parasitology; pepper; Peppers; Phytopathology and phytopharmacy; Plant viruses; Polymerase chain reaction; Reverse transcription; seed transmission; Seedlings; Seeds; Tourism; Vegetal Biology; vertical transmission; Virology; Virus diseases of plants; Virus research; France; pepper; vertical transmission; Capsicum annuum; seed transmission; cucumber mosaic virus
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v15112159

In the past decade, severe epidemics of cucumber mosaic virus (CMV) have caused significant damage to Espelette pepper crops. This virus threatens the production of Espelette pepper, which plays a significant role in the local economy and touristic attractiveness of the French Basque Country, located in southwestern France. In 2021 and 2022, CMV was detected via double-antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISAs) in Gorria pepper seed lots harvested from naturally infected fields scattered throughout the entire Espelette pepper production area. These seed lots were used in greenhouse grow-out tests to determine whether CMV could be transmitted to seedlings from contaminated seeds, using visual symptom assessment, DAS-ELISAs, and reverse transcription-polymerase chain reaction (RT-PCR). Despite the widespread occurrence of CMV in seeds of field samples, the grow-out experiments on a total of over 5000 seedlings yielded no evidence of seed transmission of local CMV isolates in Gorria pepper. Therefore, rather than seeds from infected pepper plants, sources of CMV inoculum in Espelette are more likely to be alternative hosts present in and around pepper fields that can allow for the survival of CMV during the off-season. These results have important epidemiological implications and will guide the choice of effective measures to control current epidemics.