New weed hosts for Cucumber green mottle mosaic virus in wild Mediterranean vegetation

Abstract

The Tobamovirus Cucumber green mottle mosaic virus (CGMMV) is considered a major risk for cucurbit crop production. In 2013, an outbreak of CGMMV in watermelon fields occurred in Israel causing severe crop damage. This event raised concern regarding the virus preservation potential in weeds within and surrounding cultivated cucurbit crops. Out of 11 surveyed weed species, six were ELISA-positive for CGMMV, although they were asymptomatic: Moluccella laevis, Withania somnifera, Amaranthus graecizans, A. muricatus, Ecballium elaterium and Chrozophora tinctoria. The presence of CGMMV in the weed species was verified by RT-PCR analysis and by bioassay to healthy melon, cucumber and Nicotiana benthamiana plants and to non-infected weed species. These results add species inside the Solanaceae, Euphorbiaceae and Lamiaceae families to CGMMV host range in weeds. Thus, weeds reservoir within and surrounding infected fields needs to be considered as a potential source for CGMMV infection of cultivated plants.