The role of weeds in the epidemiology of pospiviroids

Abstract

Many weeds that are closely associated with horticultural activities are known as natural reservoirs of plant viruses. However, whether these weeds can also serve as hosts of pospiviroids is not well known. Pospiviroids are naked, non-coding RNA pathogens that cause severe economic damage in many solanaceous crops. In this study, we examined the overall risk of pospiviroid spreading from weeds to economically important crops, by combining the results from previous inoculation studies with new results coming from a survey, a contact experiment and an inoculation experiment. A survey of commercial ornamental glasshouses revealed that ornamental plants mainly belonging to the Solanaceae harbour pospiviroids, in contrast to weed species sampled in the same places. No new weed hosts could be identified after testing weeds that grew in contact with Tomato apical stunt viroid (TASVd)-infected plants of tomato (Solanum lycopersicum) and jasmine nightshade (Solanum jasminoides) in an experimental glasshouse. Finally, in mechanical inoculation experiments with TASVd, none of the six tested weed species were determined to be a host at 6 weeks after inoculation. Commonly occurring weed species therefore do not appear to play a significant role as reservoir hosts for pospiviroids. This does not rule out other potential weed hosts that have not yet been tested. Inoculation studies should include rigorous experimental protocols with a sufficient number of replicated as well as adequate positive controls. The information gained through this study may prove useful in future risk assessments for the pospiviroid group

Global Advances in Tomato Virome Research: Current Status and the Impact of High-Throughput Sequencing

“…Viroid infection in tomatoes results in growth reduction or stunting accompanied by leaf distortion or epinasty, although symptoms vary greatly among viroid strains and tomato cultivars (Mackie et al, 2019). Aside from tomato and other crops and ornamentals (van Brunschot et al, 2014a), pospiviroids were also found to be harbored in several weed species, which were reported as their natural reservoir (Van Bogaert et al, 2015;Mackie et al, 2016). Majority of viroids are transmitted mechanically through infected tools and seldom through seeds or pollen; however, the most efficient transmission of viroids is through vegetative propagation of infected material (Flores et al, 2005).…”

Pospiviroides de importância para hortaliças e ornamentais: panorama dos aspectos fitopatológicos e dos riscos para os sistemas agrícolas brasileiros

“…Vale ressaltar que o PSTVd e o TASVd foram detectados nos estile-tes de 20 a 40% de adultos de M. persicae. Porém, não foi confirmada a capacidade do afídeo transmitir esses viroides ( VAN BOGAERT et al 2015).…”

Promoting Jatropha Agriculture for Sustainable Soil Capital Improvement: A Win-Win Technology for Rehabilitating Degraded Lands in Africa

“…Weeds also have the advantage of being more adept at utilizing CO2 (Clements et al 2014). Weeds are important components in cropping systems either by acting as a pest itself or by harboring vectors and vector-borne diseases (Van Bogaert et al 2015). Weeds inhibit crop growth by outcompeting crops for essential nutrients, space, and water (Goyal et al 2015).…”