Elimination of Grapevine fleck virus by in vitro Chemotherapy

Starting from the well-known antimicrobial properties of silver nanoparticles, the goal of this study is to evaluate the influence of two “green” recipes, namely an alcoholic extract of Dryopteris filix-mas (L.) Schott and a dispersion of silver nanoparticles phytosynthesized using the extract on grapevine pathogens. The influence of some grapevine parameters (pith/wood rapport, soluble sugars, starch, total sugars, total water content, length of young shoots, number of grapes) in field experiments was also studied. The study was conducted on four clones (Feteasca alba 97 St., Feteasca neagra 6 St., Feteasca regala 72 St., and Cabernet Sauvignon 131 St.) located in vegetation pots inside a greenhouse. For the phytosynthesis of the silver nanoparticles (AgNPs) we used a scaled-up technology, allowing us to obtain large quantities of nanoparticles-containing solution. The AgNPs analysis by X-ray diffraction and transmission electron microscopy confirmed the synthesis of spherical and quasi-spherical nanoparticles of 17 nm average diameter and 6.72 nm crystallite size. The field experiments registered different responses of the four clones to the treatment, using both the natural extracts and phytosynthesized nanoparticles solution. Both recipes exhibited a protective effect against the Uncinula necator pathogen. For the treatment using phytosynthesized nanoparticles, significant increases in the pith/wood ratio for white wine clones (Feteasca alba 97 St. and Feteasca regala 72 St.) were observed. The biochemical analyses revealed other significant increases of soluble sugars (red wine clones—Feteasca neagra and Cabernet Sauvignon/second year), starch (Feteasca alba and Cabernet Sauvignon in 2021 for both clones), total sugars (Feteasca alba and Feteasca neagra in 2021 for both clones), and of total water content (Feteasca alba and Feteasca neagra in 2021 for both clones), respectively. The applied treatments also led to an increase of young shoots length and grape numbers for all clones as compared to the control (chemical pesticide), which would suggest a potential biostimulant effect of the recipes.

Grapevine leafroll disease (GLD), caused by a complex of grapevine leafroll-associated viruses (GLRaVs), is among the most widespread and economically damaging viral diseases of grapevine. While its physiological and yield impacts are well recognized, the broader ecological implications for vineyard ecosystems remain poorly understood. This review integrates traditional literature analysis with bibliometric approaches to synthesize current knowledge on GLRaV occurrence, diversity, host responses, epidemiology, diagnostics, and management. Data from 729 peer-reviewed articles were categorized into six research clusters: global occurrence and first reports, viral diversity and characterization, host–pathogen interactions, epidemiology and vector dynamics, effects on vine physiology and fruit composition, and diagnostic and management strategies. Our findings highlight GLRaVs as dynamic pathogens shaped by genetic variability, human-mediated plant trade, and ecological interactions with vectors and vineyard biodiversity. Knowledge gaps persist regarding mixed infections, underexplored viticultural regions, ecological impacts, and sustainable management. Future work should prioritize high-resolution genomics, multi-omics approaches, improved diagnostics, ecological studies, and innovative management tools. By framing GLD not only as an agronomic but also as an ecological challenge, this review provides a foundation for more holistic strategies to safeguard vineyard health and productivity.

Grapevine (Vitis spp.) is one of the most important horticultural species, but also one of the most vulnerable to viral infections. To date, 102 viruses are known to infect grapevines. Of these, some viruses cause significant economic damage worldwide, affecting the quantity and quality production, plant growth and development, and the vineyards long-lasting. Other viruses have a broad spectrum, affecting several crop plants and represent scientific curiosities for the grapevine, both because they are rarely encountered and the damages induced are negligible. This paper summarizes the main knowledge regarding the diversity of viral agents affecting grapevine and the associated symptomatology characteristics. The economic effects of viral diseases are analyzed, highlighting their influence on propagation material and grape production. Once virus-infected, grapevine plants remain infected for their entire life. Prevention of infection includes the production of certified virus-free planting material and virus testing. Thus, the propagation of healthy material, originating from authorized sources, tested and certified as virus-free, is essential for sustainable viticulture. Also, virus-elimination methods are presented (meristem/shoot tip cultures, thermotherapy, in vitro chemotherapy, electrotherapy, cryotherapy, and combined methods), which allow the regeneration of healthy, virus-free plants. The integration of these technologies into virus-free germplasm selection and conservation programs represents a priority direction for a modern viticulture, ensuring the maintenance of grapevine health, the protection of genetic diversity and the sustainability of grapevine production.