Emna Yahyaoui

Plant viral diseases threaten the tomato agricultural industry. A smart decentralized diagnostic network was realized across the main Sicilian tomato-producing provinces for real-time detection/monitoring of Begomovirus solanumdelhiense (tomato leaf curl New Delhi virus—ToLCNDV), transmitted by Bemisia tabaci, Tobamovirus fructirugosum (tomato brown rugose fruit virus—ToBRFV), Orthotospovirus tomatomaculae (tomato spotted wilt virus—TSWV) and Amalgavirus lycopersici (southern tomato virus—STV). The network deployed smart portable thermocyclers and ready-to-use molecular diagnostic kits (real-time RT-LAMP, RT-qPCR). Data were remotely analyzed and in situ application of the developed kits was evaluated. Results revealed widespread STV infection (>70%) across all provinces, a variable ToBRFV presence with higher incidence in Ragusa (65%) and Siracusa (55.6%) provinces, ToLCNDV mainly concentrated in Siracusa (61.4%) and Trapani (60.2%) provinces, and localized TSWV outbreaks. ToLCNDV detection in Bemisia tabaci MED specimens confirmed the vector’s role in field transmission (up to 100% incidence). Performance comparison between laboratory and point-of-care conditions showed comparable accuracy, specificity, robustness, and rapid, cost-effective virus detection/monitoring. This diagnostic network enhances early diagnosis and timely phytosanitary interventions in tomato crops. The system supports integrated management strategies by reducing diagnostic delays and improving outbreak containment, control measures application and agroecosystem stability.

Citrus mal secco is a destructive tracheomycotic disease caused by the mitosporic fungus Plenodomus tracheiphilus (Petri) Gruyter, Aveskamp, and Verkley, severely affecting cultivated citrus species, particularly lemon trees in the Mediterranean region. A novel diagnostic assay based on real-time loop-mediated isothermal amplification (LAMP) was developed for the rapid detection of P. tracheiphilus. A set of six LAMP primers was designed to specifically target a 204-nucleotide sequence within the ITS1-5.8S-ITS2 region of nuclear rRNA genes. The assay’s sensitivity, specificity, exclusivity, and inclusivity were evaluated on a panel of 21 isolates and compared with conventional PCR and real-time quantitative PCR. Results showed that the developed real-time LAMP assay could rapidly detect the pathogen genomic DNA within only 15 min, with no registered cross-reactivity with nontarget fungal isolates from citrus plants or Citrus species. Moreover, reliable amplification was achieved using minimally processed samples. Specifically, two rapid extraction methods have been tested for an in-field plant diagnosis of P. tracheiphilus directly from the leaf surface. Overall, the developed real-time LAMP assay provides a potential tool for a quick, simple, specific, and sensitive detection of P. tracheiphilus, allowing an early disease prediction and reducing the risk of epidemics.