Planta sentinela para o monitoramento do vetor Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae) e desenvolvimento de um genossensor colorimétrico para detecção de Luteovirus pavhordei

Abstract

Winter cereals, particularly wheat, barley and oats, constitute fundamental pillars of global food security and contemporary agricultural economy. These crops play multiple strategic roles in production systems, providing essential nutrients for human and animal nutrition, while also integrating rotation systems that optimize land use. However, the productivity of these crops is significantly limited by pests and diseases, particularly by aphids. Among the most relevant aphid species, Rhopalosiphum padi (Linnaeus) stands out, a hemimetabolous insect with cosmopolitan distribution, polyphagous nature and high dispersal capacity. Its most devastating impact occurs through the transmission of barley yellow dwarf virus (BYDV), a virus belonging to the genus Luteovirus. BYDV is responsible for the cereal yellow dwarf syndrome, causing production losses that can exceed 80% in untreated crops. Transmission occurs in a persistent-circulatory and non-propagative manner, where R. padi acquires the virus by feeding on infected plants and transports it internally through complex molecular mechanisms mediated by bacterial endosymbionts. The BYDV complex comprises several viral species, including BYDV-PAV, BYDV-GAV and BYDV-MAV, with variable geographic distribution. Given the economic and phytosanitary relevance of R. padi and BYDV, it becomes imperative to develop effective monitoring and diagnostic strategies. In this context, sentinel plants emerge as promising tools for early monitoring of the vector. Experimental studies demonstrate that oats exhibit superior efficiency as a sentinel plant compared to wheat, exhibiting greater colonization consistency, greater population support capacity and greater probability of detecting R. padi, with a preference ratio of 56.4:1. This superiority allows optimizing early monitoring strategies, facilitating assertive decision-making in integrated pest management. Complementing monitoring strategies, rapid, sensitive and low-cost diagnostic methods are essential for efficient BYDV detection. In this perspective, colorimetric genosensors based on gold nanoparticles functionalized with thiolated DNA probes represent an innovative approach for visual BYDV diagnosis. These devices demonstrate satisfactory analytical performance, with high linearity, adequate sensitivity and detection and quantification limits compatible with phytosanitary applications. Stability exceeding 95% for up to 40 days under refrigeration reinforces the potential of this technology for implementation in phytosanitary monitoring programs for winter cereals. Therefore, the integration of knowledge about R. padi biology, BYDV transmission dynamics, the efficiency of sentinel plants and the development of innovative diagnostic tools constitutes an essential multidisciplinary approach to mitigate economic losses, reduce dependence on chemical insecticides and ensure the sustainability of cold-season cereal production chains on a global scale.