Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Incidence and symptomatology of orthotospoviruses infecting horticultural crops in Mexico(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06) Mora Ugalde, María de los Ángeles; Díaz Lara, Alfredo; emimmayorquin; Valiente Banuet, Juan; Tovar Pedraza, Juan Manuel; School of Engineering and Sciences; Campus MonterreyMexico is a leading exporter of horticultural products, with agriculture representing a significant portion of the country's annual economic value. Viral diseases in crops are frequently overlooked, despite their potential to cause severe damage. This work aims to assess the presence and impact of viruses in tomatoes, bell peppers, and lettuce, particularly by those viral agents belonging to the genus Orthotospovirus. Despite the importance of tomatoes in Mexico, limited research has addressed the incidence of orthotospoviruses in their production. Consequently, field surveys were conducted in major horticultural regions of Mexico, where symptomatic and asymptomatic tomato plants were sampled and tested for Orthotospovirus infection, including tomato spot wilt virus (TSWV, Orthotospovirus tomatomaculae), Impatiens necrotic virus (INSV, Orthotospovirus impatiensnecromaculae), ground ring spot virus (GRSV, Orthotospovirus arachianuli), tomato chlorotic spot virus (TCSV, Orthotospovirus tomatoflavi), watermelon silver mottle virus (WSMoV, Orthotospovirus citrullomaculosi) and melon yellow spot virus (MYSV, Orthotospovirus meloflavi) using molecular diagnostics. Likewise, the prevalence of INSV in lettuce was determined through ImmunoStrips, reverse transcription PCR (RT-PCR), and sequence analysis, representing the first identification of INSV in the Bajio region. Another critical aspect of this work includes cross-infection dynamics in bell peppers. Using high-throughput sequencing (HTS), a natural mixed infection by INSV and tomato brown rugose fruit virus (ToBRFV, Tobamovirus fructirugosum) was discovered, which may have implications for the pathogen-host interaction. Overall, the results of this study will contribute to understanding the distribution and economic impact of orthotospoviruses in Mexico, as well as their interactions with other plant viruses. Finally, this research seeks to increase awareness among growers and stakeholders about the risks these viruses pose to horticultural production in Mexico and highlights the importance of disease surveillance and management strategies.
- Quality assessment and validation of digital PCR (dPCR) for grapevine virus diagnosis(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-11) Hernández Pérez, Daniella María Joselyn; Díaz Lara, Alfredo; emipsanchez; Carrillo Tripp, Jimena; Rodríguez García, Manuel; School of Engineering and Sciences; Campus MonterreyGrapevine is a highly economically important crop in Mexico. However, it can be affected by several pathogens, including viruses that can cause significant crop losses. It is important to identify early the infected plants to manage the disease correctly and prevent economic losses. Traditional detection methods have drawbacks, such as limited sensibility and accuracy. Digital PCR (dPCR) is an innovative method that claims to be more sensitive and reproducible than the routine method for virus identification: quantitative PCR (qPCR). This study assesses reverse transcription dPCR (RT-dPCR) as a method for the detection and quantification of RNA grapevine viruses focusing on grapevine virus A (GVA), grapevine fanleaf virus (GFLV), grapevine leafroll-associated virus 3 (GLRaV-3), and grapevine Pinot gris virus (GPGV). This assessment was performed using positive controls and comparing the limit of detection (LoD) results of RT-dPCR against the results obtained by RT-qPCR. ANOVA results showed that the PCR technique (RT-dPCR or RT-qPCR) and the virus (GVA, GLFV, GPGV, and GLRaV-3) were statistically significant in the results of the comparison of LoD. Furthermore, the replicates were non-significant according to ANOVA, showing high repeatability in both RT-qPCR and RT-dPCR. Tukey test demonstrated that RT-dPCR is significantly more sensitive than RT-qPCR, with a statistically reliable difference of 95% trust, especially in low-viral-load viruses such GPGV, which detection showed also to be statistically different than the other viruses. Additionally, a field study was performed to identify the presence or absence of each virus in 45 grapevine samples evaluated with RT-qPCR and RT-dPCR. Several false negative results were generated by RT-qPCR, which only reported positive results to 62.5% of the GVA infected samples, 85.7% of the samples contaminated with GLRaV-3, 38.9% of GPGV positive samples and for GFLV only 12.5% of the infected samples were identified. These results confirm the effectiveness of RT-dPCR as a sensitive method for RNA virus detection in grapevine, enabling early diagnosis and optimal management of viral infections in grapevine crops.