Mexican Journal
of Phytopathology

• Open access Prueba
• Phytopathological note

Characterization of the virome in broad bean: First detection of Potyvirus phaseoluteum and Orthotospovirus impatiensnecromaculae in Montecillo, Texcoco, Mexico

By Erick Ortega Piña, Daniel Leobardo Ochoa Martínez*, Reyna Isabel Rojas Martínez, Alfredo Díaz Lara

* Corresponding Author. Email: ldaniel@colpos.mx / Institution: Colegio de Postgraduados

Accepted: 12/August/2024 – Published: 26/July/2024 – DOI: https://doi.org/10.18781/R.MEX.FIT.2402-8

• Download PDF
• Citation export
• Supplementary material

Abstract Background/Objective. In broad bean (Vicia faba) crops established in Montecillo, Texcoco, State of Mexico, 100% of plants were observed with viral symptoms consisting of mosaic, mottling, leaf curling, wilting and a notable decrease in plant development. These symptoms led to a significant reduction in seed yield and quality. In this context, the present study was carried out with the objective of identifying the viral species associated with these symptoms.

Materials and Methods. The experimental strategy consisted of extraction of total RNA from leaves showing the aforementioned symptoms, followed by nextgeneration sequencing.

Results. In the results, the complete genomes of Orthotospovirus impatiensnecromaculae (before impatiens necrotic spot virus) and two isolates of the Potyvirus phaseoluteum (before bean yellow mosaic virus) were obtained. The phylogenetic analysis revealed that the isolate of O. impatiensnecromaculae (INSV CPMEX) shows significant divergences from those previously reported in other plant species. On the other hand, the two P. phaseoluteum isolates (BYMV CP1MEX and BYMV CP2MEX) proved to be different from each other, being related to isolates reported in Sudan and Iran.

Conclusion. This result suggests considerable genetic diversity among the viruses associated with viral symptoms in faba bean crops in the region, which underlines the importance of accurate identification for the management and control of these viral infections.

Keywords: Next Generation Sequencing, Potyvirus, Orthotospovirus, RNA, mosaic, mottle, viral divergence

Figure 1. Detection of Orthotospovirus impatiensnecromaculae and Potyvirus phaseoluteum in broad bean plants using RT-PCR. A) Product of RT-PCR of a 438 bp fragment of the L segment that codifies the viral replicase of O. impatiensnecromaculae: MPM= Molecular weight marker 100 bp PROMEGA, negative control (-). Lanes 1, 3, 4, 9, 10, 13, 14 and 15 broad bean plant samples with symptoms of mosaic, mottling, leaf curling and wilting. B) Product of RT-PCR of a 319 bp fragment of the ORF of the P. phaseoluteum that codifies for the nucleocapsid MPM= Molecular weight marker 100 bp PROMEGA, negative control (-). Lanes 1, 2, 3, 4, 9, 10, 13, 14 and 15 broad bean plant samples with symptoms of mosaic, mottling, leaf curling and wilting. The sequences of the amplicons obtained had a 99% coverage and 99% identity with P. phaseoluteum and O. impatiensnecromaculae isolates deposited in the GenBank, respectively

Figure 2. Phylogenetic tree of the Potyvirus phaseoluteum CP1MEX and BYMV CP2MEX isolates using the General-Time- Reversible model and the maximum likelihood method with 500 bootstrap replicates.

Table 1. Primers designed to verify the presence of Potyvirus phaseoluteum (Pp) and Orthotospovirus impatiensnecromaculae (Oi) in broad bean foliar tissue with symptoms of mosaic, mottling, leaf curling, wilting and growth reduction.