Detection of Plasmopara halstedii in sunflower seeds: A case study using molecular testing.

Plasmopara halstedii (Farl.) Berl. & De Toni causing downy mildew of sunflower is responsible for considerable economic losses worldwide. Because P. halstedii can be seed-transmitted, monitoring of seeds for pathogen contamination is important for the sunflower seed trade. The relevance of asymptoma...

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Detalles Bibliográficos
Autores principales: Martínez, Ana Laura, Quiroz, Facundo Jose, Carrera, Alicia Delia
Formato: info:ar-repo/semantics/artículo
Lenguaje:Inglés
Publicado: Elsevier 2021
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12123/10141
https://www.sciencedirect.com/science/article/pii/S1658077X21000503
https://doi.org/10.1016/j.jssas.2021.04.007
Descripción
Sumario:Plasmopara halstedii (Farl.) Berl. & De Toni causing downy mildew of sunflower is responsible for considerable economic losses worldwide. Because P. halstedii can be seed-transmitted, monitoring of seeds for pathogen contamination is important for the sunflower seed trade. The relevance of asymptomatic or latent infections as factors of disease spread have not been studied by molecular techniques. A molecular marker based on a putative effector gene of P. halstedii was used to examine the pathogen’s presence in asymptomatic sunflowers growing near patches of mildewed plants in naturally infected fields. The method based on conventional PCR was highly sensitive for detection of P. halstedii in DNA from whole seeds. By the application of this protocol, we found that all seed samples obtained from symptomatic plants amplified the expected fragment, whereas the diagnostic marker identified the presence of pathogen in one out of 21 asymptomatic plants. Possible uses of this marker to detect downy mildew in seed from asymptomatic plants or for race identification are discussed.