Sensitivity to fungicides of Phytophthora infestans (Mont.) de Bary in Chapingo, Mexico

Sensitivity to fungicides of Phytophthora infestans (Mont.) de Bary in Chapingo, Mexico

Chemical control of plant diseases exerts high selection pressure for the development of pathogen resistance to fungicides. The objectives of this study were to quantify the existence of late blight in Solanum tuberosum L., detect the presence of variants of the oomycete resistant to agrochemicals a...

Saved in:
Translated title: Sensibilidad a fungicidas del Phytophthora infestans (Mont.) de Bary en Chapingo, M茅xico
Journal Title: Revista Chapingo. Serie Horticultura
First author: H茅ctor Lozoya-Salda帽a
Other Authors: Martha Nayeli Martha Nayeli Robledo-Esqueda;
Patricia Rivas-Valencia;
Sergio Sandoval-Islas;
Mar铆a Teresa Beryl Colinas y Le贸n;
Cristian Nava-D铆az
Palabras clave:
Traslated keyword:
Language: English
Spanish
Get full text: https://chapingo.mx/revistas/horticultura/contenido.php?id_articulo=2436&id_revistas=1&id_revista_numero=248
Resource type: Journal Article
Source: Revista Chapingo. Serie Horticultura; Vol 23, No 3 (Year 2017).
DOI: http://dx.doi.org/10.5154/r.rchsh.2017.01.004
Publisher: Universidad Aut贸noma Chapingo
Usage rights: Reconocimiento - NoComercial (by-nc)
Categories: Life Sciences --> Agriculture, Multidisciplinary
Life Sciences --> Horticulture
Abstract: Chemical control of plant diseases exerts high selection pressure for the development of pathogen resistance to fungicides. The objectives of this study were to quantify the existence of late blight in Solanum tuberosum L., detect the presence of variants of the oomycete resistant to agrochemicals and compare the different levels of resistance in the isolates from one cycle to another. Plots of the potato cv. Fianna, susceptible to late blight (Phytophthora infestans [Mont] de Bary), were exposed to natural infection of the pathogen to detect the presence of variants of the oomycete resistant to the agrochemicals from one cycle to another, and from in vivo with respect to in vitro conditions, by applying a half dose of fungicides. The disease reached 100 % final foliar infection in treatments with ciazofamid in 2011 and with fosetyl-Al in 2012. On the other hand, mandipropamid allowed only 21-22 % infection in both years in the field. However, 49 % of the P. infestans population was susceptible, 39 % was intermediate, and 19 % was resistant to this product in vitro. Plots treated with fosetyl-Al reached 80-100 % infection in the field, while in vitro 88 and 46 % of the P. infestans populations showed intermediate resistance when exposed to high dosages of the product, and 62 % were resistant at low dosage. Isolates from field plots with natural infection exposed to ciazofamid were all sensitive in vitro. The inconsistencies of the oomycete regarding fungicide resistance/sensitivity under in vivo/in vitro conditions, as well from one year to another, do not support behavior predictability. These results expose the great genetic plasticity of the oomycete in relation to its sensitivity to fungicides.
Translated abstract: El control qu铆mico de las enfermedades de las plantas ejerce gran presi贸n de selecci贸n en el desarrollo de resistencia del pat贸geno a fungicidas. Los objetivos del presente estudio fueron cuantificar la existencia de tiz贸n tard铆o en Solanum tuberosum L., detectar la presencia de variantes del oomiceto resistentes a agroqu铆micos y comparar los diferentes niveles de resistencia en los aislados de un ciclo a otro. Se expusieron parcelas de papa var. Fianna, susceptibles al tiz贸n tard铆o (Phytophthora infestans [Mont.] de Bary), a la infecci贸n natural del pat贸geno para detectar la presencia de variantes del oomiceto resistentes a agroqu铆micos de un ciclo a otro, y bajo condiciones in vivo respecto a in vitro mediante la aplicaci贸n de medias dosis de fungicidas. La enfermedad alcanz贸 100 % de infecci贸n foliar final en tratamientos con ciazofamida en 2011 y con fosetil-Al en 2012. Por otro lado, la mandipropamida permiti贸 solamente de 21 a 22 % de infecci贸n en ambos a帽os en campo. No obstante, 49 % de la poblaci贸n de P. infestans result贸 susceptible, 39 % intermedia y 19 % fue resistente a este producto in vitro. Las parcelas tratadas con fosetil-Al alcanzaron de 80 a 100 % de infecci贸n en campo y 88 % in vitro. El 46 % de las poblaciones de P. infestans mostraron resistencia intermedia cuando se expusieron a dosis altas del producto y 62 % fueron resistentes a dosis bajas. Los aislados de parcelas con infecci贸n natural expuestos a ciazofamida fueron sensibles in vitro. Las inconsistencias del oomiceto en relaci贸n a la resistencia/susceptibilidad a los fungicidas bajo condiciones in vitro/in vivo, as铆 como de un a帽o a otro, no explican la predictibilidad del comportamiento. Estos resultados exponen la gran plasticidad gen茅tica del oomiceto en relaci贸n con su sensibilidad a los fungicidas.