Efficient method, based on microplate readers, to detect resistance to triazole (DMI) and strobilurin (QoI) fungicides in wheat blast pathogen populations

Author(s)

Priscila Santos Casado ^[1] ; Giselle de Carvalho ^[2] ; Paulo Cezar Ceresini ^[3] ; Vanina Lilian Castroagudín ^[4] ; Omar Jorge Sabbag ^[5] ; Samara Nunes Campos Vicentini ^[6] ; João Leodato Nunes Maciel ^[7]

Affiliation

^[1] Universidade Estadual Paulista - Brasil

^[2] Universidade Estadual Paulista - Brasil

^[3] Universidade Estadual Paulista - Brasil

^[4] Universidade Estadual Paulista - Brasil

^[5] Universidade Estadual Paulista - Brasil

^[6] Universidade Estadual Paulista - Brasil

^[7] Empresa Brasileira de Pesquisa Agropecuária - Brasil

• Document type: Journal article
• Source: Summa Phytopathologica; v. 44, n. 3, p. 236-244, 2018-09-00.

Abstract

ABSTRACT This study proposes the application of a method based on an automated microplate reader to detect resistance to triazole (DMI) and strobilurin (QoI) fungicides in populations of the plant pathogenic hemibiotrophic fungus Pyricularia graminis-tritici (Pygt) from wheat. Availability of an accurate, more rapid and efficient method to detect eventual reduction in sensitivity to fungicides could contribute to facilitate the decision making on chemical management of wheat blast in the country. There are reports of reduction in the sensitivity of triazoles to control wheat blast and evidence of widespread reduction in the sensitivity to strobilurins in populations of the pathogen in Brazil. The microplate method was accurate in discriminating the phenotypic variation in sensitivity among isolates of the pathogen to the DMI fungicides tebuconazole and epoxiconazole and to the QoI fungicide azoxystrobin. Economically, both methods represent high cost, therefore, the efficiency of these methods should be compared. The microplate method was more efficient in the use of resources, with a total operating cost 33% inferior to that of the Petri dish method. Together, the factors accuracy, celerity and efficiency in the use of resources indicated that the microplate method can be used to monitor resistance to fungicides among populations of the wheat blast fungus in the Brazilian agroecosystem. (AU)

• FAPESP's process: 17/03403-0 - Bioprospecting of fluorescent bacteria of the genus Pseudomonas in the biocontrol of the foliar blight of signal grass (Urochloa brizantha)
• Grantee: Samara Nunes Campos Vicentini
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/10453-8 - The rise of Pyricularia tritici sp. Nov. as the wheat blast pathogen in Brazil: sympatric speciation inferred from multilocus gene phylogeny, pathogenicity spectra and avirulence genes evolution
• Grantee: Paulo Cezar Ceresini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/10655-4 - Unraveling the local origin of the wheat blast pathogen (Magnaporthe oryzae) in Central-Southern Brazil and evidence for the emergence of resistance to Strobilurin fungicides in the pathogen populations
• Grantee: Paulo Cezar Ceresini
• Support Opportunities: Regular Research Grants