RESISTANCE OF Botrytis cinerea FROM STRAWBERRY (Fragaria x ananassa Duch.) TO FUNGICIDES IN MICHOACAN MEXICO
Gray mold caused by Botrytis cinerea Pers. is one of the most important diseases of strawberry ( Fragaria x ananassa Duch.), and fungicide resistance is a concern. The objective of this research was to evaluate the sensitivity of B. cinerea isolates to the fungicides iprodione and thiophanate-methyl...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | México |
| Institución: | Universidad Autónoma Chapingo |
| Repositorio: | Redalyc-UACHP |
| OAI Identifier: | oai:redalyc.org:30253291007 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=30253291007 |
| Access Level: | acceso abierto |
| Palabra clave: | Agrociencias benzimidazole dicarboximides Fungicide resistance |
| Sumario: | Gray mold caused by Botrytis cinerea Pers. is one of the most important diseases of strawberry ( Fragaria x ananassa Duch.), and fungicide resistance is a concern. The objective of this research was to evaluate the sensitivity of B. cinerea isolates to the fungicides iprodione and thiophanate-methyl in two strawberry-producing areas in Mexico. Sixty-two B. cinerea isolates collected from strawberry fruits from Maravatio Valley (MV) and Zamora-Jacona Valley (ZJ) in Michoacan, Mexico, were used to determine the sensitivity distribution based on mycelium growth (MG) and conidial germination (CG). Each monosporic isolate was grown in 4 plates containing media amended with 0, 0.1, 0.5, 1, 10, 50 and 100 m g mL - 1 of iprodione and 0, 0.1, 10, 100, 1000 and 2000 m g mL - 1 thiophanate-methyl, and the experiment was conducted twice. The effective concentration (EC 50 ) that inhibits 50 % of mycelial growth and conidial germination was determined for each isolate-fungicide combination by fitting the log-logistic model to the data. Fungicide sensitivity distributions were illustrated by box plots and histograms, and compared by the Kolmogorov-Smirnov non-parametric test. For iprodione, there were significant differences between the sensitivity distributions (p £ 0.0001) of both of the sampling areas for mycelia. In MV, the median EC 50 was 0.35 m g mL - 1 , while that of the ZJ isolates was 1.5 m g mL - 1 . There were no significant differences in the sensitivity distributions of CG (p=0.47) between producing areas for conidia (median EC 50 = 3.73 m g mL - 1 ). For thiophanate-methyl, the sensitivity distribution for mycelia was scattered and bimodal, with significant differences between the sampling areas (p £ 0.002). The median EC 50 of MG was 3.11 m g mL - 1 in MV, and 2000 m g mL - 1 in ZJ. There were no significant differences between the sensitivity distributions from MV and ZJ in the conidial germination assay (p=0.13, Ks=1.17). The EC 50 varied from 0.01 to >2000 m g mL - 1 (median=2.01 m g mL - 1 ). Resistance in B. cinerea to thiophanate-methyl and iprodione is widespread in strawberry-producing areas in Michoacan. |
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