Reduced sensitivity to azoxystrobin is stable in Monilinia fructicola isolates

Autor(es)

Primiano, Isabela Vescove ; Edwards Molina, Juan Pablo ; May De Mio, Louise Larissa ; Peres, Natalia Aparecida ; Amorim, Lilian

• Tipo de documento: Artigo Científico
• Fonte: CIENTIA AGRICOL; v. 74, n. 2, p. 5-pg., 2017-03-01.

Resumo

A shift towards declining azoxystrobin sensitivity has been previously documented in a collection of Brazilian Monilinia fructicola isolates, but information on the stability of this trait after in vitro sub-culturing is not available. In this study, one highly-sensitive isolate and two isolates with reduced sensitivity to azoxystrobin, not exhibiting point mutations at codons 129, 137 and 143 in the target gene of cytochrome b were used. Two independent experiments consisted of 10 weekly transfers of each strain in potato dextrose agar (PDA). Conidial production and germination were quantified in the initial culture and, again, after the third, sixth and tenth transfer. Measures of mycelial growth were obtained in colonies growing on PDA amended with azoxystrobin at 1 mu g mL(-1) and salicylhydroxamic acid at 100 mu g mL-1. Data were normalized to mycelial growth rate after each of the 10 transfers. The colony diameter in the less sensitive isolates was stable across the transfers in the PDA amended with the fungicide. The conidial production and mycelial growth rate did not decrease in non-amended media either. Our results suggest that the trait of reduced sensitivity to azoxystrobin is stable under no selection pressure for azoxystrobin. (AU)

• Processo FAPESP: 13/20285-0 - Adaptabilidade de isolados de Monilinia fructicola com diferentes níveis de sensibilidade a azoxistrobina
• Beneficiário: Isabela Vescove Primiano
• Modalidade de apoio: Bolsas no Brasil - Mestrado