| Autor: |
D'Ávila LS; Graduate Program in Plant Pathology, Universidade de Brasília, 70910-900, Brasília, DF, Brazil., De Filippi MCC; Graduate Program in Plant Pathology, Universidade de Brasília, 70910-900, Brasília, DF, Brazil.; Embrapa Rice and Beans, 75375-000, Santo Antônio de Goiás, GO, Brazil., Café-Filho AC; Graduate Program in Plant Pathology, Universidade de Brasília, 70910-900, Brasília, DF, Brazil. |
| Jazyk: |
angličtina |
| Zdroj: |
Plant disease [Plant Dis] 2021 Jun; Vol. 105 (6), pp. 1771-1780. Date of Electronic Publication: 2021 Apr 29. |
| DOI: |
10.1094/PDIS-08-20-1806-RE |
| Abstrakt: |
The long-term dynamics of fungicide resistance of the rice blast fungus Pyricularia oryzae was monitored by examining the reaction of the fungal field isolates, collected over a period of 26 years, to the active ingredients of commercially relevant fungicides. The in vitro sensitivity of all isolates was measured against quinone outside inhibitors (QoI), melanin biosynthesis inhibitors, and sterol demethylation inhibitor (DMI) fungicides, namely azoxystrobin (as a QoI), tricyclazole (as a melanin biosynthesis inhibitor), tebuconazole (as a DMI), and trifloxystrobin + tebuconazole (QoI + DMI). Over the 26-year collection period, a gradual rise in the EC 50 estimates for mycelial growth sensitivity was observed for all fungicides, but most strikingly for azoxystrobin. A rise in conidial germination and appressorium formation was also noted, most markedly for azoxystrobin. Consistently, the earlier isolates were much more sensitive to the active ingredients than the more contemporary isolates. The sequencing of the amplified cyt b fragment distinguished two haplotypes, H1 and H2. Haplotype H1 (six isolates) contained the G to C transversion at codon 143 (resulting in change G143A), linked to the resistant phenotype QoI-R. Haplotype H2 (40 isolates), gathered the isolates sensitive to QoI. This work documents the gradual rise in the frequency of fungicide-resistant isolates in P. oryzae rice populations on a long-term basis. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
