Selection, Fitness, and Control of Grape Isolates of Botrytis cinerea Variably Sensitive to Fenhexamid
Of 683 Botrytis cinerea isolates collected from a fungicide-trial vineyard, 31 were classified as putatively resistant to fenhexamid (50% effective concentration [EC50] ≥ 0.1 μg/ml). For the resistant isolates that survived and sporulated in culture, colony expansion and conidial germination frequen...
| Veröffentlicht in: | Plant disease. - 1997. - 98(2014), 2 vom: 01. Feb., Seite 233-240 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2014
|
| Zugriff auf das übergeordnete Werk: | Plant disease |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Of 683 Botrytis cinerea isolates collected from a fungicide-trial vineyard, 31 were classified as putatively resistant to fenhexamid (50% effective concentration [EC50] ≥ 0.1 μg/ml). For the resistant isolates that survived and sporulated in culture, colony expansion and conidial germination frequency was significantly reduced relative to the mean of 30 representative baseline isolates (EC50 = 0.03 μg/ml). Grape berries were inoculated with four isolates representing a range of fenhexamid sensitivities and treated preventively or curatively with fenhexamid concentrations (150 to 600 mg/liter) representing 25 to 100% of the recommended rate. All treatments significantly delayed disease onset and progress caused by isolates with EC50 values of 0.03 and 0.15 μg/ml but provided little to no control of isolates with EC50 values of 0.32 and 62.5 μg/ml. The latter isolate exhibited a previously unreported F427V mutation of ERG27, an enzyme of ergosterol biosynthesis. In a duplex quantitative polymerase chain reaction test, the ratio of pathogen/host DNA increased significantly for 14 days after inoculation of untreated berries with a baseline isolate but declined slightly in berries treated with fenhexamid at 600 mg/liter 1 day post inoculation. In the vineyard, disease control was affected by the number and rate of fenhexamid applications but B. cinerea isolates with EC50 ≥ 0.1 μg/ml were not preferentially selected |
|---|---|
| Beschreibung: | Date Revised 20.11.2019 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 0191-2917 |
| DOI: | 10.1094/PDIS-07-13-0746-RE |