Distribution and fitness of isolates of Botrytis cinerea with multiple fungicide resistance in Spanish greenhouses

Abstract

Forty‐nine greenhouses of vegetable crops were surveyed in southeast Spain at the beginning of the disease season in December 1992 to estimate frequencies of resistance to benzimidazoles, dicarboximides and N‐phenylcarbamates (NPC) in B. cinerea. Out of 261 isolates collected, 28% were sensitive to both benzimidazoles and dicarboximides, 15% were benzimidazole‐resistant and dicarboximide‐sensitive, 8% were benzimidazole‐sensitive and dicarboximide‐resistant and 46% were benzimidazole‐ and dicarboximide‐resistant. Resistance to benzimidazole, dicarboximide and N‐phenylcarbamate was determined by measuring the ability of each isolate to grow in the presence of carbendazim, procymidone and diethofencarb fungicides respectively. Carbendazim‐ or procymidone‐ resistant isolates were found in all surveyed greenhouses. Three isolates were found with resistance to carbendazim, procymidone and diethofencarb collected in two adjacent greenhouses that were sprayed with the carbendazim and diethofencarb mixture. All other isolates were sensitive to the mixture because they were either sensitive to carbendazim and resistant to diethofencarb or vice versa. Fitness of 31 isolates of B. cinerea was determined in vivo by measuring their sporulation and lesion growth rate on leaf disks. No fitness costs were associated with resistance to iprodione (dicarboximide) and benomyl (benzimidazole). Isolates with EC50 values higher than 101 mg/L for benomyl and 1.6 mg/L for iprodione were considered to be field resistant (they caused visible lesions on cucumber leaf disks treated with each fungicide).

Survey of Fungicide Resistance for Chemical Control of Botrytis cinerea on Paprika

“…The gray mold pathogen B. cinerea develops mainly on fruits, leaves or petals (Dik & Elad, 1999), threatens the greenhouse paprika productivity throughout the world, and is usually managed by frequent use of prophylactic fungicides (Braun and Sutton, 1984;Bulger et al, 1987;de Visser, 1996;Raposo et al, 1996), which may lead to the development of multiple resistant pathogen population (Moorman and Lease, 1992;Raposo et al, 1996). While the new generation of fungicides like azoles and strobilurins showed limited effectiveness against this pathogen (Vermeulen et al, 2001), many fungicides have been applied routinely on glasshouse crops to control gray mold disease caused by B. cinerea.…”

Scatter: a novel family of miniature inverted‐repeat transposable elements in the fungus Botrytis cinerea

“…Botrytis cinerea (anamorph of Botryotinia fucheliana) is a phytopathogenic fungus with significant genetic diversity [20,21], which is thought to be associated with fungicide resistance and broad host plant fitness [22]. Such genetic diversity may result from TE activity, which is recognized as an important cause of genetic variation, particularly in the organisms without a sexual phase [23].…”

“…Although currently used classification systems for TEs largely differ from one another on a lower level, it has been commonly accepted that, at the highest level, Miniature inverted-repeat transposable elements (MITEs), first discovered in maize [7] and found to be widespread in eukaryotes and prokaryotes [6], are a heterogeneous group of non-autonomous DNA transposons that share structural characteristics, including short length (<600 bp), conserved terminal inverted repeats (TIRs), non-coding capacity of internal sequence, target site duplications (TSDs), high A þ T content, tendency to insert into intergenic regions, and the potential to form stable secondary structure [6]. Base on their TIR and TSD sequence signatures, most MITEs can be assigned to one of two major superfamilies, Tourist and Stowaway, although a few ones cannot be classified into a known family [8][9][10].Previously, MITEs were most extensively studied in higher eukaryotes and were thought to play an important role in genome evolution and the regulation of gene transcription [1] [18,19], and their further roles remain to be elucidated.Botrytis cinerea (anamorph of Botryotinia fucheliana) is a phytopathogenic fungus with significant genetic diversity [20,21], which is thought to be associated with fungicide resistance and broad host plant fitness [22]. Such genetic diversity may result from TE activity, which is recognized as an important cause of genetic variation, particularly in the organisms without a sexual phase [23].…”

Sensitivity of four isolates of <i>Clonostachys rosea</i> to pesticides used in the strawberry crop in Brazil

“…is an important pathogen of strawberry, causing gray mold on all aerial plant organs, mainly fruits. Despite reports on the resistance of B. cinerea to fungicides, 1,2) these chemicals are commonly sprayed to control gray mold. 2) To reduce fungicide usage, the biological control of B. cinerea is being evaluated in several crops.…”

“…Despite reports on the resistance of B. cinerea to fungicides, 1,2) these chemicals are commonly sprayed to control gray mold. 2) To reduce fungicide usage, the biological control of B. cinerea is being evaluated in several crops. [3][4][5][6][7] A promising biocontrol agent is the fungus Clonostachys rosea (Link: Fr.)…”