Australasian Plant Pathology (2014) 43, 639-651

Dong-Xia Wu, Xiao-Ke Zhang, Ji Wang, Jian-Xin Wang, Ming-Guo Zhou and Chang-Jun Chen (2014)
Baseline sensitivity of Botrytis cinerea and risk assessment of developing resistance to the novel fungicide Y5247
Australasian Plant Pathology 43 (6), 639-651
Abstract: Y5247 (development code no.), a quinone-outsider-inhibitor (QoI), is a novel fungicide with a broad-spectrum of fungicidal activity against plant filamentous fungi, including B. cinerea. Compared to azoxystrobin, Y5247 had a stronger inhibitory effect on mycelial growth of B. cinerea. The baseline sensitivity of 100 strains showed the EC50 values for Y5247 inhibiting mycelial growth of B. cinerea ranged from 0.0033 to 0.3921 μg/mL with a mean of 0.0859 (±0.0788) μg/mL and the frequency distribution of EC50 values was unimodal. Mutants with stable resistance to Y5247 were not obtained following exposure to ultraviolet light or chemical mutagenesis. However, strains resistant to Y5247 were collected from greenhouses where other QoI fungicides had frequently been sprayed to control gray mold of strawberry. Among the Y5247-resistant strains, EC50 values for Y5247 and other QoIs, including azoxystrobin, kresoxim-methyl and pyraclostrobin, were positively correlated. No cross-resistance was detected between Y5247 and the other fungicides with different modes of action such as carbendazim, diethofencarb, boscalid, fluazinam, procymidone, and fludioxonil. The Y5247-resistant strains showed comparable fitness in mycelial growth, sporulation and pathogenicity to that of Y5247-sensitive strains. The risk of B. cinerea developing resistance to Y5247 was assessed as high. Analysis of cytb in B. cinerea showed that all the Y5247-sensitive and resistant strains carried the type II cytb (which lacks the intron Bcbi-143/144) and the point mutation G143A occurred in all the resistant strains tested.
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Link to article at publishers website
Database assignments for author(s): Chang-Jun Chen, Ming-Guo Zhou

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea	Strawberry (Fragaria)