Fitness, Competitive Ability, and Mutation Stability of Isolates of <i>Colletotrichum acutatum</i> from Strawberry Resistant to QoI Fungicides

Forcelini, Bruna B; Rebello, Carolina Suguinoshita; Wang, Nan‐Yi; Peres, Natália A.

doi:10.1094/phyto-09-17-0296-r

Cited by 52 publications

(26 citation statements)

References 35 publications

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“…Over the past few years, resistance of Colletotrichum spp. to the quinone-outside inhibitors (QoI) group of fungicides have appeared (Forcelini et al 2018) and QoI resistant Colletotrichum isolates have been recovered from apples (Munir et al 2016).…”

Section: Colletotrichum Sppmentioning

confidence: 99%

Latent postharvest pathogens of pome fruit and their management: from single measures to a systems intervention approach

Wenneker

Thomma

2020

Eur J Plant Pathol

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Postharvest diseases of pome fruit are typically caused by a wide diversity of fungal pathogens, and the list of confirmed causal agents is still growing. There is considerable knowledge on the epidemiology of wound pathogens, such as Botrytis cinerea and Penicillium expansum. In contrast, knowledge on the occurrence of the different postharvest diseases caused after latent (quiescent) infections during long-term storage and their epidemiology is limited. Well-known pathogens causing postharvest losses after latent infections are Neofabraea spp. and Colletotrichum spp., but in many cases the causal agents that occur in a specific region remain unknown and their control relies on the routine use of fungicide applications. However, due to the growing concern over the use of synthetic fungicides, alternative control measures are highly desired. Over the past years the use of physical treatments, natural compounds, and biocontrol agents have been investigated as alternatives. However, no single method has emerged that can robustly and reliably control postharvest diseases of pome fruit in practice. In this review it is argued to approach latent postharvest diseases as complex problems that require multiple interventions at different stages of the disease process in a systems intervention approach for their control. Such approach requires a deep understanding of the epidemiology of the causal agents in the orchard, fruit defence mechanisms against pathogens, and the molecular biology of host-pathogen interactions in order to develop novel disease control methods in which the deployment of resistant cultivars can be a cornerstone.

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Section: Colletotrichum Sppmentioning

confidence: 99%

Latent postharvest pathogens of pome fruit and their management: from single measures to a systems intervention approach

Wenneker

Thomma

2020

Eur J Plant Pathol

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“…59 Other studies failed to find fitness costs in resistant species such as Blumeria graminis, 60 Alternaria alternata, 61 Botrytis cinerea 62 and Colletotrichum acutatum. 63 These fitness studies, however, did not provide direct evidence for the association of fitness consequences with the G143A mutation. To evaluate the role of G143A in fungicide resistance and its impact on the fitness of fungi, the mutation was introduced into the cytochrome b of the yeast species Saccharomyces cerevisiae as a model system.…”

Section: Discussionmentioning

confidence: 95%

“…For example, conidia production of the field G143A azoxystrobin‐resistant mutant of M. oryzae is lower than that of the susceptible wild‐types . Other studies failed to find fitness costs in resistant species such as Blumeria graminis , Alternaria alternata , Botrytis cinerea and Colletotrichum acutatum . These fitness studies, however, did not provide direct evidence for the association of fitness consequences with the G143A mutation.…”

Section: Discussionmentioning

confidence: 97%

Identification and characterization of new mutations in mitochondrial cytochrome b that confer resistance to bifenazate and acequinocyl in the spider miteTetranychus urticae

Fotoukkiaii

Tan

Xue

et al. 2019

Pest Management Science

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BACKGROUND In spider mites, mutations in the mitochondrial cytochrome b Qo pocket have been reported to confer resistance to the Qo inhibitors bifenazate and acequinocyl. In this study, we surveyed populations of the two‐spotted spider mite Tetranychus urticae for mutations in cytochrome b, linked newly discovered mutations with resistance and assessed potential pleiotropic fitness costs. RESULTS We identified two novel mutations in the Qo site: G132A (equivalent to G143A in fungi resistant to strobilurins) and G126S + A133T (previously reported to cause bifenazate and acequinocyl resistance in Panonychus citri). Two T. urticae strains carrying G132A were highly resistant to bifenazate but not acequinocyl, whereas a strain with G126S + A133T displayed high levels of acequinocyl resistance, but only moderate levels of bifenazate resistance. Bifenazate and acequinocyl resistance were inherited maternally, providing strong evidence for the involvement of these mutations in the resistance phenotype. Near isogenic lines carrying G132A revealed several fitness penalties in T. urticae; a lower net reproductive rate (R0), intrinsic rate of increase (rm) and finite rate of increase (LM); a higher doubling time (DT); and a more male‐biased sex ratio. CONCLUSIONS Several lines of evidence were provided to support the causal role of newly discovered cytochrome b mutations in bifenazate and acequinocyl resistance. Because of the fitness costs associated with the G132A mutation, resistant T. urticae populations might be less competitive in a bifenazate‐free environment, offering opportunities for resistance management. © 2019 Society of Chemical Industry

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“…The availability of alternative fungicides is important because resistance conferred by the G143A mutation characteristically cannot be mitigated using higher, off-label application rates of QoI compounds in the field (Bartlett et al 2002;Fernández-Ortuño et al 2012;Kim et al 2003;Lesniak et al 2011). Additionally, this mutation was shown to be stable in C. acutatum populations and did not result in a fitness penalty in laboratory assays (Forcelini et al 2018). In our study, QoI-resistant and -sensitive isolates were similarly pathogenic but disease severity and mortality after inoculation with resistant isolates were higher than for QoI-sensitive isolates.…”

Section: Discussionmentioning

confidence: 99%

Natamycin, a New Biofungicide for Managing Crown Rot of Strawberry Caused by QoI-Resistant Colletotrichum acutatum

et al. 2018

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Anthracnose crown rot of strawberry, caused by Colletotrichum acutatum, is an important disease affecting California nursery and fruit production. Preplant dip treatments of transplants with fludioxonil-cyprodinil or azoxystrobin are industry standards for managing the disease and have been used extensively. Following reports of reduced efficacy of azoxystrobin in the field, high levels of quinone outside inhibitor (QoI) resistance were detected in California isolates of the pathogen. Resistance was associated with the G143A mutation in the cytochrome b gene, similar to a previous report from Florida, and there were no detected fitness penalties in pathogenicity or virulence. Therefore, several alternative fungicides were investigated in laboratory and field studies. Subsequently, the new biofungicide natamycin was identified. Baseline sensitivities of 74 isolates of C. acutatum to natamycin were determined to be unimodal, with a range from 0.526 to 1.996 μg/ml (mean 0.973 μg/ml). Although this toxicity was considerably lower than that of azoxystrobin (using sensitive isolates), fludioxonil, or cyprodinil, dip treatments of transplants with natamycin (at 500 or 1000 mg/liter) were highly effective. Disease severity and plant mortality in field studies with inoculated transplants were reduced to similarly low levels as treatments containing fludioxonil, whereas azoxystrobin failed in inoculations with QoI-resistant isolates of C. acutatum. Fruit yield was also significantly increased by natamycin as compared with the inoculated control. Differences in disease susceptibility were observed among cultivars evaluated, with Monterey and Portola more susceptible than Fronteras. Natamycin has a unique mode of action that is different from other fungicides registered on strawberry and, based on this research, was registered in the United States as a preplant, biofungicide dip treatment of strawberry transplants for management of anthracnose crown rot.

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Fitness, Competitive Ability, and Mutation Stability of Isolates of Colletotrichum acutatum from Strawberry Resistant to QoI Fungicides

Cited by 52 publications

References 35 publications

Latent postharvest pathogens of pome fruit and their management: from single measures to a systems intervention approach

Latent postharvest pathogens of pome fruit and their management: from single measures to a systems intervention approach

Identification and characterization of new mutations in mitochondrial cytochrome b that confer resistance to bifenazate and acequinocyl in the spider miteTetranychus urticae

Natamycin, a New Biofungicide for Managing Crown Rot of Strawberry Caused by QoI-Resistant Colletotrichum acutatum

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