Pervasive fungicide resistance in <i>Botrytis</i> from strawberry in Norway: Identification of the grey mould pathogen and mutations

Nielsen, Katherine Ann Gredvig; Skårn, Magne; Brurberg, May Bente; Stensvand, Arne

doi:10.1111/ppa.13557

Cited by 11 publications

(6 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ho a focus on individual fungicides masks an underlying trend towards the develop multi-resistant (MR) strains combining within them resistance to most or even rently available fungicides (Figure 3). Similar trends towards MR strains of Bo strawberry production are being observed worldwide [25,[63][64][65].…”

Section: Overall Frequencies Of Fungicide Resistancesupporting

confidence: 78%

Fungicide Resistance in Botrytis spp. and Regional Strategies for Its Management in Northern European Strawberry Production

Weber,

Petridis

2023

BioTech

View full text Add to dashboard Cite

Grey mould, caused by Botrytis cinerea and other Botrytis spp., is a major cause of fruit rot in strawberries and other fruit crops worldwide. Repeated fungicide applications are essential in order to secure harvests. However, resistance to all currently registered single-site fungicides is widespread. The rising importance of strains with multiple resistance to most or all fungicides is of particular concern. These strains may be introduced into fields via contaminated nursery plants and/or by immigration from adjacent plots. On the basis of research conducted in northern German and Danish strawberry production, a concept to manage fungicide resistance under northern European conditions has been developed and put into regional strawberry production practice. This principally includes the testing of nursery plants for fungicide-resistant Botrytis strains prior to planting; the restricted and specific use of fungicides at flowering in the production fields, taking account of the resistance spectrum within the local Botrytis population; and crop sanitation measures such as the removal of rotting fruits at the beginning of harvest. Further options such as protected cultivation, reduced fertilisation and biological control are also discussed. The practical implementation of such a strategy in northern Germany and Denmark has been shown to reduce the occurrence of multi-resistant strains to a tolerable steady-state level.

show abstract

Section: Overall Frequencies Of Fungicide Resistancesupporting

confidence: 78%

Fungicide Resistance in Botrytis spp. and Regional Strategies for Its Management in Northern European Strawberry Production

Weber,

Petridis

2023

BioTech

View full text Add to dashboard Cite

show abstract

“…Interestingly, in all of our MDR1 or MDR1h isolates, the resistance mechanism associated with atrB overexpression coexisted with target site modifications in the same strains. The higher accumulation of target site resistances in MDR strains of the pathogen has been observed in the past in B. cinerea populations from several hosts in Germany ( Leroch et al., 2013 ) and from strawberries in the USA and Norway ( Fernandez-Ortuno et al., 2015 ; Nielsen et al., 2022 ). Thus, our results provide further evidence supporting the theory of a stepwise pattern of accumulation of resistance mutations in B. cinerea populations ( Li et al., 2014 ).…”

Section: Discussionmentioning

confidence: 91%

Multiple and multidrug resistance in Botrytis cinerea: molecular mechanisms of MLR/MDR strains in Greece and effects of co-existence of different resistance mechanisms on fungicide sensitivity

Sofianos,

Samaras,

Karaoglanidis

2023

Front. Plant Sci.

View full text Add to dashboard Cite

Botrytis cinerea is a high-risk pathogen for fungicide resistance development. Within the fungal populations, strains have developed multiple mutations in different target genes leading to multiple resistance (MLR) or mutations associated with overexpression of efflux transporters leading to multidrug resistance (MDR). These types of resistance are a major threat, and their successful management is a major challenge. The current study was initiated to a) determine frequencies of MLR/MDR strains in populations originating from several crops, b) identify the types of MDR that occur in Greece, and c) determine interactions between MLR and MDR at the level of sensitivity to botryticides. The frequencies of MLR/MDR phenotypes were determined in 515 isolates subjected to bioassays using discriminatory concentrations of thiophanate-methyl, iprodione, cyprodinil, fenhexamid, boscalid, fluopyram, fludioxonil, pyraclostrobin, and tolnaftate. Interestingly, 7.8% and 31.3% of isolates from strawberry and rootstock seedlings were resistant to every single fungicide class, while MDR phenotypes from strawberries, rootstocks, and tomatoes accounted for 26%, 87%, and 13.4%, respectively. The MLR and MDR isolates were further molecularly analyzed regarding genes erg27, sdhB, Bcpos5, and Mrr1, responsible for resistance to fenhexamid, boscalid and fluopyram, cyprodinil, and MDR, respectively. The different mutations’ presence was determined along with a new mutation in Mrr1 leading to MDR. MDR isolates were characterized as MDR1 or MDR1h based on the presence of a 3-bp deletion in Mrr1. MDR1h was predominant in isolates from rootstocks and MDR1 from tomatoes and strawberries, whereas the most frequent target-site mutations were F412S (erg27), H272R (sdhB), and L412F (Bcpos5). To determine whether the accumulation of target-site mutations along with MDR mutations exhibits an additive effect concerning fungicide resistance, the sensitivity of isolates possessing the predominant target-site mutations was calculated in both the presence and the absence of MDR-associated mutations. EC50 in cyprodinil and boscalid increased to about twofold in the presence of MDR mutations, while there was no difference for fenhexamid. In conclusion, MLR/MDR frequencies are notably high in heavily treated crops in Greece, and the combination of MLR and MDR mutations leads to even higher fungicide resistance levels, highlighting the importance of resistance management.

show abstract

“…Botrytis' high genetic variability has also contributed to its adeptness at developing resistance to fungicides. Planting material is known to harbour latent Botrytis infections, and the results from this study provide yet another example of how fungicide-resistant Botrytis is distributed and enters production systems in this manner (Nielsen et al, 2022;Oliveira et al, 2017;Weber & Entrop, 2017). Nurseries are known to use multiple sprays of products containing pyraclostrobin with boscalid and cyprodinil with fludioxonil in strawberry transplant production (Weber & Entrop, 2017), and the high frequency of fungicide resistance favours selection of resistant strains of Botrytis spp.…”

Section: Discussionmentioning

confidence: 92%

“…The four isolates included were identified as Botrytis group S (96/16-16.4 and 96/16-19.10, referred to as BS1 and BS2), one B. cinerea sensu stricto (96/16-15.3, referred to as Bc), and one B. pseudocinerea (96/16-18.5, referred to as Bp). The isolates were characterized and examined for the presence of fungicide resistance-conferring mutations in a previous study (Nielsen et al, 2022). The BS1, BS2 and Bc isolates had been stored as conidia suspensions in a 20% glycerol solution at -20 °C, and the Bp isolate had been stored as dry sclerotia at -80 °C.…”

Section: Effect Of Steam Thermotherapy On Plant Growth and Yieldmentioning

confidence: 99%

See 1 more Smart Citation

Steam thermotherapy strongly reduces Botrytis in strawberry transplants with no or minor negative effects on plant growth and yield

Gahatraj

Nielsen

et al. 2023

Eur J Plant Pathol

Self Cite

View full text Add to dashboard Cite

The effect of steam thermotherapy on Botrytis spp. populations in strawberry transplants was evaluated. Tray plants rooted in 0.2 L peat plugs of seasonal flowering cvs. Falco, Sonsation, and Soprano, and everbearing cvs. Favori and Murano were pre-treated with steam at 37 °C for 1 h, followed by 1 h at ambient temperature and air humidity, and then 2 or 4 h steam treatment at 44 °C. Except for one cultivar with a slight reduction in yield, there were no negative effects on plant performance. Compared to untreated transplants, mean incidence of Botrytis on the five cultivars was reduced by 43 and 86% with the 2 and 4 h treatments, respectively. Within cultivars the reduction was significant in 2 and 3 experiments following the 2 and 4 h treatments, respectively. Sclerotia from four different isolates of Botrytis were subjected to treatment including 4 h of steam thermotherapy and subsequently tested for viability. Following 14 days of incubation, 90 to 100% (mean 97%) of treated sclerotia failed to produce mycelial growth compared with untreated sclerotia, which all germinated and produced mycelia. Botrytis isolates recovered from both treated and untreated strawberry transplants were tested for resistance to seven fungicides, including boscalid, fenhexamid, fludioxonil, fluopyram, pyraclostrobin, pyrimethanil and thiophanate-methyl. Multiple fungicide resistance was common; 35.5% of isolates were resistant to fungicides from at least three FRAC groups. Results indicate that steam thermotherapy treatment strongly reduces populations of Botrytis spp., including fungicide-resistant strains, in strawberry transplants with negligible negative impacts on the transplants.

show abstract

Pervasive fungicide resistance in Botrytis from strawberry in Norway: Identification of the grey mould pathogen and mutations

Cited by 11 publications

References 48 publications

Fungicide Resistance in Botrytis spp. and Regional Strategies for Its Management in Northern European Strawberry Production

Fungicide Resistance in Botrytis spp. and Regional Strategies for Its Management in Northern European Strawberry Production

Multiple and multidrug resistance in Botrytis cinerea: molecular mechanisms of MLR/MDR strains in Greece and effects of co-existence of different resistance mechanisms on fungicide sensitivity

Steam thermotherapy strongly reduces Botrytis in strawberry transplants with no or minor negative effects on plant growth and yield

Contact Info

Product

Resources

About