scholarly journals Resistance of Botrytis cinerea to Multiple Fungicides in Northern German Small-Fruit Production

Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1263-1269 ◽  
Author(s):  
Roland W. S. Weber

During the vegetation period 2010, 353 isolates of Botrytis cinerea from 23 Northern German strawberry, raspberry, highbush blueberry, and redcurrant fields were examined for sensitivity to the benzimidazole derivative thiophanate-methyl and the dicarboximide iprodione, as well as five fungicides currently used against gray mold in Germany. Of all isolates, 40.5% were highly resistant to thiophanate-methyl, 64.0% to iprodione, 45.0% to fenhexamid, 76.8% to trifloxystrobin, 21.5% to boscalid, and 14.7% to cyprodinil. No high resistance to fludioxonil was observed but medium resistance was recorded to fludioxonil as well as cyprodinil (41.1 and 27.2% of all isolates, respectively). In all, 63 isolates were sensitive to all five of the currently registered botryticides whereas 43, 81, 94, 49, and 23 isolates were medium or highly resistant to one, two, three, four, and five fungicides, respectively. Isolates resistant to five fungicides in vitro were capable of causing fruit rot on wounded apple pretreated with any one of the three commercially available products containing fenhexamid, pyraclostrobin plus boscalid, or cyprodinil plus fludioxonil. These results question the sustainability of the current gray mold control strategy relying exclusively on fungicides with specific, single-site modes of action.

2017 ◽  
Vol 107 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Wayne M. Jurick ◽  
Otilia Macarisin ◽  
Verneta L. Gaskins ◽  
Eunhee Park ◽  
Jiujiang Yu ◽  
...  

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, and ornamentals. Fludioxonil-sensitive B. cinerea isolates were collected in 2011 and 2013 from commercial storage in Pennsylvania. Eight isolates had values for effective concentrations for inhibiting 50% of mycelial growth of 0.0004 to 0.0038 μg/ml for fludioxonil and were dual resistant to pyrimethanil and thiabendazole. Resistance was generated in vitro, following exposure to a sublethal dose of fludioxonil, in seven of eight dual-resistant B. cinerea isolates. Three vigorously growing B. cinerea isolates with multiresistance to postharvest fungicides were further characterized and found to be osmosensitive and retained resistance in the absence of selection pressure. A representative multiresistant B. cinerea strain caused decay on apple fruit treated with postharvest fungicides, which confirmed the in vitro results. The R632I mutation in the Mrr1 gene, associated with fludioxonil resistance in B. cinerea, was not detected in multipostharvest fungicide-resistant B. cinerea isolates, suggesting that the fungus may be using additional mechanisms to mediate resistance. Results from this study show for the first time that B. cinerea with dual resistance to pyrimethanil and thiabendazole can also rapidly develop resistance to fludioxonil, which may pose control challenges in the packinghouse environment and during long-term storage.


FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 225
Author(s):  
Miriam Machado Cunico ◽  
Celso Garcia Auer ◽  
Marlon Wesley Machado Cunico ◽  
Obdulio Gomes Miguel ◽  
Patricio Peralta Zamora ◽  
...  

 Extratos etanólicos de anestesia, Ottonia martiana Miq., foram reavaliados quanto à inibição do crescimento micelial dos fungos Cylindrocladium spathulatum (pinta-preta da erva-mate) e Botrytis cinerea (mofo-cinzento do eucalipto), por meio do planejamento fatorial. A ocorrência de decomposição de bioativos no processo de autoclavagem também foi investigada, por meio de teste de eficiência de extratos filtrados (filtro Millipore) e esterilizados (autoclave) no controle dos fitopatógenos, nas concentrações de 1, 10, 100 e 1000 ppm. Os extratos etanólicos filtrado e esterilizado inibiram o crescimento micelial dos fungos e foram mais ativos frente a B. cinerea.O extrato filtrado exibiu maior potencial antifúngico que o extrato esterilizado. O processo de esterilização por autoclavagem causou pequena decomposição dos bioativos presentes no extrato de anestesia.Palavras-chave: Anestesia; mofo-cinzento; pinta-preta. Abstract Fungitoxic potential of ethanolic extracts of anestesia in the control of phytopathogenic diseases. The antifungal potential of anestesia, Ottonia martiana Miq. was reassessed by factorial design, in vitro testing of fungal mycelial growth compared to the pathogenic isolates Cylindrocladium spathulatum, causal agent of black spot onyerba mate, and Botrytis cinerea causal agent of gray-mold on eucalypts. Occurrence of decomposition of bioactive of the autoclaving process was investigated using foliar detached test compared to the pathogens (1000 ppm). Ethanolic extracts - EBEtOH (filtered and autoclaved) inhibited the mycelial growth of C. spathulatum and B. cinerea (1000 ppm) and were more pronounced against B. cinerea (43.6 % and 68.9 %). EBEtOH filtered (0.22 µm) presented higher activity than EBEtOH autoclaved (C. spathulatum: 52.8 % and 43.6 %, B. cinerea: 68.9 % and 43.6 %), suggesting little decomposition ofbioactive after autoclaving. EBEtOH filtrate presented potential inhibition of 28 % in eucalypt leaves against B. cinerea.  Keywords: Ottonia martiana; black spot; gray-mold.


FLORESTA ◽  
2013 ◽  
Vol 43 (1) ◽  
pp. 145 ◽  
Author(s):  
José Antonio Sbravatti Junior ◽  
Celso Garcia Auer ◽  
Ida Chapaval Pimentel ◽  
Álvaro Figueredo dos Santos ◽  
Bruno Schultz

   O Eucalyptus benthamii é uma das principais espécies de eucalipto plantadas na região Sul do Brasil, por sua resistência a geadas e por seu uso na produção florestal de madeira para fins energéticos. Na produção de mudas, uma das principais doenças ocorrentes em viveiros é o mofo-cinzento, causado pelo fungo Botrytis cinerea. Uma das alternativas para o controle dessa doença é o controle biológico com fungos endofíticos, os quais podem competir com os patógenos foliares de mudas de eucalipto. O objetivo deste trabalho foi isolar os fungos endofíticos provenientes de mudas de E. benthamii, identificá-los e selecioná-los para o controle de B. cinerea. Eles foram isolados do interior de tecidos vegetais desinfectados, identificados de acordo com critérios macro e micromorfológicos e classificados a partir de testes de controle biológico in vitro. Os resultados evidenciaram o potencial antagonista dos fungos Aspergillus sp., Penicillium sp. e Trichoderma sp. Nenhum desses fungos causou lesões em mudas de E. benthamii.Palavras-chave: Mofo-cinzento; eucalipto; viveiro.AbstractIn vitro selection of endophytes for biological control of Botrytis cinerea in Eucalyptus benthamii. Eucalyptus benthamii is one of the main eucalypt species planted in Southern Brazil, due to its resistance to frost and its use in the production of forest wood for energy purposes. During the production of seedlings, the main disease occurring in forest nurseries is gray-mold caused by the fungus Botrytis cinerea. One alternative for control this disease is biological control with fungal endophytes, which can compete with the foliar pathogens of eucalypt seedlings. The objective of this study was to isolate endophytic fungi from seedlings of Eucalyptus benthamii, identify and select them for B. cinerea control. These were isolated from the interior of disinfected plant tissues, identified according to macro and micromorphological criteria, and based on tests of biological control in vitro. The results revealed the potential antagonist of Aspergillus sp., Penicillium sp. and Trichoderma sp. No fungi caused lesions in E. benthamii seedlings.Keywords: Gray-mold; eucalypt; nursery.    


1968 ◽  
Vol 48 (3) ◽  
pp. 267-272
Author(s):  
C. O. Gourley

Captan, dichlofluanid at a high and a low rate, thiram, and a mixture of captan and thiram were tested in a field trial to control gray mold fruit rot caused by Botrytis cinerea Pers. on the strawberry varieties Gorella, Midway, Redcoat and Sparkle. The mean marketable yield of the varieties was increased by dichlofluanid (low) and thiram but not by the other treatments over that of non-sprayed plots. Dichlofluanid (high) gave better control of pre-harvest fruit rot than captan. Dichlofluanid (high) significantly reduced mean fruit size. Redcoat yields were higher with the low rate than the high rate of dichlofluanid, but pre-harvest fruit rot control and fruit size did not differ with the two rates. Gorella yields and fruit size were smaller with captan + thiram than with captan or thiram. Thiram reduced fruit size on Midway. The varietal reaction to fungicides suggests that marketable yield is the most important variable in selecting a fungicide for the control of gray mold fruit rot of strawberries.


2011 ◽  
Vol 101 (12) ◽  
pp. 1433-1445 ◽  
Author(s):  
Anne-Sophie Walker ◽  
Angélique Gautier ◽  
Johann Confais ◽  
Daniel Martinho ◽  
Muriel Viaud ◽  
...  

Botrytis cinerea is a major crop pathogen infesting >220 hosts worldwide. A cryptic species has been identified in some French populations but the new species, B. pseudocinerea, has not been fully delimited and established. The aim of this study was to distinguish between the two species, using phylogenetic, biological, morphological, and ecological criteria. Multiple gene genealogies confirmed that the two species belonged to different, well-supported phylogenetic clades. None of the morphological criteria tested (spore size, germination rate, or mycelial growth) was able to discriminate between these two species. Sexual crosses between individuals from the same species and different species were carried out. Only crosses between individuals from the same species were successful. Moreover, population genetics analysis revealed a high level of diversity within each species and a lack of gene flow between them. Finally, a population survey over time showed that B. cinerea was the predominant species but that B. pseudocinerea was more abundant in spring, on floral debris. This observation could not be explained by temperature adaptation in tests carried out in vitro or by aggressiveness on tomato or bean leaves. This study clearly establishes that B. cinerea and B. pseudocinerea constitute a complex of two cryptic species living in sympatry on several hosts, including grapevine and blackberry. We propose several biological or molecular tools for unambiguous differentiation between the two species. B. pseudocinerea probably makes a negligible contribution to gray mold epidemics on grapevine. This new species has been deposited in the MycoBank international database.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9626
Author(s):  
Huiyu Hou ◽  
Xueying Zhang ◽  
Te Zhao ◽  
Lin Zhou

Background Botrytis cinerea causes serious gray mold disease in many plants. This pathogen has developed resistance to many fungicides. Thus, it has become necessary to look for new safe yet effective compounds against B. cinerea. Methods Essential oils (EOs) from 17 plant species were assayed against B. cinerea, of which Origanum vulgare essential oil (OVEO) showed strong antifungal activity, and accordingly its main components were detected by GC/MS. Further study was conducted on the effects of OVEO, carvacrol and thymol in vitro on mycelium growth and spore germination, mycelium morphology, leakages of cytoplasmic contents, mitochondrial injury and accumulation of reactive oxygen species (ROS) of B. cinerea. The control efficacies of OVEO, carvacrol and thymol on tomato gray mold were evaluated in vivo. Results Of all the 17 plant EOs tested, Cinnamomum cassia, Litsea cubeba var. formosana and O. vulgare EOs had the best inhibitory effect on B. cinerea, with 0.5 mg/mL completely inhibiting the mycelium growth of B. cinerea. Twenty-one different compounds of OVEO were identified by gas chromatography–mass spectrometry, and the main chemical components were carvacrol (89.98%), β-caryophyllene (3.34%), thymol (2.39%), α-humulene (1.38%) and 1-methyl-2-propan-2-ylbenzene isopropyl benzene (1.36%). In vitro experiment showed EC50 values of OVEO, carvacrol and thymol were 140.04, 9.09 and 21.32 μg/mL, respectively. Carvacrol and thymol completely inhibited the spore germination of B. cinerea at the concentration of 300 μg/mL while the inhibition rate of OVEO was 80.03%. EC50 of carvacrol and thymol have significantly (P < 0.05) reduced the fresh and dry weight of mycelia. The collapse and damage on B. cinerea mycelia treated with 40 μg/mL of carvacrol and thymol was examined by scanning electron microscope (SEM). Through extracellular conductivity test and fluorescence microscope observation, it was found that carvacrol and thymol led to increase the permeability of target cells, the destruction of mitochondrial membrane and ROS accumulation. In vivo conditions, 1000 μg/mL carvacrol had the best protective and therapeutic effects on tomato gray mold (77.98% and 28.04%, respectively), and the protective effect was significantly higher than that of 400 μg/mL pyrimethanil (43.15%). While the therapeutic and protective effects of 1,000 μg/mL OVEO and thymol were comparable to chemical control. Conclusions OVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by B. cinerea.


2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Hind Lahmyed ◽  
◽  
Rachid Bouharroud ◽  
Redouan Qessaoui ◽  
Abdelhadi Ajerrar ◽  
...  

The present work aims to isolate actinomycete bacteria with antagonistic abilities towards Botrytis cinerea, the causal agent of gray mold, from a soil sample collected from the rhizosphere of a healthy tomato grove. In vitro confrontation led to the isolation of 104 actinomycete isolates; fifteen isolates have shown the most significant mortality rate of the mycelial growth of B. cinerea (>50%). Based on the results of this screening, representative strains were selected to verify their in vivo antagonistic activity on tomato fruits; the reduction of B. cinerea has a percentage ranging from 52.38% to 96.19%. Furthermore, the actinomycete isolates were evaluated for their plant growth-promoting (PGP) properties and their ability to produce biocontrol-related extracellular enzymes viz., amylase, protease, cellulase, chitinase, esterases, and lecithinase. Indeed, Ac70 showed high β-1,3-glucanase activity and siderophore production (17U/ml and 43% respectively), and the highest chitinase activity (39μmol/ml) was observed for Ac24. These results indicated that these actinomycetes might potentially control gray mold caused by B. cinerea on tomato fruits. Investigations on enhancing the efficacy and survival of the biocontrol agent in planta and finding out the best formulation are recommended for future research.


Plant Disease ◽  
2020 ◽  
Author(s):  
Andre B Gama ◽  
Leandro Gabriel Cordova ◽  
Carolina Suguinoshita Rebello ◽  
Natalia A. Peres

Blueberry is an increasingly important crop in Florida. Anthracnose fruit rot (AFR), mostly caused by Colletotrichum gloeosporioides, is favored by long wetness periods and temperatures from 15 to 27oC. Currently, the model in the Strawberry Advisory System (StAS) guides fungicide applications targeting strawberry AFR. Given the similarity between blueberry and strawberry AFR, we hypothesized that the model used in StAS could be used in a decision-support system built for blueberry AFR. There is no information on inhibition posed by fungicides on C. gloeosporioides isolates from blueberry. Our objectives were to demonstrate that the model used in the StAS could be used for blueberry AFR management in Florida, and to assess the sensitivity of isolates to fungicides. Four trials were undertaken in blueberry fields in Florida during two seasons to compare the effectiveness of fungicide applications following the model to the growers’ standard calendar. Sensitivity of blueberry C. gloeosporioides isolates to azoxystrobin, benzovindiflupyr, penthiopyrad, pydiflumetofen, boscalid, thiophanate-methyl, fluazinam, and fludioxonil was evaluated. AFR incidence and yield were compared between treatments. Following recommendations from the model resulted in disease control as effective as the standard program and in some cases with a reduced number of applications. All isolates were sensitive to benzovindiflupyr, penthiopyrad, fluazinam, and fludioxonil. Low frequency of in vitro inhibition of isolates by azoxystrobin, pydiflumetofen, boscalid, and thiophanate-methyl should raise concern for fungicide resistance. Our results indicate that the model used in StAS could be used in a blueberry decision-support system to aid Florida growers to manage AFR.


Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1069-1075
Author(s):  
Hervé F. Avenot ◽  
David P. Morgan ◽  
Joel Quattrini ◽  
Themis J. Michailides

In this study, a mycelial growth assay was used to evaluate the sensitivity to thiophanate-methyl of 144 Botrytis cinerea isolates (collection A) from Californian vineyards and pistachio and pomegranate orchards. Based on the effective concentration that inhibits 50% of growth (EC50) values for mycelial growth inhibition on fungicide-amended media, 3, 28, 10, and 58% of the isolates showed sensitivity (SS; EC50 < 1 µg/ml), low resistance (LR; 1 < EC50 < 10 µg/ml), weak resistance (WR; 10 < EC50 < 50 µg/ml), and high resistance (HR; EC50 > 100 µg/ml) toward thiophanate-methyl, respectively. The LR and HR phenotypes were observed in pistachio and pomegranate orchards, even though pomegranate was not sprayed with thiophanate-methyl. Sensitivity to thiophanate-methyl of a historical collection of 257 B. cinerea isolates (collection B) isolated from pistachio orchards in 1992, 2005, and 2006 was assessed on potato dextrose agar amended with thiophanate-methyl at the discriminatory concentration of 10 µg/ml. Average percentages of thiophanate-methyl–resistant isolates were 50, 72, and 64% in the orchards in 1992, 2005, and 2006, respectively. A study of fitness components of selected thiophanate-methyl–resistant (LR, WR, and HR) and –sensitive (SS) isolates from collection A did not reveal any significant difference between them with respect to mycelial growth on fungicide-free media and pathogenicity on cultivar Crimson Seedless berries. Comparison of β-tubulin sequences from resistant and sensitive phenotypes revealed that a glutamic acid at position 198 was changed to alanine in all HR isolates and three LR isolates. The occurrence of thiophanate-methyl resistance in B. cinerea populations should be considered when designing spray programs against blossom and shoot blight of pistachio and gray mold of grape.


Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 729-732 ◽  
Author(s):  
J. A. LaMondia ◽  
S. M. Douglas

Botrytis cinerea was isolated from infected plants in six greenhouses in Connecticut. Forty-five isolates were evaluated in vitro to determine fungicide sensitivity to benzimidazole (benomyl and thiophanate-methyl) and dicarboximide fungicides (vinclozolin and iprodione). B. cinerea isolates with fungicide resistance were recovered from each greenhouse sampled. Benzimida-zole resistance was more common than dicarboximide resistance (74 to 76% versus 36 to 43%, respectively). Multiple fungicide resistance was common. Nineteen isolates were resistant to both a benzimidazole and a dicarboximide fungicide. The level (EC50) of resistance to dicer-boximides was low compared with resistance to benzimidazoles. Isolate growth rate was not correlated to fungicide sensitivity or EC50. Fungicide resistance was apparently unrelated to the patterns of fungicide use in greenhouses sampled.


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