scholarly journals Resistance in Strawberry Isolates of Colletotrichum acutatum from Florida to Quinone-Outside Inhibitor Fungicides

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2050-2056 ◽  
Author(s):  
Bruna B. Forcelini ◽  
Teresa E. Seijo ◽  
Achour Amiri ◽  
Natalia A. Peres
Keyword(s):  
Amino Acid ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Effective Concentration ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Amino Acid Substitutions ◽  
Strawberry Fruit ◽  
Quinone Outside Inhibitor ◽  
Germ Tube Elongation

Anthracnose fruit rot of strawberry, caused by Colletotrichum acutatum, is a major disease in Florida and frequent quinone-outside inhibitor (QoI) fungicide applications are needed for disease control. From 1994 to 2014, 181 C. acutatum isolates were collected from multiple strawberry fields in Florida with or without QoI spray history. Sensitivity to azoxystrobin and pyraclostrobin was tested based upon mycelial growth and germ tube elongation inhibition. Mean effective concentration where growth was reduced by 50% (EC50) values for isolates collected prior to 2013 based upon mycelial growth were 0.22 and 0.013 μg/ml and upon germ tube elongation were 0.57 and 0.03 μg/ml for azoxystrobin and pyraclostrobin, respectively. Mycelial growth and germ tube elongation of 48 isolates collected in 2013 and 2014 were not inhibited with azoxystrobin at 3 μg/ml and pyraclostrobin at 0.110 μg/ml. A fungicide discriminatory dose assay indicated that 43 of the 48 isolates had EC50 values higher than 100 and 10 μg/ml for azoxystrobin and pyraclostrobin, respectively. Azoxystrobin and pyraclostrobin sprayed preventively on strawberry fruit inoculated with C. acutatum failed to control resistant isolates. Sequencing of the cytochrome b gene of sensitive and resistant isolates showed that QoI-resistant isolates contained either G143A or F129L amino acid substitutions.

scholarly journals Sensitivity of Botrytis cinerea Isolates from Conventional and Organic Strawberry Fields in Brazil to Azoxystrobin, Iprodione, Pyrimethanil, and Thiophanate-Methyl

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1803-1810 ◽  
Author(s):  
Juliana S. Baggio ◽  
Natalia A. Peres ◽  
Lilian Amorim
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Commercial Production ◽  
Effective Concentration ◽  
Fruit Rot ◽  
Strawberry Fruit ◽  
Molecular Analyses ◽  
Thiophanate Methyl ◽  
Control Disease

Botrytis fruit rot, caused by Botrytis cinerea, is one of the most important strawberry diseases worldwide, and fungicide applications are often used to manage the disease in commercial production. Isolates of B. cinerea were collected from conventional and organic strawberry fields in four Brazilian States from 2013 to 2015 and their sensitivity to the main single-site mode-of action fungicides used in Brazil was tested. Resistance to azoxystrobin, iprodione, pyrimethanil, and thiophanate-methyl was found and values for effective concentration that inhibited mycelial growth by 50% were higher than 71.9, 1.2, 5.0, and 688 µg/ml, respectively, regardless the production system. Resistance to these fungicides was observed in 87.5, 76.6, 23.4, and 92.2% of isolates from conventional fields and 31.4, 22.9, 14.3, and 51.4% of isolates from organic fields, respectively. Moreover, frequencies of isolates with multiple fungicide resistance to the four active ingredients were 20.6 and 2.8% whereas 6.3 and 27.8% were sensitive to the four fungicides for conventional and organic areas, respectively. Molecular analyses of the cytochrome b, β-tubulin, and bos1 genes revealed the presence of G143A; E198A; and I365 N/S, Q369P, or N373S mutations, respectively, in resistant isolates of B. cinerea. Field rates of fungicides sprayed preventively to inoculated strawberry fruit failed to control disease caused by the respective resistant isolates.

scholarly journals Saprophytic microorganisms with potential for biological control of Botrytis cinerea on Geraldton waxflower flowers

2001 ◽  
Vol 41 (5) ◽  
pp. 697 ◽  
Author(s):  
D. R. Beasley ◽  
D. C. Joyce ◽  
L. M. Coates ◽  
A. H. Wearing
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Conidial Germination ◽  
Pseudomonas Sp ◽  
Trichoderma Spp ◽  
Fusarium Sp ◽  
Flower Abscission ◽  
Germ Tube Elongation

Saprophytic bacteria, yeasts and filamentous fungi were isolated from Geraldton waxflower flowers and screened to identify potential antagonism towards Botrytis cinerea. Isolates from other sources (e.g. avocado) were also tested. Isolates were initially screened in vitro for inhibition of B. cinerea conidial germination, germ tube elongation and mycelial growth. The most antagonistic bacteria, yeasts and fungi were selected for further testing on detached waxflower flowers. Conidia of the pathogen were mixed with conidia or cells of the selected antagonists, co-inoculated onto waxflower flowers, and the flowers were sealed in glass jars and incubated at 20˚C. The number of days required for the pathogen to cause flower abscission was determined. The most antagonistic bacterial isolate, Pseudomonas sp. 677, significantly reduced conidial germination and retarded germ tube elongation of B. cinerea. None of the yeast or fungal isolates tested was found to significantly reduce conidial germination or retard germ tube elongation, but several significantly inhibited growth of B. cinerea. Fusarium sp., Epicoccum sp. and Trichoderma spp. were the most antagonistic of these isolates. Of the isolates tested on waxflower, Pseudomonas sp. 677 was highly antagonistic towards B. cinerea and delayed waxflower abscission by about 3 days. Trichoderma harzianum also significantly delayed flower abscission. However, as with most of the fungal antagonists used, inoculation of waxflower flowers with this isolate resulted in unsightly mycelial growth.

scholarly journals Antifungal Efficacy of Plant Oils Containing Thymol and Carvacrol in Controlling Botrytis cinerea, the Causal Agent of Grape (Vitis vinifera) GrayMould

2018 ◽  
Vol 16 (02) ◽  
pp. 15-24
Author(s):  
Zaker M ◽  
Zaker L
Keyword(s):  
Essential Oils ◽  
Botrytis Cinerea ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Plant Diseases ◽  
Plant Oils ◽  
Horticultural Products ◽  
Antifungal Efficacy ◽  
Germ Tube Elongation

The efficacy of a large number of plant extracts and essential oils in controlling plant diseases has been proven worldwide. Botrytis cinerea has attacked a wide host range causing severe loss in the field and at storage. In this study the antifungal efficacy of essential oils of three medicinal plants namely wild marjoram (Zataria multifolia), wild savory (perennial) (Satureja mutica) and savory (annual) (Satureja hortensis) possessing these compounds at three concentrations: 50, 100 and 200 ppm were evaluated in controlling the mycelial growth, spore germination and germ tube elongation of B. cinerea. All treatments except savory (annual) essential oil at 50 ppm showed significant differences with the control in inhibiting the mycelial growth as well as spore germination and germ tube elongation of B. cinerea (p=0.01). It was also noted that wild marjoram at 100 ppm and wild savory (perennial) essential oils at 200 ppm could completely (100%) inhibit the growth of the fungus. Essential oils from wild marjoram and wild savory had higher antifungal activity than annual savory. Their suitable formulations could be prepared and used as safe alternatives for controlling moulds of horticultural products during storage. The Agriculturists 2018; 16(2) 15-24

scholarly journals Present status of strawberry fruit rot diseases in New Zealand

2005 ◽  
Vol 58 ◽  
pp. 74-79 ◽  
Author(s):  
O.E. Timudo-Torrevilla ◽  
K.R. Everett ◽  
N.W. Waipara ◽  
K.S.H. Boyd-Wilson Weeds ◽  
G.I. Langford ◽  
...  
Keyword(s):  
New Zealand ◽  
Room Temperature ◽  
Integrated Management ◽  
Management Strategies ◽  
Grey Mould ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Relative Importance ◽  
Strawberry Fruit ◽  
Ripe Fruit

The New Zealand strawberry industry experiences losses due to fungal diseases that can cost up to 44 million per annum or 20 of the crop value Disease control relies almost exclusively on applications of the fungicide captan During the 2003/2004 production season grower monitoring trials investigated the relative importance of grey mould (Botrytis cinerea) anthracnose (Colletotrichum acutatum) and leak (Rhizopus spp) in causing postharvest fruit rot The average fruit rot incidence (expressed per day) was 36 22 and 16 for grey mould leak and anthracnose respectively when ripe fruit was incubated at room temperature under high humidity In two grower trials and one replicated spray trial frequent captan applications did not reduce grey mould anthracnose or leak incidence compared to an unsprayed treatment Integrated management strategies for control of strawberry fruit rot diseases are urgently required for New Zealand strawberry growers

scholarly journals Resistance to the SDHI Fungicides Boscalid, Fluopyram, Fluxapyroxad, and Penthiopyrad in Botrytis cinerea from Commercial Strawberry Fields in Spain

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1306-1313 ◽  
Author(s):  
Dolores Fernández-Ortuño ◽  
Alejandro Pérez-García ◽  
Manuel Chamorro ◽  
Eduardo de la Peña ◽  
Antonio de Vicente ◽  
...  
Keyword(s):  
Amino Acid ◽  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Growing Season ◽  
Gray Mold ◽  
Effective Concentration ◽  
Site Specific ◽  
Resistance Patterns ◽  
Succinate Dehydrogenase Inhibitors

Gray mold, caused by the necrotrophic fungus Botrytis cinerea., is one of the most economically important diseases of strawberry. Gray mold control involves the application of fungicides throughout the strawberry growing season; however, B. cinerea isolates resistant to multiple classes of site-specific fungicides have been recently reported in the Spanish gray mold population. Succinate dehydrogenase inhibitors (SDHI) constitute a relatively novel class of fungicides registered for gray mold control representing new alternatives for strawberry growers. In the present study, 37 B. cinerea isolates previously characterized for their sensitivity to boscalid and amino acid changes in the SdhB protein were used to determine the effective concentration that reduces mycelial growth by 50% (EC50) to fluopyram, fluxapyroxad, and penthiopyrad. The present study was also conducted to obtain discriminatory doses to monitor SDHI fungicide resistance in 580 B. cinerea isolates collected from 27 commercial fields in Spain during 2014, 2015, and 2016. The EC50 values ranged from 0.01 to >100 μg/ml for fluopyram, <0.01 to 4.19 μg/ml for fluxapyroxad, and, finally, <0.01 to 59.65 μg/ml for penthiopyrad. Based on these results, as well as findings from a previous publication, the discriminatory doses chosen to examine sensitivities to boscalid, fluopyram, fluxapyroxad, and penthiopyrad were 100, 15, 1, and 6 μg/ml, respectively. Over the course of the 3-year monitoring period, the overall frequencies of resistance to the four SDHI were 56.9, 6.9, 12.9, and 24.6%, respectively. The frequency of boscalid-resistant isolates decreased from 73 to 41% over the years; however, the fluopyram-resistant isolates increased from 5 to 10% after 1 year of registration. Four SDHI resistance patterns were observed in our population, which included patterns I (30%; resistance to boscalid), II (13.8%; resistance to boscalid and penthiopyrad), III (5.7%; boscalid, fluxapyroxad, and penthiopyrad), and IV (7.9%; resistance to boscalid, fluopyram, fluxapyroxad, and penthiopyrad). Patterns I and II were associated with the amino acid substitutions H272R and H272Y; pattern III was associated only with the H272Y mutation; and, finally, pattern IV was associated with the N230I allele in the SdhB subunit. For gray mold management, it is suggested that the simultaneous use of boscalid and penthiopyrad should be limited to one application per season; however, fluxapyroxad and, especially, fluopyram could be used as valid SDHI alternatives for gray mold control, although they should be applied with caution.

scholarly journals Mycelial Growth and Biological Control Measures of Botrytis cinerea Isolated from Strawberry Fruit Rot Disease in Bangladesh

2020 ◽  
Vol 8 (2) ◽  
pp. 13-18
Author(s):  
Sanjida Sultana ◽  
Md. Maniruzzaman Sikder ◽  
Md. Sabbir Ahmmed ◽  
Aireen Sultana ◽  
Nuhu Alam
Keyword(s):  
Biological Control ◽  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Control Measures ◽  
Fruit Rot ◽  
Strawberry Fruit ◽  
Rot Disease

scholarly journals Growth-inhibiting activity of citronella essential oil to multiple fungal plant pathogens

2019 ◽  
Author(s):  
Mark Angelo O. Balendres ◽  
Fe M. Dela Cueva
Keyword(s):  
Essential Oil ◽  
Growth Inhibition ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Germ Tube ◽  
Plant Pathogens ◽  
Field Experiments ◽  
Fungal Plant Pathogens ◽  
Germ Tube Elongation

AbstractCymbopogon species are among the most reported essential oils with fungitoxic effect. In this study, mycelial growth of Fusarium oxysporum (banana wilt), Colletotrichum gloeosporioides (mango anthracnose), C. falcatum (sugarcane red rot) and Neopestalotiopsis spp. (mango leaf spot) as influenced by varying concentrations of citronella essential oil (CEO) was assessed in in vitro assays. Following growth inhibition test, spore germination and germ tube elongation of C. gloeosporioides were then examined. Mycelial growth of all test fungal pathogens was strongly inhibited by CEO, but variations were observed among fungal species. This growth inhibition activity was caused by the inhibition of spore germination and germ tube elongation as observed in C. gloeosporioides. The findings of this study show the strong growth-inhibitory activity of CEO to multiple fungal pathogens, indicating CEO’s potential as a chemical control approach against these fungal pathogens. Glasshouse and field experiments would establish CEO as one potential alternative to fungicides.

scholarly journals Antifungal effect of essential oil and different extracts obtained from Nepeta meyeri on Botrytis cinerea

2021 ◽  
Vol 20 (1) ◽  
pp. 111-122
Author(s):  
Sinem Karakuş ◽  
Ökkeş Atici ◽  
Cafer Köse ◽  
Deniz Tiryaki
Keyword(s):  
Essential Oil ◽  
Botrytis Cinerea ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Rrna Gene ◽  
Potato Dextrose Agar Medium ◽  
Antifungal Effect ◽  
Petri Dishes ◽  
Germ Tube Elongation

The study concerns the antifungal effect of the aqueous and methanolic extracts, and the essential oil obtained from the aerial parts of Nepeta meyeri Benth. on Botrytis cinerea Pers. The fungus has been isolated from the infected plants of common grape Karaerik (Vitis vinifera L.) cultivating in vineyards in Üzümlü district, Erzincan (Turkey), and was cultured on potato dextrose agar medium in Petri dishes after the identification by 18S rRNA gene-based PCR assay. The concentrations of extracts from N. meyeri in Petri dishes were 2%, 5% and 10% (w/v) for aqueous extract (AE); 500, 1000 and 1500 ppm (v/v) for methanolic extract (ME), and 0.6, 0.8 and 1 µL for essential oil (EO). After the treatments, mycelial growth, spore germination, and germ tube elongation were determined. Sterile distilled water at the same ratios was used for the control treatment. Thirty-six different compounds were identified in the EO of N. meyeri by GC/MS. The highest antifungal activity has been registered for EO of N. meyeri. The inhibition rates in 1 µL/Petri of the EO were 80.72%, 18%, 38.15% on mycelial growth, spore germination and germ tube elongation, respectively. However, AE and ME of N. meyeri showed diverse effects on the studied parameters of B. cinerea. It is suggested that the favourable concentration of EO from N. meyeri can contribute to the prevention of B. cinerea infection (grey mould) which causes disease in vineyards.

scholarly journals First Report of Anthracnose Fruit Rot of Strawberry Caused by Colletotrichum acutatum in China

Plant Disease ◽  
2006 ◽  
Vol 90 (11) ◽  
pp. 1460-1460 ◽  
Author(s):  
F. M. Dai ◽  
X. J. Ren ◽  
J. P. Lu
Keyword(s):  
Relative Humidity ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Fluorescent Light ◽  
Fragaria Ananassa ◽  
Strawberry Fruit ◽  
First Report ◽  
Colony Color ◽  
Ascigerous Stage ◽  
Germ Tubes

In 2004, fruits showing dark and sunken necrotic lesions were observed on strawberries (Fragaria × ananassa Duch. cv. Mei No. 3) in a field in Shanghai, China. All isolates obtained from the infected fruits easily produced orange spore masses and developed orange colonies with orange reverse colony color; none formed setae or the ascigerous stage in culture or on the host. The conidia were hyaline, straight and fusiform, 8 to 16 × 2.5 to 4 μm, and produced melanized, ellipsoid, ball- or pear-shaped appressoria at the end of germ tubes. These isolates were similar to those described for Colletotrichum acutatum J. H. Simmonds. To confirm pathogenicity of the isolate, inoculum suspension with 4 × 106 conidia/ml was sprayed onto 10 fruiting strawberry plants until runoff. The inoculated plants were maintained at 25°C and 100% relative humidity in a growth chamber with a 12-h period of fluorescent light daily. Plants inoculated with sterilized water were controls. After 3 days, dark brown lesions appeared in the leaves, petioles, and fruits of all inoculated plants. The symptoms were similar to those observed on the strawberry fruit from which the isolate was originally isolated. The pathogen was consistently reisolated from the symptomatic fruit. No symptoms were observed on the control plants. To our knowledge, this is the first report of C. acutatum as the casual agent of anthracnose fruit rot of strawberry in China.

scholarly journals In vitro fungicide testing for control of avocado fruit rots

2007 ◽  
Vol 60 ◽  
pp. 99-103 ◽  
Author(s):  
K.R. Everett ◽  
O.E. Timudo-Torrevilla
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Effective Concentration ◽  
Colletotrichum Acutatum ◽  
Copper Hydroxide ◽  
Copper Fungicides ◽  
Avocado Fruit

Avocado fruit rots are most commonly caused by five fungi Colletotrichum acutatum C gloeosporioides Botryosphaeria parva B dothidea and Phomopsis sp These rots are controlled by applying copper fungicides in the field on eight occasions during the season Alternatives to standard copper fungicides were screened in the laboratory against these five pathogens for inhibition of spore germination and mycelial growth In total seven fungicides were tested (boscalid boscalid/pyraclostrobin three formulations of copper hydroxide copper hydroxosulphate and dithianon) The effective concentration at which 50 of spore germination or mycelial growth was inhibited (EC50) was calculated for each fungicide The EC50 values for spore germination were lowest for boscalid/pyraclostrobin and dithianon and were le;185 g/ml against all five test fungi For boscalid/pyraclostrobin all EC50 values were le;7 g/ml Copper formulations effectively inhibited spore germination by 50 at concentrations ranging from 01 g/ml to 141 g/ml but were less effective against mycelial growth

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