Floral microbes suppress growth of Monilinia laxa with minimal effects on honey bee feeding

Plant Disease ◽  
2021 ◽  
Author(s):  
Amber Crowley-Gall ◽  
Florent Trouillas ◽  
Elina L Nino ◽  
Robert N Schaeffer ◽  
Mohamed Taieb Nouri ◽  
...  
Keyword(s):  
Honey Bee ◽  
Brown Rot ◽  
Prunus Dulcis ◽  
Dual Culture ◽  
Monilinia Laxa ◽  
Beneficial Arthropods ◽  
Pollinator Attraction ◽  
Chemical Fungicides ◽  
Target Effects

Current management of Monilinia laxa, the causal agent of brown rot blossom blight in almond (Prunus dulcis) relies heavily on the use of chemical fungicides during bloom. However, chemical fungicides can have non-target effects on beneficial arthropods, including pollinators, and select for resistance in the pathogen of concern. Almond yield is heavily reliant on successful pollination by healthy honey bees (Apis mellifera); thus, identifying sustainable, effective, and pollinator-friendly control methods for blossom blight during bloom is desirable. Flower-inhabiting microbes could provide a natural, sustainable form of biocontrol for M. laxa, while potentially minimizing costly non-target effects on almond pollinators and the services they provide. As pollinators are sensitive to floral microbes and their associated taste and scent cues, assessing effects of prospective biocontrol species on pollinator attraction is also necessary. Here, our objective was to isolate and identify potential biocontrol microbes from an array of agricultural and natural flowering hosts and test their efficacy in suppressing M. laxa growth in culture. Out of an initial 287 bacterial and fungal isolates identified, fifty-six were screened using a dual culture plate assay. Most strains reduced M. laxa growth in-vitro. Ten particularly effective candidate microbes were further screened for their effect on honey bee feeding. Of the ten, nine were found to both strongly suppress M. laxa growth in culture and not reduce honey bee feeding. These promising results suggest a number of strong candidates for augmentative microbial biocontrol of brown rot blossom blight in almond with potentially minimal effects on honey bee pollination.

scholarly journals In vitro Evaluation of Botanical Extracts, Chemical Fungicides and Trichoderma harzianum Against Alternaria brassicicola Causing Leafspot of Cabbage

2020 ◽  
Vol 14 (1) ◽  
pp. 68-76
Author(s):  
Lok Bahadur Pun ◽  
Kamal Chhetri ◽  
Anju Pandey ◽  
Rajan Poudel
Keyword(s):  
Trichoderma Harzianum ◽  
Fungal Growth ◽  
Control Agent ◽  
Culture Technique ◽  
Alternaria Brassicicola ◽  
Dual Culture ◽  
Sweet Flag ◽  
Botanical Extracts ◽  
Chemical Fungicides

Alternaria leaf spot caused by Alternaria brassicicola is one of the destructive diseases of crucifers and causes considerable loss in the yield and quality of the produce. An experiment was conducted in in vitro to evaluate the efficacy of six botanical extracts at three concentrations i.e. 5%, 10% and 15%, six chemical fungicides at five different concentrations i.e. 50ppm, 100ppm, 250ppm, 500ppm and 1000ppm and Trichoderma harzianum against Alternaria brassicicola. The study was carried out using poisoned food technique for botanical extracts and chemical fungicides and dual culture technique for T. harzianum in Completely Randomized Design (CRD). Among botanical extracts, maximum inhibition (99.91%) of mycelial growth was observed in sweet flag at 15% concentration followed by 10% sweet flag (96.68%) and 5% sweet flag (93.64%) and minimum inhibition percent (5.61%) was observed in Lantana camara at 5% concentration. Hexaconazole proved to be the most effective chemical fungicide recording 100% growth inhibition at all the tested concentrations which was at par with1000 ppm metalaxyl + mancozeb (Kriloxyl Gold), 500 and 1000 ppm mancozeb and 1000 ppm carbendazim + mancozeb(SAAF)whereas, 50 ppm carbendazim was least effective in reducing fungal growth (7.16%). T. harzianum showed 65.02% inhibition of test fungus. The study indicated better performance of some chemical fungicides even at lower concentrations i.e. 100ppm and 250ppm. So, such effective fungicides could be used to minimize hazardous effect. Significant effect of some botanical extracts against pathogen growth suggests their application as potential control agent alternative to chemicals.

scholarly journals Fungicidal Activity of Plant Volatile Compounds for Controlling Monilinia laxa in Stone Fruit

Plant Disease ◽  
2007 ◽  
Vol 91 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Fiorella Neri ◽  
Marta Mari ◽  
Stefano Brigati ◽  
Paolo Bertolini
Keyword(s):  
Volatile Compounds ◽  
Mycelial Growth ◽  
Fungicidal Activity ◽  
Brown Rot ◽  
Conidial Germination ◽  
Stone Fruit ◽  
Monilinia Laxa ◽  
Plant Volatile ◽  
Plant Volatile Compounds

Nine plant-volatile compounds were tested for their activity against Monilinia laxa, the cause of brown rot in stone fruit. In vitro trials on conidial germination and mycelial growth showed a consistent fungicidal activity of trans-2-hexenal, carvacrol, and citral, whereas trans-cinnamaldehyde, hexanal, (-)-carvone, eugenol, 2-nonanone, and p-anisaldehyde exhibited a progressively lower inhibition. The best inhibitor of conidial germination was trans-2-hexenal (effective dose for 50 and 90% inhibition [ED50 and ED95] = 7.53 and 9.4 μl/liter, respectively; minimal inhibitory concentration [MIC] = 12.3 μl/liter], whereas carvacrol was the best inhibitor of mycelial growth (ED50 and ED95 = 2 and 3.4 μl/liter, respectively; MIC = 6.1 μl/liter). The three most active compounds in in vitro studies also were tested in vivo as postharvest biofumigants. The best control of brown rot was with trans-2-hexenal (efficacy ranging from 46.2 to 80.3%, depending on cultivar), whereas citral and carvacrol resulted in a lower efficacy of 40 and 32.9%, respectively. Fumigation with trans-2-hexenal at concentrations that stopped decay did not cause any visible disorders to plum, whereas it was phytotoxic to apricot, peach, and nectarine and produced off-odors or off-flavors in all species of stone fruit tested.

scholarly journals In vitro sensitivity of Monilinia laxa to fungicides approved in integrated and organic production systems

2011 ◽  
Vol 17 (4-5) ◽  
Author(s):  
I. J. Holb ◽  
M. Fazekas ◽  
F. Abonyi
Keyword(s):  
Production Systems ◽  
Sour Cherry ◽  
Brown Rot ◽  
Organic Production ◽  
Monilinia Laxa ◽  
Active Ingredients ◽  
Integrated Production ◽  
Growth Capacity ◽  
In Vitro Sensitivity

The aim of this study was to test the in vitro sensitivity of two isolates of Monilinia laxa to fungicides approved in integrated and organic production systems. In vitro efficacy of 7 fungicides (Champion 50 WP, Kocide 2000, Nordox 75 WG, Olajos rézkén, Kumulus S, Rézkén, Rézoxiklorid) and another 6 fungicides (Score 25 EC, Efuzin 500 SC, Systane, Folicur Solo, Zato Plusz, Rovral) approved in organic and integrated production systems, respectively, were tested against brown rot of sour cherry. The three isolates showed differences in sensitivity to fungicides. Fungicides (with active ingredients of copper and sulphur) applied in organic production showed relatively high percent growth capacity of M. laxa. Rézkén and Kocide 2000 showed the highest and Kumilus S the lowest efficacy against brown rot. Fungicides applied in integrated production showed relatively low percent growth capacity of M. laxa. Score 25 EC showed the lowest and Rovral and Folicur solso the highest efficacy against M. laxa.

scholarly journals Peracetic Acid and Chlorine Dioxide for Postharvest Control of Monilinia laxa in Stone Fruits

Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 773-776 ◽  
Author(s):  
M. Mari ◽  
T. Cembali ◽  
E. Baraldi ◽  
L. Casalini
Keyword(s):  
Chlorine Dioxide ◽  
Peracetic Acid ◽  
Brown Rot ◽  
In Vitro Tests ◽  
Monilinia Laxa ◽  
Stone Fruits ◽  
Duration Of Treatment ◽  
Chemical Product ◽  
Postharvest Control

The effects of different concentrations of peracetic acid (PAA; 62.5, 125, 250, 500, and 1,000 μg/ml)and chlorine dioxide (ClO2; 12.5, 25, 50, 100, and 200 μg/ml) on germination of Monilinia laxa conidia were tested. Conidia germination was related to the concentration of chemical product used, as well as duration of treatment. Complete inhibition of germination was observed with PAA at 500 μg/ml after 5 min of contact with conidia and with ClO2 at 50 μg/ml after 1 min of contact with conidia. The results of in vitro tests were confirmed by inoculation of fruits with treated conidia. The PAA treatment also was effective 1 h after pathogen inoculation but only on plums, for which a 1,000 μg/ml treatment significantly reduced decay incidence by 50%. In a semi-commercial test, pathogen conidia dipped for 20 min in PAA at 250 μg/ml or ClO2 at 10 μg/ml or for 5 min in PAA at 250 μg/ml were completely inhibited, and no brown rot was observed in inoculated wounded nectarines and plums.

scholarly journals Pectin as Carbon Source for Monilinia laxa Exoproteome and Expression Profiles of Related Genes

2020 ◽  
Vol 33 (9) ◽  
pp. 1116-1128 ◽  
Author(s):  
Silvia Rodríguez-Pires ◽  
Paloma Melgarejo ◽  
Antonieta De Cal ◽  
Eduardo A. Espeso
Keyword(s):  
Extracellular Enzymes ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Carbon Sources ◽  
Brown Rot ◽  
Secretory Activity ◽  
Late Response ◽  
Monilinia Laxa ◽  
Brown Rot Fungi

Pectin, as part of the fruit cell wall, can be degraded by brown rot fungi by coordinating the production, secretion, and action of extracellular enzymes. In this study, pectin utilization by the necrotroph Monilinia laxa 8L was studied by in vitro and in silico approaches. A total of 403 genes encoding carbohydrate-active enzymes (CAZymes) were identified, including 38 coding a predicted pectin-degrading activity. Analyzing the differences between M. laxa 8L exoproteomes in media containing glucose and pectin as sole carbon sources, we identified 107 pectin-specific proteins, among them, 64.48% harbor a classical secretory activity, including 42 CAZymes and six pectin-degrading proteins. Analyzing the gene-expression patterns of some pectinase families revealed their possible sequential action in pectin disassembly. We found, in vitro, an early pectin-dependent induction of MlRGAE1, MlPG1, and three members of the rhamnosidase family (MlαRHA2, MlαRHA3, and MlαRHA6) and late response of MlPG2 and MlPNL3. M. laxa 8L has the ability to use both pectin and byproducts as carbon sources, based on a functional pectinolytic machinery encoded in its genome, subjected to pectin-dependent regulation and appropriate secretion mechanisms of these pectinolytic enzymes. Differences in the secretion and transcription profile of M. laxa 8L provided insights into the different mechanisms that contribute to brown rot development.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

scholarly journals Botanical Control of Citrus Green Mold and Peach Brown Rot on Fruits Assays Using a Persicaria acuminata Phytochemically Characterized Extract

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 425
Author(s):  
Melina G. Di Liberto ◽  
Gisela M. Seimandi ◽  
Laura N. Fernández ◽  
Verónica E. Ruiz ◽  
Laura A. Svetaz ◽  
...  
Keyword(s):  
Ecological Model ◽  
Fungal Infections ◽  
Ex Vivo ◽  
Central Area ◽  
Brown Rot ◽  
Phytopathogenic Fungi ◽  
Perennial Herb ◽  
Huh7 Cells ◽  
Gas Chromatography Mass Spectroscopy

Persicaria acuminata (Polygonaceae) is a perennial herb that grows in the central area of Argentina and it is commonly used by native populations to heal infected wounds and other conditions related to fungal infections. In this article, we explored the in vitro antifungal activity of its ethyl acetate extract against a panel of three fruit phytopathogenic fungi including: Penicillium digitatum, P. italicum, and Monilinia fructicola. The sesquiterpenes isolated from the extract were also evaluated against these strains, demonstrating that the dialdehyde polygodial was the responsible for this activity. In order to encourage the use of the extract rather than the pure compound, we displayed ex vivo assays using fresh oranges and peaches inoculated with P. digitatum and M. fructicola, respectively, and subsequently treated by immersion with an extract solution of 250 and 62.5 µg/mL, respectively. There were no statistically significant differences between the treatments with commercial fungicides and the extract over the control of both fruit rots. The concentration of the active compound present in the extract used on fruit experiments was determined by Gas Chromatography-Mass Spectroscopy. Finally, cytotoxicity evaluation against Huh7 cells showed that P. acuminata extract was less cytotoxic than the commercial fungicides at the assayed concentrations. After these findings we could conclude that a chemically characterized extract of P. acuminata should be further developed to treat fungal diseases in fruits from an agro-ecological model.

scholarly journals Improving the Biocontrol Potential of Bacterial Antagonists with Salicylic Acid against Brown Rot Disease and Impact on Nectarine Fruits Quality

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Disease Severity ◽  
Mycelial Growth ◽  
Brown Rot ◽  
Antagonistic Bacteria ◽  
Biological Treatments ◽  
Rot Disease ◽  
The Impact

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.

scholarly journals Trichoderma asperellum T76-14 Released Volatile Organic Compounds against Postharvest Fruit Rot in Muskmelons (Cucumis melo) Caused by Fusarium incarnatum

2021 ◽  
Vol 7 (1) ◽  
pp. 46
Author(s):  
Warin Intana ◽  
Suchawadee Kheawleng ◽  
Anurag Sunpapao
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Cucumis Melo ◽  
Fungal Growth ◽  
Fruit Rot ◽  
Postharvest Disease ◽  
Dual Culture ◽  
Trichoderma Asperellum ◽  
Volatile Organic

Postharvest fruit rot caused by Fusarium incarnatum is a destructive postharvest disease of muskmelon (Cucumis melo). Biocontrol by antagonistic microorganisms is considered an alternative to synthetic fungicide application. The aim of this study was to investigate the mechanisms of action involved in the biocontrol of postharvest fruit rot in muskmelons by Trichoderma species. Seven Trichoderma spp. isolates were selected for in vitro testing against F. incarnatum in potato dextrose agar (PDA) by dual culture assay. In other relevant works, Trichoderma asperellum T76-14 showed a significantly higher percentage of inhibition (81%) than other isolates. Through the sealed plate method, volatile organic compounds (VOCs) emitted from T. asperellum T76-14 proved effective at inhibiting the fungal growth of F. incarnatum by 62.5%. Solid-phase microextraction GC/MS analysis revealed several VOCs emitted from T. asperellum T76-14, whereas the dominant compound was tentatively identified as phenylethyl alcohol (PEA). We have tested commercial volatile (PEA) against in vitro growth of F. incarnatum; the result showed PEA at a concentration of 1.5 mg mL−1 suppressed fungal growth with 56% inhibition. Both VOCs and PEA caused abnormal changes in the fungal mycelia. In vivo testing showed that the lesion size of muskmelons exposed to VOCs from T. asperellum T76-14 was significantly smaller than that of the control. Muskmelons exposed to VOCs from T. asperellum T76-14 showed no fruit rot after incubation at seven days compared to fruit rot in the control. This study demonstrated the ability of T. asperellum T76-14 to produce volatile antifungal compounds, showing that it can be a major mechanism involved in and responsible for the successful inhibition of F. incarnatum and control of postharvest fruit rot in muskmelons.

scholarly journals Newly Developed Self-Assembling Antioxidants as Potential Therapeutics for the Cancers

2021 ◽  
Vol 11 (2) ◽  
pp. 92 ◽  
Author(s):  
Babita Shashni ◽  
Yukio Nagasaki
Keyword(s):  
Cancer Survival ◽  
Self Assembling ◽  
Therapeutic Regime ◽  
Cancer Models ◽  
Secondary Messengers ◽  
Potential Therapeutics ◽  
Target Effects ◽  
Tempo Radical

Elevated reactive oxygen species (ROS) have been implicated as significant for cancer survival by functioning as oncogene activators and secondary messengers. Hence, the attenuation of ROS-signaling pathways in cancer by antioxidants seems a suitable therapeutic regime for targeting cancers. Low molecular weight (LMW) antioxidants such as 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO), although they are catalytically effective in vitro, exerts off-target effects in vivo due to their size, thus, limiting their clinical use. Here, we discuss the superior impacts of our TEMPO radical-conjugated self-assembling antioxidant nanoparticle (RNP) compared to the LMW counterpart in terms of pharmacokinetics, therapeutic effect, and adverse effects in various cancer models.

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