Biocontrol of Sclerotinia wilt of sunflower by Pseudomonas fluorescens and Pseudomonas putida strains

1995 ◽  
Vol 41 (8) ◽  
pp. 685-691 ◽  
Author(s):  
J. M. Expert ◽  
B. Digat
Keyword(s):  
Pseudomonas Putida ◽  
Pseudomonas Fluorescens ◽  
Sclerotinia Sclerotiorum ◽  
Field Experiments ◽  
In Vitro Tests ◽  
Significant Protection ◽  
Bacterial Strains ◽  
In Situ Tests

An increase in early injury to the roots and collar of sunflower plants caused by Sclerotinia sclerotiorum has been observed in France for several years. In vitro tests (inhibition of fungi and cyanide production by bacterial strains) and in situ tests (in nonsterile humus, in a growth chamber) were performed to screen the most efficient Pseudomonas fluorescens and Pseudomonas putida strains effective against this form of injury caused by S. sclerotiorum. Although there was no correlation between in vitro and in situ tests, a positive correlation between in situ tests and field experiments was obtained. At least 1 × 106 bacteria per seed were required for significant protection in in situ tests and field trials demonstrated that significant protection of sunflower was obtained by seed bacterization with selections of P. fluorescens and P. putida.Key words: biological control, Pseudomonas fluorescens, Pseudomonas putida, Sclerotinia sclerotiorum, sunflower, bacterization.

Fruit Volatiles to Control Postharvest Rot of Stone Fruits and Pears

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 469a-469
Author(s):  
L.J. Skog ◽  
D.P. Murr ◽  
B.E. Digweed
Keyword(s):  
Volatile Compounds ◽  
Isoamyl Acetate ◽  
Penicillium Expansum ◽  
Effective Control ◽  
In Vitro Tests ◽  
Stone Fruits ◽  
In Situ Tests ◽  
Highly Effective ◽  
Postharvest Rot

Volatile compounds are ubiquitous in plants, giving fruits their characteristic aroma and flavor. There is increasing evidence that these compounds can protect plants from pathogenic organisms. In this trial ≈25 volatile compounds were tested for efficacy against Monilinia fructicola and Penicillium expansum. Both in vitro tests on agar plugs of actively growing pathogens and in situ tests on inoculated stone fruits and pears were conducted. The volatile compounds were grouped into three categories based upon fungicidal activity in vitro: highly effective (fungicidal concentration ≤100 M), moderately effective (fungicidal concentration between 100–200 M) and ineffective (fungicidal concentration >200 M). Highly effective compounds included: acetaldehyde, citral, 2-ethyl-1-hexanol, 2,exadienal, E-2-hexenal, 4-hexen-3-one, linalool, (E,E)2,4-nonadienal, E-2-nonenal, E-3-none-2-one, salicylaldehyde, and valeraldehyde. Moderately effective compounds included: (E,Z) 2,6-nonadienal, propionaldehyde, terpinene, butyl acetate, E-cinnamaldehde, hexanal, E-2-hexen-1-ol, Z-3-hexen-1-ol and isoamyl acetate. Ineffective compounds included: butyrolactone, ethanol, ethyl acetate, and methyl acetate. Effectiveness of the compounds varied with both strain and type of microorganism tested. Concentraions required for effective control were much higher when the compounds were tested on inoculated fruit. Phytotoxicity was a problem with some compounds.

scholarly journals Alternative Control of Phragmidium rubi-idaei Infecting Two Rubus Species

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1452
Author(s):  
Raluca-Maria Pârlici ◽  
Aurel Maxim ◽  
Stefania Mirela Mang ◽  
Ippolito Camele ◽  
Lucia Mihalescu ◽  
...  
Keyword(s):  
Organic Farming ◽  
Plant Pathogens ◽  
Field Experiments ◽  
Control Sample ◽  
Field Tests ◽  
In Vitro Tests ◽  
Rust Disease ◽  
Conidia Germination ◽  
The Impact

Organic berry plantations have been gaining popularity among farmers during recent years. Even so, farmers experience serious challenges in disease control management, which is a concern in organic farming. Phragmidiumrubi-idaei (DC) P. Karst is the pathogen responsible for blackberry and raspberry rust disease, one of the most present and active diseases in plantations. The antifungal certified products found on the organic farming market offer the opportunity for an efficient control strategy over plant pathogens in fruit shrub plantations. In this study, 5 natural based products—namely Altosan, Mimox, Canelys, Zitron, and Zeolite—were tested for their fungistatic effect over P. rubi-idaei. The experiments were carried out under laboratory conditions, performing observations over the impact of organic products, used at different concentration levels, on rust conidia germination. Moreover, field experiments were conducted in order to evaluate the efficiency of different treatments for rust control on raspberry (‘Polka’, ‘Veten’ and ‘Heritage’) and blackberry (‘Thorn Free’, ‘Chester’ and ‘Loch Ness’) varieties. Data analysis based on ANOVA tests showed significant differences between the tested variants and the control sample at p < 0.001. Furthermore, LSD test confirmed differences between all substances tested (p < 0.005). The natural products Canelys (formulated with cinnamon) and Zytron (based on citrus extract) have proven the highest inhibitory capacity for conidia germination during in vitro tests registering values of 80.42% and 78.34%, respectively. The same high inhibitory rates against rust pathogen were kept also in the field tests using the same two natural-based products mentioned earlier. In addition, outcomes from this study demonstrated that Zeolite is not recommended for raspberry or blackberry rust control.

scholarly journals Effect of Hydrolysable Tannins and Anthocyanins on Recurrent Urinary Tract Infections in Nephropathic Patients: Preliminary Data

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 591 ◽  
Author(s):  
Annalisa Noce ◽  
Francesca Di Daniele ◽  
Margherita Campo ◽  
Manuela Di Lauro ◽  
Anna Pietroboni Zaitseva ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Bacterial Flora ◽  
Bioactive Compound ◽  
In Vitro Tests ◽  
Bacterial Strains ◽  
Quercetin Derivatives ◽  
Hydrolysable Tannins ◽  
Tract Infections

Urinary tract infections (UTIs) are caused by uropathogenic microorganism colonization. UTIs often require an antibiotic therapy that can cause the selection of antibiotic-resistant bacterial strains. A natural bioactive compound may represent a valid therapeutic adjuvant approach, in combination with drug therapy. In this paper, we present a pilot study, based on the administration of an oral food supplement (OFS), containing chestnut tannins and anthocyanins, to nephropathic patients suffering from recurrent UTIs (16 treated patients with 1 cp/day and 10 untreated patients). We performed laboratory tests and quality of life and body composition assessments, at T0 (baseline) and T1 (after 6 weeks OFS assumption). The analysis of OFS was performed by HPLC-DAD-MS for its content in polyphenols and by in vitro tests for its antioxidative and anti-free radical activities. In each capsule, polyphenol content was 6.21 mg (4.57 mg hydrolysable tannins, 0.94 mg anthocyanosides, 0.51 mg proanthocyanidins, 0.18 mg quercetin derivatives). A significant reduction of erythrocyte sedimentation rate was observed only in male patients. Urinalysis showed a significant reduction of leukocytes in both genders, whereas urinary bacterial flora at T1 significantly decreased only in male subjects. Tannins seem to exert an antimicrobial action according to gender, useful to counteract the recurrence of UTIs.

scholarly journals Rizobacterias con potencial antagonista in vitro a Mycosphaerella fijiensis Morelet

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Karen Tatiana Chávez Arteaga ◽  
Jefferson Javier Guato Molina ◽  
Jorge Luis Rodríguez Acosta ◽  
Ángel Virgilio Cedeño Moreira ◽  
Ricardo Fernando Romero Meza ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Putida ◽  
Serratia Marcescens ◽  
Pseudomonas Fluorescens ◽  
Mycosphaerella Fijiensis ◽  
Subtilis Atcc ◽  
Bacillus Subtilis Atcc ◽  
Pseudomonas Veronii ◽  
Enterobacter Asburiae

El empleo de bio-controladores en la agricultura beneficia los aspectos fisiológicos en plantas, a diferencia de la constante aplicación de pesticidas en el cultivo del banano ha ocasionado la pérdida de la sensibilidad en M. fijiensis, reduciendo la microbiota del suelo. El objetivo se enfocó en caracterizar el potencial antagónico de las PGPR en inhibición de germinación de ascósporas y desarrollo micelial de M. fijiensis. Se realizaron cultivos monospóricos de M. fijiensis e identificado por PCR. Se evaluaron los extractos celulares de Pseudomonas putida PB3-6, Klebsiella variicola BO3-4, Enterobacter asburiae BA4-19, Serratia marcescens PM3-8, Enterobacter asburiae PM3-14, Pseudomonas protegens CHA0, Pseudomonas fluorescens WCS417, Pseudomonas veronii R4 y Bacillus subtilis ATCC 5540 para sus evaluaciones antagonistas: a) Inhibición del tubo germinativo de las ascósporas al 2% y b) Desarrollo micelial al (2 y 10 %). La PCR empleado en la identificación de M. fijiensis se confirma el producto de amplificación de 1018 pb. El factor antagónico de los extractos celulares al 2 % de PM3-14 y CHA0 inhibe sobre el 80 % al desarrollo de los tubos germinativos. La inhibición al desarrollo micelial del extracto celular al 2 %, de CHA0 logró una efectividad del 54 % y las cepas (PM3-8, PM3-14 y BA4-19) con (32, 26 y 26 %). Al 10 % del extracto de la cepa PM3-8 inhibe el desarrollo micelial con niveles de turbidez de 0,47 (OD600nm). El empleo de estos bio-controladores en la agricultura ofrecerá una alternativa para beneficiar en la reducción del uso de agroquímicos

scholarly journals Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors

2019 ◽  
Vol 79 (12) ◽  
pp. 2242-2250 ◽  
Author(s):  
Miriam H. A. van Eekert ◽  
Walter T. Gibson ◽  
Belen Torondel ◽  
Faraji Abilahi ◽  
Bernard Liseki ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
In Vitro Tests ◽  
Full Potential ◽  
Water Addition ◽  
Intrinsic Factors ◽  
Pit Latrine ◽  
First Time

Abstract In vitro methods were used to assess the full potential for decomposition (measured as biogas formation) from pit latrine samples taken from the top layer of 15 Tanzanian latrines. We found considerable variability in the decomposition rate and extent. This was compared with decomposition in the same latrines, measured by comparing top layer composition with fresh stools and deeper (older) layers, to assess whether this potential was realised in situ. Results showed a close match between the extent of organic material breakdown in situ and in vitro, indicating that anaerobic digestion is the dominant pathway in latrines. The average potential decrease in chemical oxygen demand (COD) (determined as methane production in vitro within 60 days) and actual measured decrease in situ are 68.9% ± 11.3 and 69.7% ± 19.4, respectively. However in the in vitro tests, where samples were diluted in water, full decomposition was achieved in 2 months, whereas in situ it can take years; this suggests that water addition may offer a simple route to improving latrine performance. The results also allowed us to estimate, for the first time to our knowledge using experimental data, the contribution that latrines make to greenhouse gas emissions globally. This amounts to ∼2% of annual US emissions.

scholarly journals Effect of some fungicides against the growth inhibition of Sclerotinia sclerotiorum mycelial compatibility groups

2015 ◽  
Vol 55 (4) ◽  
pp. 354-361 ◽  
Author(s):  
Alireza Dalili ◽  
Saeed Bakhtiari ◽  
Hossein Barari ◽  
Majid Aldaghi
Keyword(s):  
Growth Inhibition ◽  
Sclerotinia Sclerotiorum ◽  
Integrated Management ◽  
In Vitro Tests ◽  
Sclerotinia Stem Rot ◽  
Mazandaran Province ◽  
Brassica Napus L ◽  
Northern Iran ◽  
Mycelial Compatibility

Abstract Sclerotinia sclerotiorum (Lib.) de Bary, the causal agent of Sclerotinia stem rot, is one of the most important pathogens of Brassica napus L. in northern Iran. In this study, 13 mycelial compatibility groups (MCGs) of the fungus were identified among 31 isolates sampled from four regions of Mazandaran province, Iran. Effective fungicides are useful in the integrated management of the disease. So, the effect of tebuconazole, propiconazole, cyproconazole, and Rovral-TS at five doses (0.0001, 0.001, 0.01, 0.1, and 1 ppm) was studied on the growth inhibition of S. sclerotiorum as in vitro tests. Maximum inhibition (100%) of S. sclerotiorum mycelial growth was obtained by the highest dose (1 ppm) of all tested fungicides, as well as by the doses of 0.1 and 0.01 ppm of propiconazole, cyproconazole, and tebuconazole. In this investigation, the reaction of S. sclerotiorum isolates belonging to different MCGs was evaluated against tebuconazole, propiconazole, cyproconazole, and Rovral-TS at their EC50 ranges. The results revealed that there was high variation of S. sclerotiorum MCGs against different fungicides. The inhibition percentage varied between 4.29% and 71.72%.

Fertilization biology of the abalone Haliotis laevigata: laboratory and field studies

1999 ◽  
Vol 56 (9) ◽  
pp. 1668-1678 ◽  
Author(s):  
Russ Babcock ◽  
John Keesing
Keyword(s):  
Field Experiments ◽  
Nearest Neighbor ◽  
Field Studies ◽  
Fertilization Success ◽  
Limiting Factor ◽  
Fertilization Rates ◽  
Abalone Species ◽  
Nearest Neighbor Distances

A combination of laboratory and field experiments with the commercial abalone species Haliotis laevigata showed that fertilization may be a limiting factor in some exploited populations when distances separating spawning individuals are too large. The effects of gamete age, gamete concentration, and gamete contact time in the laboratory were used to model fertilization success in situ and compared with experimental fertilization rates in the field. Highest fertilization rates in vitro (80%) were found for sperm concentrations in the range of 1 × 104 to 1 × 106·mL-1. Fertilization rates of 48 ± 1.7% (95% CI) were measured at separation distances of 2 m and dropped to 2.8 ± 0.7% (95% CI) at 16 m downstream, agreeing closely with rates predicted by the model. Recruitment failures reported for South Australian populations of H. laevigata have occurred when densities fell below ca.0.3 animals·m-2, or mean nearest-neighbor distances between 1 and 2 m. This density corresponds well to critical nearest-neighbor distances for fertilization success. Stocks at higher densities are predicted to have higher fertilization rates (ca.90%) such that fertilization success is not a factor limiting recruitment.

Effects of root inoculation and fungicide soil drenches on sclerotinia blight of coneflower

2000 ◽  
Vol 80 (4) ◽  
pp. 909-915 ◽  
Author(s):  
H. Wang ◽  
K. F. Chang ◽  
S. F. Hwang ◽  
G. D. Turnbull ◽  
R. J. Howard
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Dose Response ◽  
Root Rot ◽  
Field Experiments ◽  
Disease Incidence ◽  
Response Model ◽  
Inoculum Sources ◽  
Sclerotinia Blight ◽  
Seedling Roots

Greenhouse studies showed that root inoculation had significant effects on sclerotinia blight (Sclerotinia sclerotiorum) of coneflower (Echinacea sp.). Seedling wilt and root rot symptoms caused by S. sclerotiorum were most severe when inoculum was placed in direct contact with seedling roots, and diminished as the distance of the inoculum from the roots increased. When colonized agar disks, colonized oat grains and sclerotia as inoculum sources were evaluated on E. angustifolia, grain inoculum was the most virulent and sclerotia the least. An in vitro bioassay was conducted, and a logistic dose-response model was developed for the fungicides benomyl, vinclozolin, iprodione and dicloran. The first three fungicides were further evaluated in greenhouse experiments. Benomyl was the most effective in controlling S. sclerotiorum in both bioassay and greenhouse evaluations. The same three fungicides were evaluated in two field experiments in Alberta, where all were effective in reducing disease incidence. Key words: Echinacea sp., Sclerotinia sclerotiorum, dose-response model

scholarly journals Medicated Hydroxyapatite/Collagen Hybrid Scaffolds for Bone Regeneration and Local Antimicrobial Therapy to Prevent Bone Infections

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1090
Author(s):  
Manuela Mulazzi ◽  
Elisabetta Campodoni ◽  
Giada Bassi ◽  
Monica Montesi ◽  
Silvia Panseri ◽  
...  
Keyword(s):  
Delivery System ◽  
Local Delivery ◽  
Bone Tissue Regeneration ◽  
In Vitro Tests ◽  
Antibiotic Drugs ◽  
Antibiotic Drug ◽  
Microbial Infections ◽  
Extended Duration

Microbial infections occurring during bone surgical treatment, the cause of osteomyelitis and implant failures, are still an open challenge in orthopedics. Conventional therapies are often ineffective and associated with serious side effects due to the amount of drugs administered by systemic routes. In this study, a medicated osteoinductive and bioresorbable bone graft was designed and investigated for its ability to control antibiotic drug release in situ. This represents an ideal solution for the eradication or prevention of infection, while simultaneously repairing bone defects. Vancomycin hydrochloride and gentamicin sulfate, here considered for testing, were loaded into a previously developed and largely investigated hybrid bone-mimetic scaffold made of collagen fibers biomineralized with magnesium doped-hydroxyapatite (MgHA/Coll), which in the last ten years has widely demonstrated its effective potential in bone tissue regeneration. Here, we have explored whether it can be used as a controlled local delivery system for antibiotic drugs. An easy loading method was selected in order to be reproducible, quickly, in the operating room. The maintenance of the antibacterial efficiency of the released drugs and the biosafety of medicated scaffolds were assessed with microbiological and in vitro tests, which demonstrated that the MgHA/Coll scaffolds were safe and effective as a local delivery system for an extended duration therapy—promising results for the prevention of bone defect-related infections in orthopedic surgeries.

scholarly journals Factors Influencing In Vitro Killing of Bacteria by Hemocytes of the Eastern Oyster (Crassostrea virginica)

1999 ◽  
Vol 65 (7) ◽  
pp. 3015-3020 ◽  
Author(s):  
Fred J. Genthner ◽  
Aswani K. Volety ◽  
Leah M. Oliver ◽  
William S. Fisher
Keyword(s):  
Bactericidal Activity ◽  
Vibrio Vulnificus ◽  
Hydrolytic Enzymes ◽  
Eastern Oyster ◽  
In Vitro Tests ◽  
Wild Type ◽  
Bacterial Strains ◽  
Dye Reduction ◽  
Colonial Morphology

ABSTRACT A tetrazolium dye reduction assay was used to study factors governing the killing of bacteria by oyster hemocytes. In vitro tests were performed on bacterial strains by using hemocytes from oysters collected from the same location in winter and summer. Vibrio parahaemolyticus strains, altered in motility or colonial morphology (opaque and translucent), and Listeria monocytogenes mutants lacking catalase, superoxide dismutase, hemolysin, and phospholipase activities were examined in winter and summer. Vibrio vulnificus strains, opaque and translucent (with and without capsules), were examined only in summer. AmongV. parahaemolyticus and L. monocytogenes, significantly (P < 0.05) higher levels of killing by hemocytes were observed in summer than in winter. L. monocytogenes was more resistant than V. parahaemolyticus or V. vulnificus to the bactericidal activity of hemocytes. In winter, both translucent strains of V. parahaemolyticus showed significantly (P < 0.05) higher susceptibility to killing by hemocytes than did the wild-type opaque strain. In summer, only one of the V. parahaemolyticus translucent strains showed significantly (P < 0.05) higher susceptibility to killing by hemocytes than did the wild-type opaque strain. No significant differences (P > 0.05) in killing by hemocytes were observed between opaque (encapsulated) and translucent (nonencapsulated) pairs of V. vulnificus. Activities of 19 hydrolytic enzymes were measured in oyster hemolymph collected in winter and summer. Only one enzyme, esterase (C4), showed a seasonal difference in activity (higher in winter than in summer). These results suggest that differences existed between bacterial genera in their ability to evade killing by oyster hemocytes, that a trait(s) associated with the opaque phenotype may have enabled V. parahaemolyticus to evade killing by the oyster’s cellular defense, and that bactericidal activity of hemocytes was greater in summer than in winter.

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