scholarly journals Alternative control of post-harvest diseases in Tainung 1 papaya

2018 ◽  
Vol 48 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Andréa Mirne de Macêdo Dantas ◽  
Selma Rogéria de Carvalho Nascimento ◽  
Beatriz Letícia Silva da Cruz ◽  
Fernando Henrique Alves da Silva ◽  
Márcia Michelle de Queiroz Ambrósio ◽  
...  

ABSTRACT Controlling post-harvest papaya diseases without using agrochemicals is a challenge for producers. This study aimed at evaluating the effect of clove essential oil, biological fungicide (Trichodermil®), resistance inducer (Cob Sistem®) and chemical fungicide (Imazacure®) on the in vitro control of phytopathogenic fungi isolates from papaya as well as on the post-harvest quality of Tainung 1 papaya. The in vitro experiment was conducted in a complete randomized design, with five fungal species x five treatments and five replications. The in vivo experiment was conducted in a complete randomized design, with five treatments x five storage times, five replications and three fruits per replication. The fruits were stored under refrigeration at 10 ± 2 ºC and 90 ± 5 % of relative humidity and evaluated at 0, 7, 14, 21 and 28 days of storage, plus two shelf life days at 25 ± 2 ºC, to simulate marketing conditions. The inhibition of mycelial growth was evaluated in the in vitro experiment, while the diseases occurrence and post-harvest quality of the fruits were evaluated in the in vivo experiment. The clove essential oil and Trichodermil® were as efficient as Imazacure® in inhibiting the mycelial growth of Alternaria sp., Colletotrichum gloeosporioides and Rhizopus sp. The treatments with clove essential oil, Trichodermil® and Imazacure® were similar in controlling the pathogens up to 21 days of storage. The treatments had no effect on the fruits soluble solid contents.

Author(s):  
Kevison Romulo da Silva França ◽  
Flavia Mota de Figueredo Alves ◽  
Tiago Silva Lima ◽  
Alda Leaby dos Santos Xavier ◽  
Plínio Tércio Medeiros de Azevedo ◽  
...  

This study evaluates the in vitro effects of Lippia gracilis essential oil on the mycelial growth of phytopathogenic fungi. Experiments were carried out using a completely randomized design to assess the effects of eight treatments. Five replicates were evaluated for each experimental group. The essential oil was incorporated into the potato dextrose culture medium and poured into Petri dishes. Treatments were comprised of different concentrations of the oil (0.0125, 0.025, 0.05, 0.1, and 0.2%), a negative control (0.0%), and two positive controls (commercial fungicides). The plates were inoculated with fungi including Colletotrichum gloeosporioides, C. musae, C. fructicola, C. asianum, Alternaria alternata, A. brassicicola, Fusarium solani, F. oxysporum f. sp. cubense, and Lasiodiplodia theobromae and were incubated for seven days at 27 ± 2°C. The following variables were measured to verify the differences observed among treatments: percentage of mycelial growth inhibition and index of mycelial growth speed. All concentrations of L. gracilis oil inhibited the mycelial growth of the fungal species evaluated. The complete inhibition was observed between concentrations of 0.0125 and 0.1%. Treatment with oil inhibited fungal growth with similar, or even greater, efficiency than commercial fungicides.. We recommend the development of in vivo tests to verify whether L. gracilis essential oil can protect against fungal disease in live plants.


Author(s):  
Tiago Silva Lima ◽  
Kevison Romulo da Silva França ◽  
Plinio Tércio Medeiros de Azevedo ◽  
Yaroslávia Ferreira Paiva ◽  
José Carlos Santos Silva ◽  
...  

Aims: This study evaluates the inhibitory potential of the clove essential oil (Syzygium aromaticum L.) on phytopathogenic fungi in vitro and on maize seeds. Study Design: The experiments comprised completely randomized designs: Seven treatments with five replicates on in vitro test; and four treatments with five replicates each, on in vivo test. Place and Duration of Study: The work was carried out at the Center for Agrifood Science and Technology of the Federal University of Campina Grande, Pombal, Brazil, from April to May 2018. Methodology: In the in vitro test, the essential oil was incorporated into the PDA (Potato-Dextrose-Agar) culture medium. The treatments comprised five concentrations of the oil (0.0125, 0.025, 0.05, 0.1, and 0.2%), a negative control (0.0%), and a positive control (Tiram). Plates were inoculated with the tested fungi, Fusarium verticillioides, Macrophomina phaseolina, and Macrophomina pseudophaseolina, then incubated for seven days at 27±2°C. The percentage of mycelial growth inhibition (PGI) and mycelial growth rate index (MGRI) were estimated. In the in vivo test, maize seeds (AG1051 hybrid) were treated with the essential oil on concentrations equal or superior to the minimum inhibitory concentration found in the in vitro test, besides the negative and positive controls. The artificial inoculation was carried out in fungi colonies for 32 hours and the seed sanity test was performed. The percentage of seeds infected by the fungus was evaluated after seven days. Results: In vitro conditions, clove oil totally inhibited the mycelial growth of F. verticillioides, M. phaseolina and M. pseudophaseolina at concentrations of 0.05, 0.1 and 0.1%, respectively. At 0.2% concentration significantly reduced the incidence of colonies of fungi M. phaseolina and M. pseudophaseolina in hybrid corn seeds AG 1051. Conclusion: The clove essential oil had a fungitoxic effect on the phytopathogens evaluated, under in vitro and in the treatment of maize seeds.


2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1831 ◽  
Author(s):  
Renata M. Sumalan ◽  
Raufdzhon Kuganov ◽  
Diana Obistioiu ◽  
Iuliana Popescu ◽  
Isidora Radulov ◽  
...  

There is an increasing interest in developing natural methods to replace the current chemicals used for maintaining postharvest quality of citrus fruits. The essential oil antifungal activity of mint (MEO), basil (BEO), and lavender (LEO) acting as the vapor-phases was tested against Penicillium digitatum. The minimum doses with fungistatic and fungicidal effect, in vitro, acting as the vapor-phases, were set up. The minimum fungicidal dose was 300 μL for BEO and 350 μL LEO, while for MEO only minimal dose with fungistatic effect was reached. The IC50 values were calculated and used (v/v) for testing preservation of lemon fruits, in close space enriched in vapor oil. For this purpose, the following two independent in vivo experiments were carried out: experiment 1, inoculated lemons with P. digitatum stored without chemical treatments 7 days, at 22 ± 2 °C, at two concentrations (C1—IC50 equivalent; C2—half of C1); and experiment 2, the non-inoculated lemons kept under the same conditions and concentrations of EO vapor served to evaluate the lemon quality properties. The results showed that antifungal protective effect was provided in the order of LEO-C1 > BEO-C1 > MEO-C1 > BEO-C2 > MEO-C2 > LEO-C2. The quality indicators like weight loss, pH, and firmness were not negatively influenced.


2020 ◽  
Vol 39 (5) ◽  
pp. 477-490
Author(s):  
Attalla Farag El-kott ◽  
Ali S. Alshehri ◽  
Heba S. Khalifa ◽  
Abd-El-karim M. Abd-Lateif ◽  
Mohammad Ali Alshehri ◽  
...  

This study investigated whether the mechanism underlying the neurotoxic effects of cadmium chloride (CdCl2) in rats involves p66Shc. This study comprised an initial in vivo experiment followed by an in vitro experiment. For the in vivo experiment, male rats were orally administered saline (vehicle) or CdCl2 (0.05 mg/kg) for 30 days. Thereafter, spatial and retention memory of rats were tested and their hippocampi were used for biochemical and molecular analyses. For the in vitro experiment, control or p66Shc-deficient hippocampal cells were treated with CdCl2 (25 µM) in the presence or absence of SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. Cadmium chloride impaired the spatial learning and retention memory of rats; depleted levels of glutathione and manganese superoxide dismutase; increased reactive oxygen species (ROS), tumor necrosis factor α, and interleukin 6; and induced nuclear factor kappa B activation. Cadmium chloride also decreased the number of pyramidal cells in the CA1 region and induced severe damage to the mitochondria and endoplasmic reticulum of cells in the hippocampi of rats. Moreover, CdCl2 increased the total unphosphorylated p66Shc, phosphorylated (Ser36) p66Shc, phosphorylated JNK, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, cytochrome c, and cleaved caspase-3. A dose–response increase in cell death, ROS, DNA damage, p66Shc, and NADPH oxidase was also observed in cultured hippocampal cells treated with CdCl2. Of note, all of these biochemical changes were attenuated by silencing p66Shc or inhibiting JNK with SP600125. In conclusion, CdCl2 induces hippocampal ROS generation and apoptosis by promoting the JNK-mediated activation of p66Shc.


2020 ◽  
Vol 56 (No. 3) ◽  
pp. 191-196
Author(s):  
Kahkashan Perveen ◽  
Najat A. Bokhari

The essential oil obtained by the hydro-distillation of the leaves of Mentha arvensis Linnaeus was evaluated for its antifungal activity against the causal agent of the Alternaria blight of tomatoes, i.e., Alternaria alternata (Fries) Keissler. The antifungal activity of the mentha essential oil was assessed both in vitro and in vivo. The chemical composition of the mentha oil was also identified by GCMS analysis. The in vitro test revealed that the maximum inhibition in the mycelial growth (93.6%) and conidia germination (90.6%) was at the highest concentration (40 µL/mL), furthermore, it was found that the inhibition of the mycelial growth and conidia germination was dose dependent. The in vivo test proved that the application of the mentha essential oil (40 µL/mL) significantly increased the plant height (84.6%), fresh weight (81.5%) and dry weight (80.0%) when compared to the untreated tomato plants. The disease incidence was 3.5 in the untreated plants, while it was 0.93 for the mentha essential oil treated plants and was 0.08 in the carbendazim treated plants. The GC-MS analysis of the mentha essential oil identified 18 compounds in total, among which the percentage of menthol was the highest (69.2%). The mentha essential oil was successful in managing the Alternaria leaf blight in the tomato plants. Therefore, it can be explored further for the development of a natural fungicide.


1995 ◽  
Vol 9 (4) ◽  
pp. 348-354 ◽  
Author(s):  
G.E.H.M. Dijkman ◽  
J. De Vries ◽  
W.L. Jongebloed ◽  
J. Arends

Fluoride-releasing composites lose fluoride very slowly over time. An interesting question is the possible change in mechanical properties related to the F release. If this happens, it might be expected that the mechanical properties of the outer surface of a fluoridating composite are affected first. The purpose of this study was to investigate in vivo and in vitro the changes in surface microhardness and surface structure of three fluoride-releasing composites and a non-F-containing control after 28 days. In the in vitro experiment, the composites were stored in tap water at 37°C. The results show that all composites stored in water were significantly softened after 28 days. In vivo, however, a very different picture emerged: The surface microhardness of the fluoride-releasing composites did not change significantly. In vitro, the data indicate that the amount of softening of the fluoridating composites is related to the amount of fluoride released. No relation was found between the amount of F released in one month in vitro and the microhardness changes in vivo. SEM micrographs of fluoridating composites do not reflect the microhardness changes mentioned.


2021 ◽  
Vol 10 (4) ◽  
pp. e22110413826
Author(s):  
Keicy Sandy Silvestre de Souza ◽  
Anna Christina de Almeida ◽  
Stephanie Pedrosa de Oliveira ◽  
Igor Viana Brandi ◽  
Sérgio Henrique Sousa Santos ◽  
...  

Previous studies have shown that the clove essential oil concentration of 200 mg/kg did not present toxicity and histopathological changes in the liver. Based on the evidence presented in this  study, we decided to evaluate in vivo the ability of a previously developed fermented dairy beverage, tested only in vitro, in which the standard chemical preservative, potassium sorbate, was replaced by clove essential oil (2 μl/ml), to be a functional food. To this end, twenty-four male Swiss mice were divided into three groups and submitted insulin sensitivity (IST) and glucose tolerance (GTT) testing, evaluation of physiological and biochemical parameters, histopathological analysis and quantification of the expression of anti-inflammatory and pro-inflammatory cytokines in the liver, after administering daily of the fermented dairy beverage with or without clove essential oil by gavage during 30 days. The group that received the fermented dairy beverage with clove essential oil showed a lower glycemic level in GTT, a higher sensitivity to insulin and a higher glucose decay constant rate (Kitt), with relation to the other groups. In the evaluation of physiological parameters there were no signs of toxicity in the mice during the experimental period. The biochemical parameters, histopathological analysis and expression of anti-inflammatory (IL-10) and pro-inflammatory (IL1β, IL6 e TNFα) cytokines in the liver of the mice, was not significantly affected by the treatment. These results corroborated by bioinformatics analysis demonstrate that the fermented dairy beverage with clove essential oil it can function as a substitute for conventional chemical preservatives and reduce glycemic levels.


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