scholarly journals Control of the Verticillium Wilt on Tomato Plants by Means of Olive Leaf Extracts Loaded on Chitosan Nanoparticles

2022 ◽  
Vol 10 (1) ◽  
pp. 136
Author(s):  
Elisabetta Mazzotta ◽  
Rita Muzzalupo ◽  
Adriana Chiappetta ◽  
Innocenzo Muzzalupo

In this research, a new ecofriendly and sustainable fungicide agent, with the ability to control Verticillium wilt, was developed. To this purpose, a green extract of olive leaf (OLE) was prepared by ultrasound-assisted extraction (UAE) and characterized in terms of polyphenol content and antioxidant activity. Then, OLE was loaded in chitosan nanoparticles (CTNPs) to combine the antifungal activity of CTNPs and phenolic compounds to obtain an important synergic effect. Nanoparticles were synthetized using the ionic gelation technique and characterized in terms of sizes, polydispersity index, Z-potential, encapsulation efficiency, and release profile. Qualitative and quantitative analyses of OLE were performed by the HPLC method. OLE-loaded CTNPs exhibited good physicochemical properties, such as a small size and positive surface charge that significantly contributed to a high antifungal efficacy against Verticillum dahliae. Therefore, their antifungal activity was evaluated in vitro, using the minimal inhibition concentration (MIC) assay in a concentration range between 0.071 and 1.41 mg/mL. Free OLE, blank CTNPs, and OLE-loaded CTNPs possessed MIC values of 0.35, 0.71, and 0.14 mg/mL, respectively. These results suggest an important synergic effect when OLE was loaded in CTNPs. Thereafter, we tested the two higher concentrations on tomato plants inoculated with V. dahliae, where no fungal growth was observed in the in vitro experiment, 0.71 and 1.41 mg/mL. Interestingly, OLE-loaded CTNPs at the higher concentration used, diminished the symptoms of Verticillium wilt in tomato plants inoculated with V. dahliae and significantly enhanced plant growth. This research offers promising results and opens the possibility to use OLE-loaded CTNPs as safe fungicides in the control strategies of Verticillium wilt at open field.

Author(s):  
Maria-Dimitra Tsolakidou ◽  
Ioannis A Stringlis ◽  
Natalia Fanega-Sleziak ◽  
Stella Papageorgiou ◽  
Antria Tsalakou ◽  
...  

Abstract Composts represent a sustainable way to suppress diseases and improve plant growth. Identification of compost-derived microbial communities enriched in the rhizosphere of plants and characterization of their traits, could facilitate the design of microbial synthetic communities (SynComs) that upon soil inoculation could yield consistent beneficial effects towards plants. Here, we characterized a collection of compost-derived bacteria, previously isolated from tomato rhizosphere, for in vitro antifungal activity against soil-borne fungal pathogens and for their potential to change growth parameters in Arabidopsis. We further assessed root-competitive traits in the dominant rhizospheric genus Bacillus. Certain isolated rhizobacteria displayed antifungal activity against the tested pathogens and affected growth of Arabidopsis, and Bacilli members possessed several enzymatic activities. Subsequently, we designed two SynComs with different composition and tested their effect on Arabidopsis and tomato growth and health. SynCom1, consisting of different bacterial genera, displayed negative effect on Arabidopsis in vitro, but promoted tomato growth in pots. SynCom2, consisting of Bacilli, didn't affect Arabidopsis growth, enhanced tomato growth and suppressed Fusarium wilt symptoms. Overall, we found selection of compost-derived microbes with beneficial properties in the rhizosphere of tomato plants, and observed that application of SynComs on poor substrates can yield reproducible plant phenotypes.


2018 ◽  
Author(s):  
Maria-Dimitra Tsolakidou ◽  
Ioannis A. Stringlis ◽  
Natalia Fanega-Sleziak ◽  
Stella Papageorgiou ◽  
Antria Tsalakou ◽  
...  

AbstractComposts represent a sustainable way to suppress diseases and improve plant growth. Identification of compost-derived microbial communities enriched in the rhizosphere of plants and characterization of their traits, could facilitate the design of microbial synthetic communities (SynComs) that upon soil inoculation could yield consistent beneficial effects towards plants. Here, we characterized a collection of compost-derived bacteria, previously isolated from tomato rhizosphere, forin vitroantifungal activity against soil-borne fungal pathogens and for their potential to change growth parameters inArabidopsis. We further assessed root-competitive traits in the dominant rhizospheric genusBacillus. Certain isolated rhizobacteria displayed antifungal activity against the tested pathogens and affected growth ofArabidopsis, and Bacilli members possessed several enzymatic activities. Subsequently, we designed two SynComs with different composition and tested their effect onArabidopsisand tomato growth and health. SynCom1, consisting of different bacterial genera, displayed negative effect onArabidopsis in vitro, but promoted tomato growth in pots. SynCom2, consisting of Bacilli, didn’t affectArabidopsisgrowth, enhanced tomato growth and suppressed Fusarium wilt symptoms. Overall, we found selection of compost-derived microbes with beneficial properties in the rhizosphere of tomato plants, and observed that application of SynComs on poor substrates can yield reproducible plant phenotypes.


INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (04) ◽  
pp. 37-41
Author(s):  
S. M Pawaskar ◽  
◽  
K. C. Sasangan

The present study was undertaken to evaluate in vitro antimicrobial activity of the successive leaf extracts of Cynodon dactylon in petroleum ether, ethyl acetate, acetone, ethanol, methanol and water, against various gram positive & gram negative bacterial strains using zone of inhibition. Both Agar well diffusion method & Agar disc diffusion method were used to evaluate the antibacterial efficacy. The microorganisms used in the test were – Escherichia coli, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B, Bacillus subtilis, Streptococcus pyogenes, Vibrio cholerac and Enterobacter aerogenes. Two fungal strains - Candida albicans and Saccharomyces cerevisiae were also tested to evaluate the antifungal potential of the said plant extract. The reference antibiotics chloramphenicol & ampicillin (antibacterial); nystatin & clotrimazole and (antifungal) were also tested against these standard microorganisms used in the assay and the results were compared with that of the plant extracts.The results of the study revealed that all the seven successive extracts of the leaf powder of Cynodon dactylon ( L.) Pers. exhibited prominent antimicrobial and antifungal activity against all microorganisms used in the study. The nonpolar extracts i.e. petroleum ether, ethyl acetate and acetone showed the most significant antibacterial and antifungal activity against all tested organisms. The petroleum ether and ethyl acetate extracts showing maximum inhibition in the range of 8 mm - 15 mm. This was closely followed by, acetone extract, which showed the inhibition in the range of 9 mm - 13 mm.


2016 ◽  
Vol 15 (3) ◽  
pp. 62-67
Author(s):  
Frederick Agem Kechia ◽  
Ngo Teke Gerald ◽  
Bathelemy Ngameni ◽  
Charles Fokunang ◽  
Jean Paul Dzoyem ◽  
...  

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.


Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 260 ◽  
Author(s):  
Luna Pollini ◽  
Rachele Rocchi ◽  
Lina Cossignani ◽  
Jordi Mañes ◽  
Dario Compagnone ◽  
...  

In recent years, agricultural and industrial residues have attracted a lot of interest in the recovery of phytochemicals used in the food, pharmaceutical, and cosmetic industries. In this paper, a study on the recovery of phenol compounds from Lycium spp. leaves is presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been used with alcoholic and hydroalcoholic solvents. Methanolic UAE was the most successful technique for extracting phenols from Lycium leaves, and we used on leaves from L. barbarum and L. chinense cultivated in Italy. The extracts were then characterized as regards to the antioxidant properties by in vitro assays and the phenol profiling by a high performance liquid chromatography-diode array detector (HPLC-DAD). Chlorogenic acid and rutin were the main phenol compounds, but considerable differences have been observed between the samples of the two Lycium species. For example, cryptochlorogenic acid was found only in L. barbarum samples, while quercetin-3-O-rutinoside-7-O-glucoside and quercetin-3-O-sophoroside-7-O-rhamnoside only in L. chinense leaves. Finally, multivariate statistical analysis techniques applied to the phenol content allowed us to differentiate samples from different Lycium spp. The results of this study confirm that the extraction is a crucial step in the analytical procedure and show that Lycium leaves represent an interesting source of antioxidant compounds, with potential use in the nutraceutical field.


2021 ◽  
Vol 9 (06) ◽  
pp. 420-427
Author(s):  
R. Neelima ◽  
◽  
B. Sujatha ◽  
N.V. Ramana ◽  
B.V. Rao ◽  
...  

In vitro evaluation of antifungal activity by disc diffusion method was carried out on leaf extracts of D.falcata, D. falcata var pubescens, V. monoicum and V. orientale and stem extracts of D. falcata, D. falcata var pubescens, V. articulatum and V.orientale using three different solvents viz., methanol, n-hexane and ethyl acetate. The antifungal activity was tested on three fungal strains include Fusarium oxysporum, Phytophthora infestans, Sclerotium rolfsii. Overall leaf extracts exerted better inhibitory activity than stem counterparts. Among all, only V. orientale was effective against the three fungal species.Compared to stem extracts, leaf extracts of D. falcata var pubescens have shown higher antifungal activity.


2021 ◽  
Author(s):  
Pamela R. Avila ◽  
Graciela Juez Castillo ◽  
Carel E. Carvajal

Abstract Fungal diseases are a current problem in agriculture causing significant losses in several crops whereby its prevention and treatment is of utmost importance. The Chitosan nanoparticles (ChNPs) were evaluated for their antimicrobial activity against the phytopathogen Fusarium solani. The chitosan concentration in nanoparticles that showed antifungal activity was 2.0 µg/mL. ChNPs showed to be a potential antifungal candidate with applications in phytosanitary control. Transmission electron microscopy (TEM) results showed damage to the fungal cell wall and membrane caused by the nanoparticles interaction with these structures affecting fungal growth and development in in vitro as in in vivo assay where microscopy demonstrated the internalization of nanoparticles aggregates within plant root cells cytoplasm up to 45 days. Therefore ChNPs nanoparticles could be an alternative method for diseases caused by Fusarium solani instead of chemical fungicides commonly used for treating tomato root rot.


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