scholarly journals Antagonistic potential of lactobacillus plantarum against some postharvest pathogenic fungi

2019 ◽  
pp. 79-88
Author(s):  
Svetlana Zivkovic ◽  
Stefan Stosic ◽  
Danijela Ristic ◽  
Ivan Vucurovic ◽  
Milos Stevanovic
Keyword(s):  
Lactobacillus Plantarum ◽  
Fungal Pathogens ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
In Vitro Assays ◽  
Colletotrichum Acutatum ◽  
Bacterial Suspension ◽  
Antagonistic Potential

Lactobacillus plantarum, one of the most widespread lactic acid bacte?ria, exert a strong antagonistic activity against many microorganisms. The present study was conducted to determine in vitro and in situ antagonistic potential of L. plantarum (DSM 20174) for control postharvest decay caused by phytopathogenic fungi: Aspergillus flavus, Colletotrichum acutatum, Colletotrichum gloeosporioides, and Fusarium avenaceum. The results obtained in in vitro assays showed that L. plantarum had a stronger inhibitory effect on spore germination than on mycelia growth of all tested fungi. After 3 days of incubation, the diameter of inhibition zones ranged from 11.67 mm for C. gloeosporioides to 14.67 mm for C. acutatum. The bacterial suspension of L. plantarum significantly inhibited conidial germination of all postharvest pathogens (89.62-97.61%). In situ assays showed that treatment with L. plantarum efficiently inhibited necrosis ranging from 42.54% for C. acutatum to 54.47% for A. flavus. The disease incidence in L. plantarum treated fruits was statistically significantly lower than in the positive control for all fungi tested (P<0.05). The presented data demonstrate the antagonistic potential of L. plantarum (DSM 20174) and indicate the possibility of using this bacterial strain as a biological agent to control postharvest fungal pathogens.

Control of Postharvest Fungal Pathogens by Antifungal Compounds from Penicillium expansum

2013 ◽  
Vol 76 (11) ◽  
pp. 1879-1886 ◽  
Author(s):  
WAFA ROUISSI ◽  
LUISA UGOLINI ◽  
CAMILLA MARTINI ◽  
LUCA LAZZERI ◽  
MARTA MARI
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Fungal Pathogens ◽  
Solid Phase ◽  
Petri Dish ◽  
Pathogenic Fungi ◽  
Penicillium Expansum ◽  
Colletotrichum Acutatum ◽  
Volatile Organic

The fungicidal effects of secondary metabolites produced by a strain of Penicillium expansum (R82) in culture filtrate and in a double petri dish assay were tested against one isolate each of Botrytis cinerea, Colletotrichum acutatum, and Monilinia laxa and six isolates of P. expansum, revealing inhibitory activity against every pathogen tested. The characterization of volatile organic compounds released by the R82 strain was performed by solid-phase microextraction–gas chromatographic techniques, and several compounds were detected, one of them identified as phenethyl alcohol (PEA). Synthetic PEA, tested in vitro on fungal pathogens, showed strong inhibition at a concentration of 1,230 μg/ml of airspace, and mycelium appeared more sensitive than conidia; nevertheless, at the concentration naturally emitted by the fungus (0.726 ± 0.16 μg/ml), commercial PEA did not show any antifungal activity. Therefore, a combined effect between different volatile organic compounds produced collectively by R82 can be hypothesized. This aspect suggests further investigation into the possibility of exploiting R82 as a nonchemical alternative in the control of some plant pathogenic fungi.

scholarly journals Fusarium oxysporum (F221-B) as biocontrol agent against plant pathogenic fungi in vitro and in hydroponics

2017 ◽  
Vol 53 (No. 2) ◽  
pp. 85-95 ◽  
Author(s):  
Thongkamngam Titi ◽  
Jaenaksorn Tanimnun
Keyword(s):  
Fusarium Oxysporum ◽  
Fungal Pathogens ◽  
Biocontrol Agent ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
Curvularia Lunata ◽  
Plant Growth Promoting ◽  
Healthy Control ◽  
Further Development

Efficacy of non-pathogenic Fusarium oxysporum (F221-B) was assessed as a possible biocontrol agent against fungal pathogens, namely Curvularia lunata (C11, C12), F. semitectum (F113), F. oxysporum f.sp. lactucae (F221-R, F442-G), Rhizoctonia solani (R11, R12), Rhizoctonia sp. (R111, R112, R113) in vitro, while F221-B showed a moderate ability to inhibit the mycelial growth of tested fungi about 36–56%. Then, F221-B was further evaluated for its ability of controlling lettuce root rot and wilt caused by F442-G in hydroponics. It was revealed that F221-B reduced disease incidence and severity about 60–80% compared to the inoculated control and significantly promoted the growth of 3 lettuce varieties. Interestingly, using only F221-B gave the significantly highest fresh weight (twice over the healthy control). Conclusively, this study provides an important suggestion for further development of F221-B since it showed the ability of biocontrol agent and plant growth promoting fungus.

scholarly journals Regional Evaluation of Fungal Pathogen Incidence in Colombian Cocoa Crops

Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 44
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Osma ◽  
Oscar Ortíz-Rodriguez
Keyword(s):  
Fungal Pathogens ◽  
Morphological Variability ◽  
Phytopathogenic Fungi ◽  
Phytophthora Palmivora ◽  
In Vitro Assays ◽  
Post Conflict ◽  
Solid Media ◽  
Black Pod

The production of cocoa (Theobroma cacao L.) in Colombia has a significant environmental and socioeconomic importance as a promissory crop in the post-conflict process. The department of Norte de Santander has cocoa crops that are dramatically affected by fungal pathogens causing important losses during harvest and post-harvest. Therefore, the current study focused on the determination of the incidence of diseases caused by phytopathogenic fungi in cocoa crops, and the identification of primary phytopathogenic fungi found in biological material from different farms of the region. The study was conducted in four municipalities of the department, by sampling fruits infected with frosty pod rot (FPR) and black pod rot (BPR) that presented in situ incidence ranging from 0.37 to 21.58% and from 1.75 to 35.59%, respectively. The studied hybrid materials, together with clone TSH 65, were found to be the most susceptible, while the remaining clones were more tolerant, especially CCN 51, IMC 67, and ICS95. Fifteen strains were isolated using in vitro assays and then morphologically characterized both in solid media and by microscopy. Nine of them corresponded to the pathogen Moniliophthora roreri, and other six to Phytophthora palmivora. The isolated agents showed in vitro morphological variability, as well as the ability to adapt to different environments when growing in situ.

Potato-associated bacteria and their antagonistic potential towards plant-pathogenic fungi and the plant-parasitic nematodeMeloidogyne incognita(Kofoid & White) Chitwood

2002 ◽  
Vol 48 (9) ◽  
pp. 772-786 ◽  
Author(s):  
Annette Krechel ◽  
Annekathrin Faupel ◽  
Johannes Hallmann ◽  
Andreas Ulrich ◽  
Gabriele Berg
Keyword(s):  
Fungal Pathogens ◽  
Bacterial Species ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Polymorphism Analysis ◽  
Culturable Bacteria ◽  
Streptomyces Species ◽  
Associated Bacteria ◽  
Antagonistic Potential

To study the effect of microenvironments on potato-associated bacteria, the abundance and diversity of bacteria isolated from the rhizosphere, phyllosphere, endorhiza, and endosphere of field grown potato was analyzed. Culturable bacteria were obtained after plating on R2A medium. The endophytic populations averaged 103and 105CFU/g (fresh wt.) for the endosphere and endorhiza, respectively, which were lower than those for the ectophytic microenvironments, with 105and 107CFU/g (fresh wt.) for the phyllosphere and rhizosphere, respectively. The composition and richness of bacterial species was microenvironment-dependent. The occurrence and diversity of potato-associated bacteria was additionally monitored by a cultivation-independent approach using terminal restriction fragment length polymorphism analysis of 16S rDNA. The patterns obtained revealed a high heterogeneity of community composition and suggested the existence of microenvironment-specific communities. In an approach to measure the antagonistic potential of potato-associated bacteria, a total of 440 bacteria was screened by dual testing for in vitro antagonism towards the soilborne pathogens Verticillium dahliae and Rhizoctonia solani. The proportion of isolates with antagonistic activity was highest for the rhizosphere (10%), followed by the endorhiza (9%), phyllosphere (6%), and endosphere (5%). All 33 fungal antagonists were characterized by testing their in vitro antagonistic mechanisms, including their glucanolytic, chitinolytic, pectinolytic, cellulolytic, and proteolytic activity, and by their BOX-PCR fingerprints. In addition, they were screened for their biocontrol activity against Meloidogyne incognita. Overall, nine isolates belonging to Pseudomonas and Streptomyces species were found to control both fungal pathogens and M. incognita and were therefore considered as promising biological control agents. Key words: biocontrol, antagonistic potential, plant-associated bacteria.

scholarly journals Prevalence and Epidemics of Neoscytalidium Stem and Fruit Canker on Pitahaya (Hylocereus spp.) in South Florida

Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1433-1438
Author(s):  
Cheng-Fang Hong ◽  
Romina Gazis ◽  
Jonathan H. Crane ◽  
Shouan Zhang
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Maximum Growth ◽  
Stem Canker ◽  
South Florida ◽  
In Vitro Assays ◽  
Limited Information ◽  
Disease Epidemiology ◽  
The Aesthetic

Since the 2000s, production of pitahaya (Hylocereus spp.) has increased significantly in South Florida. However, very limited information is available on the main diseases affecting this crop, particularly in regard to disease epidemiology and economic impact on the commodity. In this study, we surveyed five local pitahaya orchards and documented the most prevalent diseases and their causal agents. Three genera of fungal pathogens (Neoscytalidium, Alternaria, and Colletotrichum) were the major groups associated with symptoms on pitahaya cladodes (stems) during the early growing season. Among these, N. dimidiatum was identified as the most prevalent pathogen, with an overall isolation frequency of 29.8% (range, 13.9 to 47.2%). Hence, the temporal progress of N. dimidiatum stem canker infection was monitored and the relationship between stem canker intensity (incidence and severity) and fruit canker incidence was investigated. A significant positive correlation was found between fruit canker incidence and the standardized area under the disease incidence or severity curve on cladodes, suggesting that high stem canker intensity in the early season may contribute to high fruit canker incidence and thereby impact the aesthetic and market value of fruits. In vitro assays showed that both conidial germination and mycelial growth of N. dimidiatum are positively correlated with increasing temperature, with a maximum growth area at 32°C. This finding suggests a higher risk of infection, under an environment with high temperatures, which is common in South Florida. Data obtained in this study represent baseline knowledge for the future development of integrative management programs for controlling major diseases of pitahaya in South Florida.

scholarly journals In vitro interactions between Trichoderma harzianum and pathogenic fungi damaging horse-chestnut (Aesculus hippocastanum) leaves and fruits

2019 ◽  
Vol 54 (1) ◽  
pp. 21-35
Author(s):  
Katarína Pastirčáková
Keyword(s):  
Trichoderma Harzianum ◽  
Fungal Pathogens ◽  
Mutual Influence ◽  
Pathogenic Fungi ◽  
Antagonistic Effect ◽  
Aesculus Hippocastanum ◽  
Horse Chestnut ◽  
Mycelium Growth ◽  
Antagonistic Potential

Abstract Interactions between 3 pathogenic fungi damaging horse-chestnut (Aesculus hippocastanum) leaves and fruits – Phyllosticta sphaeropsoidea, Phomopsis carposchiza, and Diaporthe padi – and the antagonistic fungus Trichoderma harzianum were studied to determine their mutual influence in vitro. Antibiosis of colonies developing on 5 nutrient media was tested. The 3 studied T. harzianum isolates differed in their antagonistic potential. although T. harzianum isolates significantly inhibited the growth of Phomopsis carposchiza, the mycelium growth of some of the re-isolates on fresh medium indicates an inadequate antagonistic effect of T. harzianum on this species. The tested Trichoderma isolates showed stronger antagonism towards the other pathogens, reflected in overgrowing of Phyllosticta sphaeropso-idea and Diaporthe padi and reducing their growth. Granulation of the cytoplasm and lysis of hyphae of the fungal pathogens were the most frequently observed effects of the interaction.

scholarly journals Antifungal activity of chitosan against Alternaria alternata and Colletotrichum gloeosporioides

2018 ◽  
Vol 33 (3-4) ◽  
pp. 197-204 ◽  
Author(s):  
Svetlana Zivkovic ◽  
Milos Stevanovic ◽  
Sanja Djurovic ◽  
Danijela Ristic ◽  
Stefan Stosic
Keyword(s):  
Antifungal Activity ◽  
Alternaria Alternata ◽  
Fungal Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Water Solution ◽  
Disease Incidence ◽  
Fungal Growth ◽  
Promising Alternative

Chitosan and its derivatives have been reported as a promising alternative for control of postharvest fungal pathogens. The objective of this study was to evaluate in vitro and in situ antifungal activity of chitosan against Alternaria alternata and Colletotrichum gloeosporioides isolated from decayed apple fruits. The fungi were tested in vitro using PDA medium with three concentrations of chitosan (1, 2 and 3 mg/ml). Fungal growth of the test pathogens was significantly affected by all chitosan doses (P<0.05) after 7 days of incubation at 25?C. Water solution of 3 mg/ml of chitosan inhibited completely the conidial germination of A. alternata and C. gloeosporioides after 18 h incubation at 25?C. The results obtained from biocontrol assay indicate that the inhibition of postharvest decay of A. alternata and C. gloeosporioides was significantly influenced by chitosan concentrations. Disease incidence in chitosan-treated fruit after 7 days incubation at 25?C was significantly lower than in the positive control for both fungi tested (P<0.05). A. alternata and C. gloeosporioides used in this study were progressively inhibited in vitro and in situ with increasing concentrations of chitosan from 1 to 3 mg/ml.

scholarly journals The Use of Essential Oils from Thyme, Sage and Peppermint against Colletotrichum acutatum

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 114
Author(s):  
Armina Morkeliūnė ◽  
Neringa Rasiukevičiūtė ◽  
Lina Šernaitė ◽  
Alma Valiuškaitė
Keyword(s):  
Essential Oils ◽  
Fungal Pathogens ◽  
Control Plant ◽  
Antimicrobial Activities ◽  
Plant Diseases ◽  
Colletotrichum Acutatum ◽  
Low Toxicity ◽  
Colletotrichum Spp ◽  
Biological Protection

The Colletotrichum spp. is a significant strawberry pathogen causing yield losses of up to 50%. The most common method to control plant diseases is through the use of chemical fungicides. The findings of plants antimicrobial activities, low toxicity, and biodegradability of essential oils (EO), make them suitable for biological protection against fungal pathogens. The aim is to evaluate the inhibition of Colletotrichum acutatum by thyme, sage, and peppermint EO in vitro on detached strawberry leaves and determine EO chemical composition. Our results revealed that the dominant compound of thyme was thymol 41.35%, peppermint: menthone 44.56%, sage: α,β-thujone 34.45%, and camphor: 20.46%. Thyme EO inhibited C. acutatum completely above 200 μL L−1 concentration in vitro. Peppermint and sage EO reduced mycelial growth of C. acutatum. In addition, in vitro, results are promising for biological control. The detached strawberry leaves experiments showed that disease reduction 4 days after inoculation was 15.8% at 1000 μL L−1 of peppermint EO and 5.3% at 800 μL L−1 of thyme compared with control. Our findings could potentially help to manage C. acutatum; however, the detached strawberry leaves assay showed that EO efficacy was relatively low on tested concentrations and should be increased.

scholarly journals Using Commercial Compost as Control Measures against Cucumber Root-Rot Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kamel Kamal Sabet ◽  
Magdy Mohamed Saber ◽  
Mohamed Adel-Aziz El-Naggar ◽  
Nehal Samy El-Mougy ◽  
Hatem Mohamed El-Deeb ◽  
...  
Keyword(s):  
Root Rot ◽  
Control Measure ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
Pythium Ultimum ◽  
Control Measures ◽  
Infested Soil ◽  
Fungal Isolates ◽  
Cucumber Root

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.

Transgenic expression of gallerimycin, a novel antifungal insect defensin from the greater wax moth Galleria mellonella, confers resistance to pathogenic fungi in tobacco

2006 ◽  
Vol 387 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Gregor Langen ◽  
Jafargholi Imani ◽  
Boran Altincicek ◽  
Gernot Kieseritzky ◽  
Karl-Heinz Kogel ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Fungal Pathogens ◽  
Galleria Mellonella ◽  
Ectopic Expression ◽  
Pathogenic Fungi ◽  
Transgenic Expression ◽  
Greater Wax Moth ◽  
Insect Defensin ◽  
Wax Moth

Abstract A cDNA encoding gallerimycin, a novel antifungal peptide from the greater wax moth Galleria mellonella, was isolated from a cDNA library of genes expressed during innate immune response in the caterpillars. Upon ectopic expression of gallerimycin in tobacco, using Agrobacterium tumefaciens as a vector, gallerimycin conferred resistance to the fungal pathogens Erysiphe cichoracearum and Sclerotinia minor. Quantification of gallerimycin mRNA in transgenic tobacco by real-time PCR confirmed transgenic expression under control of the inducible mannopine synthase promoter. Leaf sap and intercellular washing fluid from transgenic tobacco inhibited in vitro germination and growth of the fungal pathogens, demonstrating that gallerimycin is secreted into intercellular spaces. The feasibility of the use of gallerimycin to counteract fungal diseases in crop plants is discussed.

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