scholarly journals Effect of the mycoflora of ergot (Claviceps purpurea)sclerotia on their viability

2010 ◽  
Vol 46 (No. 2) ◽  
pp. 66-71 ◽  
Author(s):  
M. Ondřej ◽  
B. Cagaš ◽  
E. Ondráčková
Keyword(s):  
Trichoderma Harzianum ◽  
Fungal Species ◽  
In Vitro Tests ◽  
Conidial Suspension ◽  
Claviceps Purpurea ◽  
Clonostachys Rosea ◽  
Trichoderma Hamatum ◽  
Total Destruction ◽  
One Year

Twenty fungal species were isolated from sclerotia of ergot (Claviceps purpurea) originating from rye. In in vitro tests with the anamorphic stage of ergot (known as Sphacelia segetum) high mycoparasitic activity was exhibited only by two of them – Clonostachys rosea and Trichoderma harzianum, moderate mycoparasitic activity was detected in Ulocladium sp., Clonostachys catenulata, Trichoderma hamatum, and Trichothecium roseum. In in vitro tests of mycoparasitic activity with sclerotia of the fungus Sclerotinia sclerotiorum their rapid and total destruction was brought about only by the fungi Clonostachys rosea and Trichoderma harzianum. The viability of overwintering ergot sclerotia in the soil was influenced by their placement, age, depth of placement and treatment with a conidial suspension of the fungus Clonostachys rosea. The highest viability values were reported in fresh one-year-old sclerotia. In two-year-old sclerotia their viability was reduced and their sensitivity to microbial activity was higher. The sclerotia aged 3 years or more did not germinate and were all microbiologically degraded in the soil. More than 80% of degradation of sclerotia which were 1 to 2 years old was caused by the fungus Clonostachys rosea. The degradation of sclerotia aged 3 to 4 years was brought about by bacteria, soil edafauna (mites, nematodes) and fungi of the genera Trichoderma, Fusarium, Clonostachys, etc.

scholarly journals Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)

Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Angela Brunetti ◽  
Antonio Matere ◽  
Valentina Lumia ◽  
Vittorio Pasciuta ◽  
Valeria Fusco ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Fungal Species ◽  
In Vitro Tests ◽  
Wood Discoloration ◽  
Olive Groves ◽  
Pathogenicity Tests ◽  
Olive Quick Decline Syndrome ◽  
Olive Trees ◽  
Branch Dieback

Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by wood discoloration, bark canker, and canopy blight. During surveys of olive groves in Apulia (southern Italy), we noticed that—in some areas—trees were heavily affected by severe branch and twig dieback. In addition, chlorosis and the appearance of red-bronze patches on the leaf preceded the wilting of the foliage, with necrotic leaves persisting on the twigs. Given the severity of the manifestation in zones also subject to olive quick decline syndrome (OQDS) caused by Xylella fastidiosa subsp. pauca, we investigated the etiology and provide indications for differentiating the symptoms from OQDS. Isolation from diseased wood samples revealed a mycete, which was morphologically and molecularly identified as N. mediterraneum. The pathogenicity tests clearly showed that this fungus is able to cause the natural symptoms. Therefore, also considering the low number of tested samples, N. mediterraneum is a potential causal agent of the observed disease. Specifically, inoculation of the twigs caused complete wilting in two to three weeks, while inoculation at the base of the stem caused severe girdling wedge-shaped cankers. The growth rate of the fungus in in vitro tests was progressively higher from 10 to 30 °C, failing to grow at higher temperatures, but keeping its viability even after prolonged exposure at 50 °C. The capacity of the isolate to produce catenulate chlamydospores, which is novel for the species, highlights the possibility of a new morphological strain within N. mediterraneum. Further investigations are ongoing to verify whether additional fungal species are involved in this symptomatology.

scholarly journals Biological Control of the Root-Knot Nematode Meloidogyne javanica by Trichoderma harzianum

2001 ◽  
Vol 91 (7) ◽  
pp. 687-693 ◽  
Author(s):  
E. Sharon ◽  
M. Bar-Eyal ◽  
I. Chet ◽  
A. Herrera-Estrella ◽  
O. Kleifeld ◽  
...  
Keyword(s):  
Biological Control ◽  
Proteolytic Activity ◽  
Trichoderma Harzianum ◽  
Meloidogyne Javanica ◽  
In Vitro Assays ◽  
In Vitro Tests ◽  
Root Knot Nematode ◽  
Soil Extracts ◽  
Greenhouse Experiments

The fungal biocontrol agent, Trichoderma harzianum, was evaluated for its potential to control the root-knot nematode Meloidogyne javanica. In greenhouse experiments, root galling was reduced and top fresh weight increased in nematode-infected tomatoes following soil pretreatment with Trichoderma peat-bran preparations. The use of a proteinase Prb1-transformed line (P-2) that contains multiple copies of this gene improved biocontrol activity in the greenhouse experiments compared with the nontransformed wild-type strain (WT). All the Trichoderma strains showed the ability to colonize M. javanica-separated eggs and second-stage juveniles (J2) in sterile in vitro assays, whereas P-2 also penetrated the egg masses. This protease-transformed line presented the same nematicidal and overall proteolytic activity as the WT in in vitro tests in which concentrated soil extracts from Trichoderma-treated soils immobilized the infective J2. However, the J2 immobilization and proteolytic activities of both P-2 and the WT were higher than those obtained with strain T-203. Characterization of the activity of all Trichoderma strains soil extracts on J2 showed that it was heat resistant and restricted to the low-molecular-weight fraction (less than 3 kDa). It is suggested that improved proteolytic activity of the antagonist may be important for the biological control of the nematodes.

scholarly journals Native Trichoderma grown on oat grains controls damping-off and enhances height in soybean

2017 ◽  
Vol 47 (1) ◽  
pp. 102-109
Author(s):  
Alexandre Dinnys Roese ◽  
Gloria Soriano Vidal ◽  
Erica Camila Zielinski ◽  
Louise Larissa May De Mio
Keyword(s):  
Higher Plants ◽  
Biological Control Agent ◽  
In Vitro Tests ◽  
Dual Culture ◽  
Conidial Suspension ◽  
Damping Off ◽  
Trichoderma Spp ◽  
Agrosilvopastoral Systems

ABSTRACT Trichoderma is a biological control agent used to improve the resistance to diseases, which may also estimulate plant growth. Commercial products with Trichoderma are available in different countries, but most of them are based on conidial suspension. This study aimed at evaluating the efficiency of native Trichoderma populations collected from different production systems and applied to the soil by using two methods: conidial suspension and inoculated oat grains. The efficiency of native Trichoderma populations collected from conventional crop and agropastoral and agrosilvopastoral systems in a long-term field experiment was evaluated. The populations efficiencies were evaluated by in vivo tests that assessed the control of soybean damping-off caused by Rhizoctonia solani, plant height and soil colonization with the antagonist. In vitro tests, such as dual culture and assessment of volatile and non-volatile compounds, were conducted to study the mode of action of the populations. Some native Trichoderma populations were as efficient as those from a commercial product in all tests. Compared to conidial suspension, Trichoderma spp. inoculated through oat grains promoted a greater damping-off control, higher plants and more colony-forming units per gram of soil after 3 months of application. Native populations performed equally well or even better than the commercial strain, and the use of a substrate that supports the Trichoderma growth was more efficient than the conidial suspension method.

scholarly journals Chemical Composition and Antifungal Activity of Essential Oils from Flowers, Leaves, Rhizomes, and Bulbs of the Wild Iraqi Kurdish Plant Iris Persica

2017 ◽  
Vol 12 (3) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Hawraz Ibrahim M. Amin ◽  
Ahmed Anwar Amin ◽  
Solveig Tosi ◽  
Giorgio Giacomo Mellerio ◽  
Faiq H. S. Hussain ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Essential Oils ◽  
Antimicrobial Agents ◽  
Trichophyton Mentagrophytes ◽  
Fungal Species ◽  
Volatile Fraction ◽  
In Vitro Tests ◽  
Microsporum Canis ◽  
Main Component

Essential oils obtained by hydrodistillation of different parts of Iris persica L. were investigated for the first time by GC-FID and GC-MS; moreover, their antifungal activities were determined. 34, 32, 27, and 17 compounds were identified in the oils from air-dried flowers, leaves, rhizomes and fresh bulbs, respectively, representing ≥ 98% each oil. The major constituents of the flower essential oil were phenylethanol (24.8%) and furfural (13.8%), which, as the main component, constituted also 39.0% and 22.2% of the leaf and rhizome volatile fractions, respectively. Phenylacetaldehyde (37.1%) was the main constituent of the bulb volatile fraction. In in vitro tests, moderate antifungal activity was detected for the oils against strains of the human pathogenic fungal species Candida albicans, Microsporum canis, and Trichophyton mentagrophytes, the plant-fungal pathogen Pyricularia oryzae, and the fungal food contaminant Aspergillus carbonarius,. The highest activity was exhibited by the essential oils from leaves and flowers, suggesting that they could be considered natural antimicrobial agents.

scholarly journals On the Applicability of Chitosan Oligomers-Amino Acid Conjugate Complexes as Eco-Friendly Fungicides against Grapevine Trunk Pathogens

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 324
Author(s):  
Laura Buzón-Durán ◽  
Natalia Langa-Lomba ◽  
Vicente González-García ◽  
José Casanova-Gascón ◽  
Jesús Martín-Gil ◽  
...  
Keyword(s):  
Amino Acid ◽  
Wood Decay ◽  
Field Trials ◽  
Fungal Species ◽  
In Vitro Tests ◽  
In Planta ◽  
Management Culture ◽  
Amino Acid Conjugate ◽  
Acid Conjugate

In a context in which the incidence and severity of grapevine fungal diseases is increasing as a result of both climate change and modern management culture practices, reducing the excessive use of phytosanitary products in viticulture represents a major challenge. Specifically, grapevine trunk diseases (GTDs), caused by several complexes of wood decay or xylem-inhabiting fungi, pose a major challenge to vineyard sustainability. In this study, the efficacy of chitosan oligomers (COS)–amino acid conjugate complexes against three fungal species belonging to the Botryosphaeriaceae family (Neofusicoccum parvum, Diplodia seriata, and Botryosphaeria dothidea) was investigated both in vitro and in planta. In vitro tests led to EC50 and EC90 effective concentrations in the 254.6−448.5 and 672.1−1498.5 µg·mL−1 range, respectively, depending on the amino acid involved in the conjugate complex (viz. cysteine, glycine, proline or tyrosine) and on the pathogen assayed. A synergistic effect between COS and the amino acids was observed against D. seriata and B. dothidea (synergy factors of up to 2.5 and 2.8, respectively, according to Wadley’s method). The formulations based on COS and on the conjugate complex that showed the best inhibition rates, COS−tyrosine, were further investigated in a greenhouse trial on grafted vines of two varieties (”Tempranillo” on 775P and “Garnacha” on 110R rootstock), artificially inoculated with the mentioned three Botryosphaeriaceae species. The in planta bioassay revealed that the chosen formulations induced a significant decrease in disease severity against N. parvum and B. dothidea. In summary, the reported conjugate complexes may be promising enough to be worthy of additional examination in larger field trials.

Control of white rot of garlic by antagonistic fungi under controlled environmental conditions

1984 ◽  
Vol 30 (7) ◽  
pp. 884-889 ◽  
Author(s):  
Vetúria L. de Oliveira ◽  
Margarida de M. Bellei ◽  
Arnaldo Chaer Borges
Keyword(s):  
Cell Wall ◽  
Trichoderma Harzianum ◽  
Environmental Conditions ◽  
Paecilomyces Lilacinus ◽  
White Rot ◽  
Infested Soil ◽  
Conidial Suspension ◽  
Sclerotium Cepivorum ◽  
Penicillium Sp

Several fungi were isolated from soil samples collected in areas with a high incidence of white rot disease of garlic at Amarantina county, Minas Gerais, Brazil. After the screening in vitro for antagonists to Sclerotium cepivorum, three fungi were found to be highly inhibitory to the pathogen. These fungi were identified as Trichoderma harzianum Rifai, Paecilomyces lilacinus (Thom.) Samson, and a Penicillium sp. The three antagonists produced in vitro nonvolatile antibiotics towards Sc. cepivorum. These substances were thermolabile (120 °C, 15 min) and significantly inhibited the growth of Sc. cepivorum. Interactions between the pathogen and each antagonist, studied by a dual slide-mount technique, showed that Pa. lilacinus and Penicillium sp. caused an inhibition halo to Sc. cepivorum although hyphal contact never occurred. Trichoderma harzianum showed inhibitory activity at a distance, and after contact with Sc. cepivorum, caused hyphal cytoplasm disintegration and cell wall collapse. This detrimental effect occurred either after direct penetration of the cell wall or after the formation of "coilings." The efficacy of the three antagonists in the biocontrol of white rot was tested under controlled environmental conditions in a nonsterilized, artificially infested soil (1 sclerotia per gram of soil). Trichoderma harzianum VL1 applied as a conidial suspension (106 conidia/mL) during the transplanting period significantly reduced the severity of white rot and increased the number of healthy plants when compared with the untreated control. Trichoderma harzianum gave significantly better protection to the plants than Coniothyrium minitans, a known biocontrol agent of sclerotia-forming fungi. Paecilomyces lilacinus, Penicillium sp., and the mixture of the three antagonists gave no protection against the disease.

scholarly journals Induced Systemic Resistance (ISR) in Arabidopsis thaliana by Bacillus amyloliquefaciens and Trichoderma harzianum Used as Seed Treatments

Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 166
Author(s):  
Barakat Ilham ◽  
Chtaina Noureddine ◽  
Grappin Philippe ◽  
El Guilli Mohammed ◽  
Ezzahiri Brahim ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Trichoderma Harzianum ◽  
Bacillus Amyloliquefaciens ◽  
Defense Mechanism ◽  
Fungal Species ◽  
Antagonistic Activity ◽  
Systemic Resistance ◽  
Bacillus Species

The Trichoderma fungal species and the bacteria Bacillus species were described as inducers of plant systemic resistance in relation to their antagonistic activity. The objective of this study was to evaluate the effect of selected strains of Bacillus amyloliquefaciens (I3) and Trichoderma harzianum (A) on inducing systemic resistance in Arabidopsis thaliana as a model for plant molecular genetics. The microorganisms were identified and were confirmed for their antagonistic potential in vitro and in vivo in previous studies. In order to explore this mechanism, two mutants of A. thaliana carrying a PR1 promoter (a conventional marker of salicylic acid (SA) pathway) and LOX2 promoter (a marker triggering jasmonic acid (JA) pathway activation) were analyzed after inoculating antagonists. Transgenic reporter line analysis demonstrated that B. amyloliquefaciens I3 and T. harzianum A induce A. thaliana defense pathways by activating SA and JA at a high level compared to lines treated with chemical elicitors of references (acibenzolar-S-methyl (Bion 50 WG (water-dispersible granule)), SA, and methyl jasmonate). The efficacy of B. amyloliquefaciens I3 and T. harzianum A in inducing the defense mechanism in A. thaliana was demonstrated in this study.

Preharvest Applications of Fungicides for Control of Sphaeropsis Rot in Stored Apples

2013 ◽  
Vol 14 (1) ◽  
pp. 9
Author(s):  
Y. K. Kim ◽  
C. L. Xiao
Keyword(s):  
Mycelial Growth ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Economic Losses ◽  
In Vitro Tests ◽  
Conidial Suspension ◽  
Growth Assay ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple in Washington State and causes significant economic losses. Infection of apple fruit by the fungus occurs in the orchard, but decay symptoms develop during storage or in the market. The objective of this study was to evaluate preharvest fungicide applications to control Sphaeropsis rot. Thirty isolates of the fungus collected from various sources were tested for sensitivity to the registered fungicides Pristine, Topsin M, and Ziram using an in vitro mycelial growth assay. In the orchard, ‘Golden Delicious' apple fruit were inoculated with the conidial suspension of the fungus at 2 or 5 weeks before harvest, sprayed with fungicides within 2 weeks before harvest, and harvested and stored at 0°C for disease evaluation. All three fungicides effectively inhibited mycelial growth of the fungus in the in vitro tests. On apple fruit in four seasons, Pristine applied 1 week and Ziram applied 2 weeks before harvest significantly reduced incidence of Sphaeropsis rot compared to the nontreated control by 43 to 80% and 42 to 83%, respectively. In 4 years of testing, the performance of Topsin M was less consistent than that of Pristine and Ziram. Accepted for publication 18 July 2013. Published 19 September 2013.

scholarly journals Efecto in vitro de controladores biológicos sobre Colletotrichum spp. y Botrytis spp.

2017 ◽  
Vol 1 (2) ◽  
pp. 25
Author(s):  
Malluri Goñas Goñas ◽  
Leidy Gheraldinne Bobadilla Rivera ◽  
Jesús Rascón ◽  
Nora Y. Vera Obando
Keyword(s):  
Trichoderma Harzianum ◽  
Clonostachys Rosea ◽  
Trichoderma Spp ◽  
Colletotrichum Spp

<p>La presente investigación, realizada en el Laboratorio de Investigación de Entomología y Fitopatología de la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, tuvo el objetivo de evaluar el efecto in vitro de cuatro controladores biológicos (Trichoderma harzianum, T. viride, T. asperellum y Clonostachys rosea) frente a los hongos patógenos Colletotrichum spp. y Botrytis spp. Se utilizó la metodología de cultivos duales, que consiste en enfrentar el enemigo biológico en un extremo de una placa Petri y el hongo patógeno en el otro. Se establecieron seis tratamientos que incluyeron un testigo absoluto y un testigo químico (propineb 1000 ppm) por patógeno, con cinco repeticiones por tratamiento. Se logró el aislamiento de los fitopatógenos Colletotrichum spp., agente causal de la antracnosis del mango, y Botrytis spp., agente causal de la rancha en azucenas. Al comparar el crecimiento radial cada 24 horas, se encontró que 96 horas después del enfrentamiento, las cepas de Trichoderma inhibieron el crecimiento radial de los patógenos, diferenciándose significativamente del testigo absoluto. Al evaluar el porcentaje de inhibición del crecimiento radial (PICR) en Botrytis spp., las cepas de Trichoderma spp. presentaron mayor PICR, sin embargo, no presentaron diferencias significativas con el testigo químico. En Colletotricum spp., las cepas de Trichoderma spp. presentaron mayor PICR, y además diferencias significativas estadísticas con el testigo químico. Finalmente, cabe destacar que la cepa de C. rosea no inhibió el crecimiento radial de los patógenos, mostrando los PICR más bajos.</p>

Anti-Diabetic Activity of a Mineraloid Isolate, in vitro and in Genetically Diabetic Mice

2011 ◽  
Vol 81 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Joel Deneau ◽  
Taufeeq Ahmed ◽  
Roger Blotsky ◽  
Krzysztof Bojanowski
Keyword(s):  
Dna Microarrays ◽  
Human Fibroblasts ◽  
Diabetic Animal ◽  
In Vitro Tests ◽  
Diabetic Mice ◽  
Fossil Material ◽  
Expression Of Genes ◽  
Enhanced Expression ◽  
Genetically Diabetic Mice

Type II diabetes is a metabolic disease mediated through multiple molecular pathways. Here, we report anti-diabetic effect of a standardized isolate from a fossil material - a mineraloid leonardite - in in vitro tests and in genetically diabetic mice. The mineraloid isolate stimulated mitochondrial metabolism in human fibroblasts and this stimulation correlated with enhanced expression of genes coding for mitochondrial proteins such as ATP synthases and ribosomal protein precursors, as measured by DNA microarrays. In the diabetic animal model, consumption of the Totala isolate resulted in decreased weight gain, blood glucose, and glycated hemoglobin. To our best knowledge, this is the first description ever of a fossil material having anti-diabetic activity in pre-clinical models.

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