scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

scholarly journals 2,4-EPIBRASSIONOLIDE ACTIVATES PRIMING RESISTANCE AGAINST RHIZOPUS STOLONIFER INFECTION IN PEACH FRUIT

2020 ◽  
Vol 49 (2) ◽  
pp. 135-143
Author(s):  
C.H. Li ◽  
M.Y. Du ◽  
K.T. Wang
Keyword(s):  
Fungal Infection ◽  
Inhibitory Effect ◽  
The Other ◽  
Antifungal Compounds ◽  
Rhizopus Stolonifer ◽  
Peach Fruit ◽  
Direct Inhibitory Effect ◽  
Potential Alternative ◽  
Direct Toxicity

This study was conducted to assess the effects of 2,4-epibrassionolide (EBR) on mold decay caused by Rhizopus stolonifer and its capability to activate biochemical defense reactions in postharvest peaches. The treatment of EBR at 5 μM possessed the optimum effectiveness on inhibiting the Rhizopus rot in peach fruit among all treatments. The EBR treatment significantly up-regulated the expression levels of a set of defense-related enzymes and PR genes that included PpCHI, PpGns1, PpPAL, PpNPR1, PpPR1 and PpPR4 as well as led to an enhancement for biosynthesis of phenolics and lignins in peaches during the incubation at 20 °C. Interestingly, the EBR-treated peaches exhibited more striking expressions of PR genes and accumulation of antifungal compounds upon inoculation with the pathogen, indicating a priming defense could be activated by EBR. On the other hand, 5 μM EBR exhibited direct toxicity on fungal proliferation of R. stolonifer in vitro. Thus, we concluded that 5 μM EBR inhibited the Rhizopus rot in peach fruit probably by a direct inhibitory effect on pathogen growth and an indirect induction of a priming resistance. These findings provided a potential alternative for control of fungal infection in peaches during the postharvest storage.

scholarly journals In vitro evaluation of fungal antagonists of Phytophthora nicotianae

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 634-637
Author(s):  
R. Nicoletti ◽  
F. Raimo ◽  
E. Cozzolino
Keyword(s):  
Mycelial Growth ◽  
Central Italy ◽  
Phytophthora Nicotianae ◽  
Aspergillus Sydowii ◽  
Black Shank ◽  
Culture Filtrates ◽  
Dual Cultures ◽  
Penicillium Brevicompactum ◽  
Fusarium Chlamydosporum

As tobacco black shank epidemics caused by Phytophthora nicotianae occurred in central Italy in the late 1990s, fungal antagonists of the pathogen were searched in the rhizosphere of tobacco plants. Isolates of Aspergillus sydowii, Fusarium chlamydosporum, Gliocladium roseum, Penicillium brevicompactum, P. chrysogenum, Scopulariopsis candida and Trichoderma harzianum were recovered. Antagonism of these isolates toward P. nicotianae was evaluated in vitro: even if no hyphal interactions were observed in dual cultures, aberration in mycelial growth and morphology of sporangia occurred in most cases. Unlike those of T. harzianum, concentrated culture filtrates of A. sydowii, F. chlamydosporum, G. roseum, P. brevicompactum, P. chrysogenum, inhibited growth of all P. nicotianae isolates tested, while culture filtrates of S. candida caused aberrant mycelial growth.

scholarly journals Inhibitory effect of the glucosinolate–myrosinase system on Phytophthora cinnamomi and Pythium spiculum

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 93-101 ◽  
Author(s):  
Francisco Teodoro Arroyo Cordero ◽  
Rocío Rodríguez-Arcos ◽  
Ana Jiménez-Araujo ◽  
Rafael Guillén-Bejarano ◽  
María José Basallote ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
High Performance ◽  
Phytophthora Cinnamomi ◽  
Inhibitory Effect ◽  
Reversed Phase ◽  
Field Application ◽  
Additional Information ◽  
Array Detection ◽  
Important Additional Information

Glucosinolate extracts from sprouts of common Brassica nigra, B. juncea cv. Scala, B. carinata cv. Eleven, and Sinapis alba cv. Ludique were analysed by reversed phase high-performance liquid chromatography-diode array detection-mass spectrometry. The effect of the glucosinolate–myrosinase system on in vitro mycelial growth of Phytophthora cinnamomi Rands and Pythium spiculum B. Paul was assessed. Likewise, sinigrin and sinalbin monohydrate commercial standards were also tested. The extracts from B. carinata, which contained 159 mmol/g plant DW equivalent (85% sinigrin, 5% gluconapin, and 3% glucotropaeolin), were the most effective against Phytophthora and Pythium isolates used in this study. However, the extract from S. alba, which contained 1 180 mmol/g (100% sinalbin), did not inhibit the mycelial growth of the isolates tested. The use of the glucosinolate-myrosinase system provides important additional information to advance in the implementation of field application of brassicaceous amendments for the control of soil-borne pathogens.

scholarly journals Sensitivity of Colletotrichum gloeosporioides Isolates from Diseased Avocado Fruits to Selected Fungicides in Kenya

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Stanley Kirugo Kimaru ◽  
E. Monda ◽  
R. C. Cheruiyot ◽  
J. Mbaka ◽  
A. Alakonya
Keyword(s):  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Field Tests ◽  
Inhibitory Effect ◽  
Copper Oxychloride ◽  
Randomized Design ◽  
Agroecological Zones ◽  
Completely Randomized Design ◽  
Growing Region

Colletotrichum gloeosporioides is a serious postharvest pathogen of avocado fruits worldwide. Kenya lacks any registered fungicides for the management of the disease. Nevertheless, farmers commonly use commercially available fungicides such as Bayleton 25WP (Triadimefon 250 g/Kg), Milraz 76WP (Propineb 70% and Cymoxanil 6%), and Copper oxychloride 500WP for disease management. The efficacy of these fungicides against C. gloeosporioides is not known. The purpose of this study was therefore to test the inhibitory effect of these fungicides against 46 C. gloeosporioides isolates from avocado fruits collected from varieties grown at different agroecological zones in Murang’a County, a popular avocado-growing region in Kenya. Mycelial growth rate and sporulation for each isolate were measured in vitro on PDA plates amended with different concentrations of the fungicides. Plates were arranged in a completely randomized design with three replications per treatment. All fungicides were effective in vitro but there were significant differences in sensitivity among isolates. Bayleton had the highest mycelial inhibition followed by Milraz, while copper oxychloride had the lowest mycelial inhibition rates, ranging from 81% to 88%. However, copper oxychloride was more effective in inhibiting sporulation. The inhibitory effect of each fungicide was concentration-dependent, where twice the recommended concentration had the highest inhibitory effect, followed by the recommended concentration. Our results show that the fungicides used by farmers against C. gloeosporioides, the causal agent for anthracnose, are effective. We, however, recommend further field tests in different avocado-growing areas so as to validate their efficacy against various isolates and under different environments.

scholarly journals Evaluation of three plant species to control black scurf disease of Irish potato (Solanum tuberosum Linn.)

2020 ◽  
Vol 12 (1) ◽  
pp. 90-99
Author(s):  
Matthew O. ADEBOLA ◽  
Tunde S. BELLO ◽  
Esther A. SERIKI ◽  
Mariam B. AREMU
Keyword(s):  
Solanum Tuberosum ◽  
Mycelial Growth ◽  
Pathogenic Fungus ◽  
Inhibitory Effect ◽  
Black Scurf ◽  
Irish Potato ◽  
Diffusion Method ◽  
Leaf Extracts

Irish potato (Solanum tuberosum) is an important worldwide food crop and one of the most popular in Nigeria. Its abundance and successful yield have been immensely affected by black scurf disease caused by Rhizoctonia solani. Harnessing a cost-effective management of this pathogenic fungus, three botanical species Acalypha wilkesiana, Moringa oleifera and Carica papaya leaves, each at concentrations of 0 mg ml-1 (control), 25 mg ml-1, 50 mg ml-1 and 75 mg ml-1 were evaluated in vitro. The plant leaf extracts were prepared using methanol and were evaluated for their toxicity using agar well diffusion method. The fungus was isolated from spoilt Irish potato with black scurf symptoms. The results showed the presence of some phytochemicals in leaf extract of each of the plants tested. The three leaves extract independently inhibited mycelial growth of R. solani. The potency of all the plant extracts increased with the increase in concentration. The highest concentration (75 mg ml-1) of M. oleifera and C. papaya evaluated, gave the highest inhibitory effect of 0.81 mm and 1.63 mm respectively, which were not significantly different (p> 0.05), but was obviously different from A. wilkesiana (2.81 mm). Furthermore, M. oleifera extract gave the highest percentage of mycelial growth inhibition of the fungus in all grades of the concentrations evaluated, whereas A. wilkesiana showed the least. The leaves of the three species are therefore recommended for in vivo control of this fungus, owing to their proven efficacy and to their cheap availability.

scholarly journals In Vitro Interactions between Eutypella parasitica and Some Frequently Isolated Fungi from the Wood of the Dead Branches of Young Sycamore Maple (Acer pseudoplatanus)

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1072
Author(s):  
Ana Brglez ◽  
Barbara Piškur ◽  
Nikica Ogris
Keyword(s):  
Competitive Ability ◽  
Inhibitory Effect ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Acer Pseudoplatanus ◽  
Dual Cultures ◽  
Weak Competitor ◽  
The Dead ◽  
In Vitro Interactions

The ten most frequently isolated fungi from the wood of the dead branches of Acer pseudoplatanus L. were tested in dual cultures to evaluate their in vitro antagonistic activity against Eutypella parasitica R.W. Davidson and R.C. Lorenz, the causative agent of a destructive disease of maples in Europe and North America. The tested fungi, treated also as challenge isolates, were Diaporthe sp., Eutypa sp., Eu. maura, E. parasitica, Fusarium avenaceum, Neocucurbitaria acerina, Neonectria sp., Peniophora incarnata, Petrakia irregularis, and Phomopsis pustulata. The antagonistic ability of each challenge isolate was evaluated by calculating an index of antagonism (AI) based on the interaction type in the dual cultures. The results of competition between the fungal isolates were quantified after re-isolations from the interaction zone (s). The dual cultures revealed two main types of competitive interactions: Deadlock, consisting of mutual inhibition after mycelial contact or at a distance, and replacement, reflecting in the inhibition of E. parasitica, followed by partial overgrowth by the replacing fungus. Statistical analysis showed significant differences in average AI and s of challenge isolates between different dual culture assays. Based on the results of the antagonism index, Eutypa sp., Eu. maura, Neonectria sp., and P. incarnata had the highest inhibitory effect on E. parasitica growth and were recognized as the most promising candidates for further biocontrol studies of E. parasitica. The mycelium of E. parasitica at the interaction zones remained mostly viable, except in dual cultures with Eutypa sp., F. avenaceum, and Neonectria sp., where re-isolations did not yield any colony of the E. parasitica isolate. Based on the results, we assume that E. parasitica is a weak competitor, which invests less energy in direct mycelial competition. We discuss the potential of the observed antagonists as a possible biocontrol of Eutypella canker of maple. Nevertheless, additional experiments should be performed for a solid conclusion about competitive ability of E. parasitica and usefulness of antagonists as biocontrol.

scholarly journals Effects of biocontrol agents and plant products Macrophomina phaseolina and colchicine content in Gloriosa superba

2012 ◽  
Vol 48 (No. 3) ◽  
pp. 110-115 ◽  
Author(s):  
D. Alice ◽  
S. Sundravadana
Keyword(s):  
Mycelial Growth ◽  
Foliar Application ◽  
Trichoderma Viride ◽  
Macrophomina Phaseolina ◽  
Biocontrol Agents ◽  
Gloriosa Superba ◽  
Healthy Growth ◽  
Rot Disease ◽  
Tuber Rot

Gloriosa superba is a medicinal plant severely infested with soil-borne Macrophomina phaseolina (Tassi) Goid. Under in vitro conditions a commercial formulation of Trichoderma viride and Pseudomonas fluorescens inhibited the mycelial growth of M. phaseolina isolates. Among the oil cake, mahua cake at 10% completely inhibited the mycelial growth of the M. phaseolina isolates. Under field conditions both the soil and foliar application of biocontrol agents is attributed to the healthy growth of G. superba crops by controlling the tuber rot disease and ultimately boosting the colchicine content.

Evaluation of the effect of a heat-killed lactic acid bacterium, Enterococcus faecalis 2001, on oral candidiasis

2019 ◽  
Vol 10 (6) ◽  
pp. 661-669
Author(s):  
T. Yamazaki ◽  
R. Ushikoshi-Nakayama ◽  
K. Shirone ◽  
M. Suzuki ◽  
S. Abe ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Clinical Study ◽  
Enterococcus Faecalis ◽  
Mycelial Growth ◽  
Oral Candidiasis ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Vitro Study ◽  
Oral Candida

The effect of a preparation of heat-killed Gram-positive lactic acid bacteria Enterococcus faecalis 2001 (EF-2001) on oral candidiasis was evaluated by two studies. An in vitro study was performed to assess the inhibitory effect on mycelial growth of Candida strains isolated from a patient with oral candidiasis, and a clinical study was done in patients with oral candidiasis. In the in vitro study, EF-2001 inhibited mycelial growth of IT-1, a Candida strain isolated from a patient with oral candidiasis, at concentrations ≥2.34×109 cells/ml. An open clinical study was performed in 13 patients with oral candidiasis. The subjects took a powder containing 7.5×1011 heat-killed EF-2001 once a day before bedtime for seven consecutive days. In 11 of the 12 patients available for analysis (92%), the oral Candida load (cfu/swab) showed a significant decrease (P=0.01079, d=-0.437). There was a 55% decrease of Candida albicans and a 93.8% decrease of Candida glabrata. The following symptoms showed significant improvement: tinnitus (P=0.048, d=-0.462), cold feeling (P=0.048, d=-0.463), and depression (P=0.019, d=-0.34). In addition, 4 out of 26 oral symptoms tended to improve. These results suggest that EF-2001 significantly decreased the oral Candida load in patients with oral candidiasis by inhibiting mycelial growth and that EF-2001 is an effective treatment for oral candidiasis.

scholarly journals Antifungal Activity of Quinofumelin against Fusarium graminearum and Its Inhibitory Effect on DON Biosynthesis

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 348
Author(s):  
Qian Xiu ◽  
Lianyu Bi ◽  
Haorong Xu ◽  
Tao Li ◽  
Zehua Zhou ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fusarium Graminearum ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Marker Gene ◽  
Economic Loss ◽  
Inhibitory Effect ◽  
Head Blight ◽  
Excellent Control

Fusarium graminearum, causal agent of Fusarium head blight (FHB), causes a huge economic loss. No information is available on the activity of quinofumelin, a novel quinoline fungicide, against F. graminearum or other phytopathogens. In this study, we used mycelial growth and spore germination inhibition methods to determine the inhibitory effect of quinofumelin against F. graminearum in vitro. The results indicated that quinofumelin excellently inhibited mycelial growth and spore germination of F. graminearum, with the average EC50 values of 0.019±0.007 μg/mL and 0.087 ± 0.024 μg/mL, respectively. In addition, we found that quinofumelin could significantly decrease deoxynivalenol (DON) production and inhibit the expression of DON-related gene TRI5 in F. graminearum. Furthermore, we found that quinofumelin could disrupt the formation of Fusarium toxinsome, a structure for producing DON. Western blot analysis demonstrated that the translation level of TRI1, a marker gene for Fusarium toxinsome, was suppressed by quinofumelin. The protective and curative assays indicated that quinofumelin had an excellent control efficiency against F. graminearum on wheat coleoptiles. Taken together, quinofumelin exhibits not only an excellent antifungal activity on mycelial growth and spore germination, but also could inhibit DON biosynthesis in F. graminearum. The findings provide a novel candidate for controlling FHB caused by F. graminearum.

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