scholarly journals MOLECULAR IDENTIFICATION OF FUNGI ISOLATED FROM POSTHARVEST MANGO FRUITS AND EVALUATION OF ESSENTIAL OILS ACTIVITY OF GROWTH INHIBITION

2021 ◽  
Vol 9 (3) ◽  
pp. 178-189
Author(s):  
Adilson Ricken Schuelter ◽  
Fernando Otaviano Da Silva ◽  
Rosane Dos Santos Grignet ◽  
Debora Pereira ◽  
Rafael Francisco Da Silva ◽  
...  

This work aimed to perform the molecular identification of fungi mango fruits, in addition to verifying the effect of the essential oils for microbial control. Pericarp segments containing injured and healthy areas of mango fruits were initially disinfested, and then incubated in PDA culture medium at 25 °C. From all isolated material, UDC03, UDC04, UDC09 and UDC12 were preselected, which presented homogeneous cultures. The UDC04 and UDC12 isolates were submitted to the sequencing of the ITS region for presenting mycelial growth both greater and morphologically distinct of fungi from Colletotrichum genus. When BLAST is used in species identification, it was observed that UDC04 and UDC12 belong to Botryosphaeria dothidea and Neofusicoccum parvum, respectively. Regarding the control of UDC04, it was observed that BDA culture medium containing 1.5 to 2% of lemongrass and eucalyptus oils resulted in complete inhibition. For UDC12, mycelial growth inhibition was detected with the use of 1% and 1.5% essential oils of eucalyptus and lemongrass, respectively. The chia essential oil was not effective for the isolates control. Finally, the results reveal the importance of molecular identification of these phytopathogens associated with the establishment of an alternative control of fruits due to problems of contamination with chemical products.

10.5219/1483 ◽  
2021 ◽  
Vol 15 ◽  
pp. 210-217
Author(s):  
Veronika Valková ◽  
Hana Ďúranová ◽  
Lucia Galovičová ◽  
Eva Ivanišová ◽  
Miroslava Kačániová

The current study aimed to investigate antifungal activities of two commercially available essential oils (EOs), specifically Tea tree oil (Melaleuca alternifolia; TTEO) and St. John's wort oil (Hypericum perforatum; HPEO) against three Penicillium (P.) species: P. citrinum, P. expansum, and P. crustosum in in situ conditions. For this purpose, EOs were applied in the vapor phase to determine the growth inhibition of fungi artificially inoculated on sliced bread. Changes in colony growth rate were evaluated as markers for the mycelial growth inhibition (MGI) effect of the EOs. The antioxidant activities of the EOs were evaluated using the DPPH method. The moisture content (MC) and water activity (aw) of bread as a substrate for fungal growth were also measured. From the DPPH assay, we have found that both EOs (TTEO, HPEO) exhibited strong antioxidant activity (64.94 ±7.34%; 70.36 ±1.57%, respectively). The values for bread MC and aw were 43.01 ±0.341% and 0.947 ±0.006, respectively. Our results suggest that HPEO is the only weak inhibitor of P. citrinum and P. crustosum colony growths. Also, the highest concentrations of TTEO display only the weak capability of mycelial growth inhibition of P. citrinum and P. crustosum. By contrast, the colony growth of P. expansum was enhanced by both EOs at all levels used. In conclusion, the application of both EOs in the vapor phase against selected Penicillium species seems not to be a promising alternative to chemical inhibitors used for bread preservation.


2020 ◽  
Vol 7 (03) ◽  
Author(s):  
PREM PANDEY ◽  
G. C. SAGAR ◽  
SUNDARMAN SHRESTHA2 ◽  
HIRAKAJI MANANDHAR ◽  
RITESH K. YADAV ◽  
...  

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).


Author(s):  
Letizia Mondani ◽  
Giorgio Chiusa ◽  
Paola Battilani

AbstractThe aim of the study was to test in vitro and in vivo the efficacy of triazoles and biocontrol agents (BCAs) against Fusarium proliferatum and F. oxysporum, the former signaled as the main causal agent of garlic dry rot and the latter also involved. In vitro trials were organized using potato dextrose agar with added chemicals or BCAs inoculated with selected F. proliferatum and F. oxysporum. Garlic cloves were dipped before sowing in suspensions prepared with the fungicides showing the best performances in vitro; then they were dipped in Fusaria suspension before sowing. In in vitro trials, the maximum Fusaria growth inhibition was performed by Propiconazole + Prochloraz (100%), followed by Tebuconazole (88.9%). BCAs showed great capacity to control Fusaria, with a maximum growth inhibition of 80% (Trichoderma harzianum + T. gamsii). In vivo bacterial BCAs showed a similar capacity to control F. proliferatum and F. oxysporum compared to chemical products (mean of severity index 18.6% and 11.7%, respectively). In vivo results confirmed the in vitro performances, except for Trichoderma, which had the worst performances in vivo. Therefore, the results are preliminary but promising for future field application.


Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Xiao Hong Lu ◽  
R. Michael Davis ◽  
S. Livingston ◽  
J. Nunez ◽  
Jianjun J. Hao

The identity of 172 isolates of Pythium spp. from cavity spot lesions on carrot produced in California and Michigan was determined, and their sensitivity to three fungicides was examined. Pythium violae accounted for 85% of California isolates, with P. irregulare, P. dissotocum (the first report as a carrot pathogen in the United States), P. ultimum, and P. sulcatum making the balance. P. sulcatum, P. sylvaticum, and P. intermedium were the most commonly recovered (85%) species in Michigan; others from Michigan included P. intermedium, P. irregulare, and an unclassified strain, M2-05. On fungicide-amended media, 93% of isolates were sensitive to mefenoxam (inhibition of mycelial growth was >60% at 10 μg active ingredient [a.i.]/ml); however, two of five isolates of P. irregulare from California were highly resistant (≤60% inhibition at 100 μg a.i./ml); about half of the isolates of P. intermedium and P. sylvaticum and a single isolate of P. violae were highly or intermediately resistant to mefenoxam (>60% inhibition at 100 μg a.i./ml, or ≤60% inhibition at 10 μg a.i./ml). P. dissotocum, P. irregulare, P. sulcatum, M2-05, and three of seven isolates of P. intermedium were insensitive to fluopicolide (effective concentrations for 50% growth inhibition [EC50] were >50 μg a.i./ml), while P. sylvaticum, P. ultimum, P. violae, and some isolates in P. intermedium were sensitive (EC50 < 1 μg a.i./ml). All isolates were sensitive to zoxamide (EC50 < 1 μg a.i./ml). Sensitivity baselines of P. violae to zoxamide and fluopicolide were established.


2016 ◽  
Vol 41 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Sittiporn Parnmen ◽  
Sujitra Sikaphan ◽  
Siriwan Leudang ◽  
Thitiya Boonpratuang ◽  
Achariya Rangsiruji ◽  
...  

2014 ◽  
Vol 8 (34) ◽  
pp. 3171-3177
Author(s):  
Kamel Kossonou Yao ◽  
Clementine Kouakou Amenan ◽  
Daniel Kra Kouam ◽  
H. Tra Bi Fezan ◽  
A. Diallo Hortense ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Victor Olusegun Oyetayo

Molecular identification of eighteenTermitomycesspecies collected from two states, Ondo and Ekiti in Nigeria was carried out using the internal transcribed spacer (ITS) region. The amplicons obtained from rDNA ofTermitomycesspecies were compared with existing sequences in the NCBI GenBank. The results of the ITS sequence analysis discriminated between all theTermitomycesspecies (obtained from Ondo and Ekiti States) andTermitomycessp. sequences obtained from NCBI GenBank. The degree of similarity of T1 to T18 to gene ofTermitomycessp. obtained from NCBI ranges between 82 and 99 percent.Termitomycesspecies from Garbon with ascension number AF321374 was the closest relative of T1 to T18 except T12 that has T. eurhizus and T. striatus as the closet relative. Phylogenetic tree generated with ITS sequences obtained from NCBI GenBank data revealed that T1 to T18 are more related toTermitomycesspecies indigenous to African countries such as Senegal, Congo, and Gabon.


2016 ◽  
Vol 83 (0) ◽  
Author(s):  
Elisabeth Wisbeck ◽  
Endi Pricila Alves ◽  
Styfanie Gonçalves de Lima ◽  
Regina Maria Miranda Gern ◽  
Marcia Luciane Lange Silveira ◽  
...  

ABSTRACT: This study evaluated the use of immersion water from peach palm leaves (PPLDA) as a component of the culture medium for the maintenance of Pleurotus spp. and the use of agricultural waste, peach palm leaves, as inoculum support for the fungi. The performance of the inoculum based on peach palm leaves (PPL) for the production of Pleurotus spp. fruiting bodies was compared with that using wheat grains (WG) as inoculum support. PPLDA culture medium (immersion water of peach palm leaves, dextrose, and agar) showed a lower radial velocity of mycelial growth for both fungi than that obtained with the culture medium WDA (wheat extract, dextrose and agar), commonly used as maintenance medium for Pleurotus spp. However, the type of inoculum support does not significantly influence the linear velocity of P. ostreatus mycelial growth, reaching 6.71 mm/day on wheat grains and 6.18 mm/day on peach palm leaves. Thus, when the inoculum based on peach palm leaves is utilized, the immersion water used for preparing this support can be used for preparing the PPLDA maintenance culture medium, diminishing the production costs of Pleurotus mushrooms. Data also showed that when Pleurotus sajor-caju was cultivated on peach palm leaves, using PPL as inoculum support, the fruiting bodies production parameters (Y = 47%, BE = 3% and Pr = 0.2 g/day) did not differ from that obtained using WG.


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