Effect of High Temperature Treatments on Growth of Penicillium spp. and their Development on ‘Valencia’ Oranges

2007 ◽  
Vol 13 (1) ◽  
pp. 63-68 ◽  
Author(s):  
C. Nunes ◽  
J. Usall ◽  
T. Manso ◽  
R. Torres ◽  
M. Olmo ◽  
...  
Keyword(s):  
Citrus Sinensis ◽  
Mycelial Growth ◽  
Quality Parameters ◽  
Potato Dextrose Agar ◽  
In Vitro Growth ◽  
Weight Losses ◽  
Effect Of Treatment ◽  
Curing Regime ◽  
Penicillium Spp

The effect of time (up to 24h) and temperature (40 to 55°C) has been evaluated on in vitro growth of Penicillium digitatum and Penicillium italicum on potato dextrose agar plates or on ‘Valencia’ oranges ( Citrus sinensis), previously inoculated with those pathogens. The effect of treatment on the fruit quality parameters has also been evaluated. In vitro, at 40 and 45°C, an exposure of 24h was required to inhibit subsequent mycelial growth of both pathogens during incubation for 1 week at 25°C. However, at 50 and 55°C, only 18 or 9h (6h for P. digitatum), respectively, were needed to achieve the same effect on both pathogens. Inoculated fruit was exposed for 18h at 40°C then stored for 5 days at 5°C plus 7 days at 20°C, and the experiment was repeated at three locations and over two fruit seasons. This curing regime controlled both pathogens effectively. Concerning quality changes, after cold storage (5°C), treated fruits showed a significant reduction in acid content and a slight delay on skin yellowing, on softening, and on weight losses, compared to the control fruits. These results suggest that the curing treatment could be a non-chemical alternative to the postharvest fungicides now used to control citrus green and blue moulds.

In vitro growth of some species of Ascochyta Lib.

2012 ◽  
Vol 7 (6) ◽  
pp. 1076-1083
Author(s):  
Tomasz Kosiada
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
In Vitro Growth ◽  
Light Conditions ◽  
Oatmeal Agar ◽  
The Family ◽  
Effects Of Temperature

AbstractFungi from the genus Ascochyta are generally facultative saprotrophs, which cause diseases in both monocots and dicots. Over 1 000 species belonging to this genus have been identified, 18 of which infect monocot plants from the family Poaceae. This study analyses the effects of temperature and light on the growth of selected fungi which infect monocots (A. agrostidis, A. avenae, A. brachypodii, A. desmazieri, A. digraphidis, A. ducis-aprutii, A. festucae, A. graminea, A. hordei, A. hordei var. americana, A. hordei var. europea, A. hordei var. hordei, A. melicae, A. phleina, A. skagwayensis, A. sorghi, A. stipae, A. zeicola), grown on three types of media; Potato Dextrose Agar (PDA), Coon’s agar (CN) and oatmeal agar (OMA). The fastest growth among the analyzed fungi at low temperatures was found in Ascochyta melicae, while at high temperatures it was A. zeicola. The fastest in vitro growth (average of all fungi) was observed on CN medium at 20°C (3.4 mm/day), while the lowest on OM medium at 5°C (1.0 mm/day). Radial mycelial growth in dark and the light conditions varied. On average, all isolates grew faster in the dark (3.1 mm/day) than in the light (1.9 mm/day). The greatest effect on the production of pycnidia was found for the isolates. Variation in growth and production of pycnidia depended on temperature, medium and lighting for fungi from the genus Ascochyta infecting monocots. Such variation indicates a potential occurrence of these fungi in different environments.

scholarly journals Baseline Sensitivity of Penicillium spp. to Difenoconazole

Plant Disease ◽  
2019 ◽  
Vol 103 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Wayne M. Jurick ◽  
Otilia Macarisin ◽  
Verneta L. Gaskins ◽  
Wojciech J. Janisiewicz ◽  
Kari A. Peter ◽  
...  
Keyword(s):  
United States ◽  
Mycelial Growth ◽  
The United States ◽  
Blue Mold ◽  
Pome Fruit ◽  
Baseline Sensitivity ◽  
Single Spore ◽  
Commercial Use ◽  
Penicillium Spp

Penicillium spp. cause blue mold of stored pome fruit. These fungi reduce fruit quality and produce mycotoxins that are regulated for processed fruit products. Control of blue mold is achieved by fungicide application, and in 2015 Academy (active ingredients fludioxonil and difenoconazole) was released for use on pome fruit to manage postharvest blue mold. Baseline sensitivity for fludioxonil but not difenoconazole has been determined for P. expansum. To establish the distribution of sensitivity to difenoconazole before commercial use of Academy, 97 unexposed single-spore isolates from the United States and abroad were tested in vitro. Baseline EC50 values ranged from 0.038 to 0.827 µg/ml of difenoconazole with an average of 0.16 µg/ml. Complete inhibition of mycelial growth for all but three isolates occurred at 5 µg/ml of difenoconazole, whereas 10 µg/ml did not support growth for any of the isolates examined. Hence, 5 µg/ml of difenoconazole is recommended for phenotyping Penicillium spp. isolates with reduced sensitivity. Isolates with resistance to pyrimethanil and to both thiabendazole and pyrimethanil were observed among the isolates from the baseline collection. Academy applied at the labeled rate had both curative and protectant activities and controlled four representative Penicillium spp. from the baseline population. This information can be used to monitor future shifts in sensitivity to this new postharvest fungicide in Penicillium spp. populations.

scholarly journals Effect of Agrochemicals Used in the Cultivation of Soybean and Irrigated Rice on Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok

2019 ◽  
Vol 11 (17) ◽  
pp. 167
Author(s):  
Vanessa P. Gonçalves ◽  
Cândida R. J. de Farias ◽  
Victoria Moreira-Nunêz ◽  
Renata Moccellin ◽  
Viviana Gaviria-Hernández ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Spore Germination ◽  
Metarhizium Anisopliae ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Irrigated Rice ◽  
Spray Method ◽  
Fungitoxic Effect

The objective of this work was to evaluate the fungitoxic effect of the agrochemicals used in the cultivation of soybean and irrigated rice on entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae by means of the mycelial growth, sporulation and spore germination. The isolates were inoculated in potato-dextrose-agar (PDA) medium containing the pesticides and exposed to spraying with the products. It was observed that chlorantraniliprole produced the best results regarding and was compatible with the two methods of contact of the product with the fungi. Flubendiamide it’s very toxic to fungi, producing 100% inhibition when incorporated into the medium, when by spraying, the fungus M. anisopliae got mycelial growth. Etofenprox and thiamethoxam changed their toxity classification according to the method of contact with product, was moderately compatible to B. bassiana and compatible to M. anisopliae and spinosad showed more compatibility with M. anisopliae than B. bassiana and was classified as compatible. Among fungicides the tricyclazole was the only compatible with the fungus by the spray method. The results showed that in vitro agrochemicals such as tricyclazole, thiamethoxam, flubendiamide and etofenprox are harmful to fungi. It was found that environmental interference could minimize the effects on organisms, especially when the chemicals are applied by spraying.

Effect of calcium on the growth and virulence of Phytophthora clandestina

2000 ◽  
Vol 40 (1) ◽  
pp. 47 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden
Keyword(s):  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
In Vitro Growth ◽  
Seedling Biomass ◽  
Pathogenic Races ◽  
Glasshouse Experiment ◽  
The Individual

Calcium was found to significantly stimulate both the mycelial growth and virulence of Phytophthora clandestina, the major soilborne fungal pathogen of subterranean clover (Trifolium subterraneum L.). On average, the addition of calcium as either CaCO3 or CaCl2 to 3 artificial media increased the in vitro growth of 15 isolates from 20 to 135%. Calcium was also shown to increase the severity of root disease caused by 6 isolates of P. clandestina by up to 100% in a glasshouse experiment. The addition of Ca2+ as CaCl2 had a greater stimulatory effect on the virulence of P. clandestina towards cv. Woogenellup seedlings (up to 57% reduction in seedling biomass) than supplementing with CaCO3 (maximum 36% decrease). The virulence of 6 isolates from 3 different pathogenic races of P. clandestina were examined in the glasshouse experiment. Differences in the virulence of P. clandestina towards cv. Woogenellup seedlings was shown to be dependent on the individual isolate rather than the pathogenic race to which it is assigned.

Alternative and sustainable control of the fungus Sclerotinia sclerotiorum that causes white mold in soybeans

2021 ◽  
Author(s):  
Sergio E. Lemos da Silva ◽  
Kimberlly Soares Brito Bratifich ◽  
eloisa Teresa Corradini Santos
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Agricultural Production ◽  
Mycelial Growth ◽  
Direct Relationship ◽  
White Mold ◽  
Phytopathogenic Fungus ◽  
Environmental Damage ◽  
In Vitro Growth ◽  
Negative Effect

The Sclerotinia sclerotiorum is a phytopathogenic fungus that causes the White Mold of soybean, being responsible for losses of up to 100% in agricultural production. The objective of this work was to verify and analyze the effect of the raw aqueous extract (EBA) of ginger Zingiber officinalis on a strain of Sclerotinia Sclerotiorum isolated from soybean, cultivated and maintained in vitro in laboratory. The methodology consisted of a longitudinal study of the statistical analysis of the mycelial growth velocity index (MICV), after treatment of the mycelia with different concentrations of aqueous crude extract. The results showed a direct relationship between increasing concentration of EBA and a significant negative effect on the growth of scleroderia. It was possible to conclude that the antifungal activity of ginger EBA was able to inhibit the in vitro growth of Sclerotinia sclerotiorum, with potential protection of soybean crops; it can become a sustainable alternative in the control of this fungus, by decreasing the use of agrochemicals that cause damage to public health and environmental damage.

scholarly journals Toxicity and Resistance Potential of Selected Fungicides to Galactomyces and Penicillium spp. Causing Postharvest Fruit Decays of Citrus and Other Crops

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 87-96 ◽  
Author(s):  
A. H. McKay ◽  
H. Förster ◽  
J. E. Adaskaveg
Keyword(s):  
Mycelial Growth ◽  
Single Spore ◽  
Ph Values ◽  
Highly Active ◽  
Green Mold ◽  
Dmi Fungicides ◽  
Ph Range ◽  
Penicillium Spp ◽  
Twofold Decrease

A diverse collection of isolates of Galactomyces citri-aurantii and G. geotrichum, the causal pathogens of sour rots of citrus and other fruit crops, respectively, was evaluated for sensitivity to demethylation-inhibiting (DMI) fungicides of the triazole group. Propiconazole was found to be highly effective in reducing mycelial growth of both species in vitro. For 139 isolates of G. citri-aurantii, a mean effective concentration for 50% reduction of mycelial growth (EC50 value) of 0.34 μg/ml was determined; whereas, for 33 isolates of G. geotrichum, this value was 0.14 μg/ml. In a comparison of additional DMI fungicides, mean EC50 values for 60 isolates of G. citri-aurantii and 20 isolates of G. geotrichum, were 0.27 and 0.17 μg/ml for cyproconazole, 0.25 and 0.14 μg/ml for metconazole, and 1.16 and 0.73 μg/ml for tebuconazole, respectively. Propiconazole was also highly active against mycelial growth of imazalil-sensitive isolates of Penicillium digitatum, the pathogen that causes green mold of citrus, with a mean EC50 value of 0.008 μg/ml for 63 isolates. Imazalil-resistant isolates of this fungus were cross-resistant to propiconazole. When G. citri-aurantii and P. digitatum were grown at selected pH values between 3 and 9, inhibition by propiconazole occurred over the entire pH range. The fungicide was most effective at pH 5 when compared with the non-fungicide-amended control grown at the same pH. In laboratory mass platings of single-spore isolates sensitive to propiconazole onto selective media, isolates with an up to 81.6-fold decrease in sensitivity to the fungicide were recovered for P. digitatum. For G. geotrichum, isolates with an approximately twofold decrease in sensitivity were obtained. No isolates with reduced sensitivity were recovered for G. citri-aurantii. Propiconazole is currently being registered for postharvest use on citrus and other crops, and the information provided will be valuable in monitoring of fungicide resistance and in designing effective fungicide application strategies.

scholarly journals In vitro sensitivity of Fusarium graminearum, F. avenaceum and F. verticillioides to carbendazim, tebuconazole, flutriafol, metconazole and prochloraz

2011 ◽  
Vol 26 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Dario Ivic ◽  
Zdravka Sever ◽  
Biljana Kuzmanovska
Keyword(s):  
Growth Inhibition ◽  
Fusarium Graminearum ◽  
Mycelial Growth ◽  
Fusarium Species ◽  
Average Concentration ◽  
Potato Dextrose Agar ◽  
Average Growth ◽  
In Vitro Sensitivity

Growth of 13 F. graminearum isolates, 6 F. avenaceum isolates and 6 F. verticillioides isolates was analysed on potato-dextrose agar amended with 0.1, 0.33, 1, 3.3 and 10 mg l-1 of carbendazim, tebuconazole, flutriafol, metconazole, and prochloraz. Average concentration which reduced mycelial growth by 50% comparing it to control (EC50) was calculated for each isolate. Among fungicides tested, prochloraz was shown to be the most effective in growth inhibition of all three species, while flutirafol was proven to be the least effective. Metocnazole was more efficient in comparison with carbendazim and tebuconazole. EC50 values of all isolates on prochloraz were lower than 0.1 mg l-1, while on flutirafol they ranged between 1.66 and 8.51 mg l-1 for 18 isolates, or were higher than 10 mg l-1 for 7 isolates. EC50 values on carbendazim were 0.39-1.41 mg l-1 for F. graminearum isolates, 0.91-1.35 mg l-1 for F. avenaceum, and 0.47-0.6 mg l-1 for F. verticillioides. EC50 values on tebuconazole were 0.85- 2.57 mg l-1 for F. graminearum, 0.85-1.58 mg l-1 for F. avenaceum and 0.22-0.85 mg l-1 for F. verticillioides, while on metconazole EC50 values ranged between less than 0.1 mg l-1 to 1.66, 0.56, and 0.17 mg l-1 for F. graminearum, F. avenaceum and F. verticillioides, respectively. Average growth inhibitions of different Fusarium species and all Fusarium isolates together on different concentrations of fungicides tested were significantly different. Significant differences in growth were not determined among isolates of the same species on neither one of fungicides tested, indicating that no decreased sensitivity to the fungicides exists among isolates included in the study.

scholarly journals Screening of Effective Media for the Growth of Pyricularia grisea under In-vitro Condition

2021 ◽  
Vol 9 (3) ◽  
pp. 131-135
Author(s):  
Ajay Singh Kaurav ◽  
Keyword(s):  
Pearl Millet ◽  
Mycelial Growth ◽  
Agar Medium ◽  
Warm Season ◽  
Potato Dextrose Agar ◽  
Annual Rainfall ◽  
Pyricularia Grisea ◽  
Cereal Crop ◽  
Effective Media

Pearl millet [Pennisetum glaucoma (L.) R. Br.], belongs to family Poaceae (section Paniceae), is the world’s hardiest warm-season cereal crop with the annual rainfall of 150 mm to 1000 mm.Maximum mycelial growth was recorded in potato dextrose carrot agar medium (86.33 mm) followed by Pearl millet Potato dextrose agar (83.67 mm), potato dextrose agar (78.33 mm), Pearl millet carrot dextrose agar (71.67 mm), Pearl millet potato agar (68.33 mm), Carrot dextrose agar (60.67 mm), Pearl millet grain potato dextrose agar (58.33 mm), Oat meal agar (51.67 mm), Pearl millet dextrose agar (51.67 mm), Calcium carbonate agar (42.67 mm), Malt agar (41.00 mm), Water agar (37.33 mm), Pearl millet grain dextrose agar (35.33 mm), Pearl millet agar (30.00) and Yeast extract agar (28.33 mm) while minimum growth was recorded in Pearl millet grain agar (27.33 mm).

scholarly journals Rice Blast in Puerto Rico

1969 ◽  
Vol 62 (3) ◽  
pp. 290-300
Author(s):  
Lii-Jang Liu
Keyword(s):  
Puerto Rico ◽  
Rice Straw ◽  
Rice Blast ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Pyricularia Oryzae ◽  
In Vitro Tests ◽  
Optimum Temperature ◽  
Pathogenicity Tests

Rice blast, which had not been observed during the last six decades in Puerto Rico, reappeared recently in Manatí and in the Gurabo Substation, affecting Brazos, a cultivar introduced from Texas. Pathogenicity tests, as well as studies on the conidial morphology, showed that the fungus isolated from typical blast lesions is Pyricularia oryzae Cav. The physiology of the fungus and its sporulation on various media also were studied. The optimum temperature range, both for mycelial growth and for germination of conidia, was found to be between 24 to 28° C. Sporulation occurred satisfactorily on potato-dextrose agar enriched with coconut milk, and on steamed corn and barley, and rice-straw-decoction agars. In vitro tests with fungicides benomyl, pentachloronitrobenzene, mancozeb, chloroneb, and captan indicated that the first two compounds are the most effective in inhibiting mycelial growth of P. oryzae.

scholarly journals Phosphite fertilisers as inhibitors of Hymenoscyphus fraxineus (anamorph Chalara fraxinea) growth in tests in vitro

2017 ◽  
Vol 59 (1) ◽  
pp. 79-81 ◽  
Author(s):  
Miłosz Tkaczyk ◽  
Artur Pacia ◽  
Marta Siebyła ◽  
Tomasz Oszako
Keyword(s):  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Chalara Fraxinea ◽  
Hymenoscyphus Fraxineus ◽  
Agar Media ◽  
Positive Effect ◽  
Potential Use

Abstract This study is designed to test the potential for reducing the growth of the mycelium of the fungus Hymenoscyphus fraxineus (anamorph Chalara fraxinea) by using phosphite preparations at various concentrations in vitro. The study shows that adding pure phosphite to potato dextrose agar media inhibits the development of the fungus, but if the preparation is applied in the form of ammonium phosphite (Actifos), the growth of fungus will be accelerated. Probably the addition of nitrogen contained in the product Actifos has positive effect on the mycelial growth, but pure phosphite restricts its development. These studies are preliminary and only show the potential use of phosphite to reduce the development of H. fraxineus; however, to completely confirm its operation, further research is needed in this area.

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