scholarly journals Evaluation of Onion Cultivars for Resistance to Aspergillus niger, the Causal Agent of Black Mold

2002 ◽  
Vol 127 (4) ◽  
pp. 697-702 ◽  
Author(s):  
Swee-Suak Ko ◽  
Jenn-Wen Huang ◽  
Jaw-Fen Wang ◽  
Subramanyam Shanmugasundaram ◽  
Woo-Nang Chang
Keyword(s):  
Aspergillus Niger ◽  
Incubation Temperature ◽  
Storage Conditions ◽  
Lesion Size ◽  
Soluble Solids ◽  
Postharvest Disease ◽  
Lesion Diameter ◽  
Screening Protocol ◽  
Black Mold ◽  
Incubation Temperatures

Black mold (BM), caused by Aspergillus niger Tiegh., is a common onion (Allium cepa L.) postharvest disease under hot and humid storage conditions. This study aimed to develop a BM screening protocol, to evaluate onion cultivars for resistance. The effects of pathogen isolate, inoculum density, incubation temperature, and inoculation method on severity of BM were investigated in designing the screening protocol. Variation in virulence was observed and two highly virulent subcultures, An4-2 and An39-3, were selected for study. Disease severity, both in lesion size and sporulation degree, increased with higher inoculum densities and incubation temperatures. In contrast, small lesions and no sporulation were observed when onion scales were inoculated with 1 × 104 spores/mL or incubated at temperatures lower than 20 °C. Inoculation of onion scales or entire bulbs were compared and scale inoculation correlated better with BM incidence in storage. The procedure for BM screening protocol included: wound inoculation of onion slices with 40 μL inoculum suspension of 1 × 105 spores/mL, incubation at 25 °C with 12 hour photoperiod, and rating lesion diameter and sporulation 4 days after inoculation. Using this screening protocol, 42 onion cultivars were evaluated and cultivars with better storability such as `Red Pinoy', `Serrana', `Dehydrator No.3', and `Moonlight' were tolerant to A. niger. These cultivars showed small lesions and no sporulation during screening. On the other hand, cultivars with poor storability like `Texas Early Grano 502', `Granex 429', and `Explorer' exhibited larger lesions with profuse sporulation. Lesion diameter caused by the scale inoculation correlated significantly with bulb storage loss (r = 0.51, P < 0.01) as well as with bulb dry matter (r = -0.48, P < 0.01) and total soluble solids (r = - 0.51, P < 0.01). The screening protocol and tolerant materials are now successfully used in the Asian Vegetable Research and Development Center onion breeding program for resistance to black mold.

scholarly journals Severe Outbreaks of Bunch Rots Caused by Rhizopus stolonifer and Aspergillus niger on Table Grapes in Chile

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 815-815 ◽  
Author(s):  
B. A. Latorre ◽  
S. C. Viertel ◽  
I. Spadaro
Keyword(s):  
Aspergillus Niger ◽  
Cultural Practices ◽  
Weather Conditions ◽  
Soluble Solids ◽  
Vitis Vinifera L ◽  
Rhizopus Stolonifer ◽  
Thompson Seedless ◽  
Table Grapes ◽  
Hypodermic Syringe ◽  
Black Mold

Severe outbreaks of bunch rots (BR) have occurred recently during harvest of table grapes (Vitis vinifera L.) in Chile. Previously, BR was almost exclusively associated with Botrytis cinerea Pers.:Fr. (2,3); however, in 2000 to 2002, BR symptoms were associated with black molds and possibly nonfilamentous yeasts and bacteria. Cvs. Thompson Seedless, Flame Seedless, Ruby Seedless, and Red Globe were severely affected. Symptoms start at the pedicels as soft, watery rots that partially or completely decay infected berries. Longitudinal cracks are produced, a black mold usually develops along the crack fissures, and the skin of the berry turns light gray. Isolations on potato dextrose agar acidified with 1 N lactic acid (APDA) at 0.5 ml/liter, consistently yielded Rhizopus stolonifer (Ehrenb. ex Fr.) Vuillemin and Aspergillus niger Tiegh. R. stolonifer on APDA produced a white-to-gray aerial and nonseptate mycelium, black and globose sporangia with an elliptical collumela, one-celled, globose to oval, striated, almost hyaline sporangiospores, rhizoids, and stolons. A. niger produced septate mycelium. Single-celled, black, rough walled, globose conidia developed on short chains on the second phialides at the tip of globose, upright conidiophores. Mature (soluble solids >16%) detached berries of cv. Thompson Seedless were inoculated with sporangiospores (≈107 spores per ml) of R. stolonifer isolates RS6, RS52, RS73, and RS79 and conidia (≈108 conidia per ml) of A. niger isolates AN12, AN69, and AN75. When berries were aseptically punctured with a sterile hypodermic syringe prior to inoculation, 60 to 86.7% and 42.5 to 100% of berries were infected with R. stolonifer and A. niger, respectively, and both developed BR symptoms (significantly different from control berries) after 48 h in humid chambers at 23°C. Injuries were needed for infection since no infection or only 23.3% of noninjured berries were infected with R. stolonifer and A. niger, respectively. For both pathogens, there was a significant (P < 0.043) interaction between isolates and the presence or absence of injuries. Both pathogens were successfully reisolated on APDA. Fungicide sensitivity tests were performed on detached cv. Thompson Seedless berries challenged by placing an ≈6 μl-drop of inoculum suspension (106 or 107 spores per ml of R. stolonifer isolate RS52 and A. niger isolate AN12, respectively) on injured berries. Pyraclostrobin (0.067 mg/ml) mixed with nicobifen at 0.134 mg/ml (BAS 516 01 F at 0.201 mg a.i./ml, BASF) and copper oxide at 1.2 mg/ml (Cuprodul 60 WP, Quimetal Chile) significantly (P < 0.01) inhibited infection (100% control) by R. stolonifer and A. niger. R. stolonifer was completely controlled by dicloran at 1.88 mg/ml (Botran 75 WP) and partially controlled by captan at 1.6 mg/ml (Captan 80 WP), but A. niger was not controlled by either fungicide. To our knowledge this is the first report of R. stolonifer causing BR of table grape in Chile (4). The severe outbreaks may be associated with warm weather conditions during harvest and injuries caused by birds, insects, or cultural practices. Infection caused by R. stolonifer or A. niger may be followed by sour rot organisms (yeasts or bacteria), as has been suggested elsewhere (1,2). References: (1) E. Gravot et al. Phytoma 543:36, 2001. (2) W. B. Hewitt Page 26 in: Compendium of Grape Diseases, American Phytopathological Society, St. Paul, MN, 1994. (3) B. A. Latorre and G. Vásquez. Aconex (Chile) 52:16, 1996. (4) F. Mujica and C. Vergara. Flora Fungosa Chilena. Universidad de Chile, Facultad de Agronomiacute;a, Santiago, Chile, 1980.

scholarly journals Characterization and optimization of extracellular enzymes production by Aspergillus niger strains isolated from date by-products

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Reda Bellaouchi ◽  
Houssam Abouloifa ◽  
Yahya Rokni ◽  
Amina Hasnaoui ◽  
Nabil Ghabbour ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Enzyme Expression ◽  
Specific Enzyme ◽  
Enzymatic Production ◽  
High Production Rate ◽  
High Production ◽  
Incubation Temperatures ◽  
By Products

Abstract Background This work aims to study the optimal conditions of the fermentation culture medium used for the production of extracellular enzymes (amylase, cellulase, lipase, and protease) from previously isolated Aspergillus niger strains in date by-products. Results The five most powerful isolates selected based on the zone of degradation formed on Petri plates by the substrate were subjected to the quantitative evaluation of their enzymatic production. All five strains showed almost similar API-ZYM profiles, with minor variations observed at the level of some specific enzyme expression. The production of cellulase and amylase was depending on pH and incubation temperatures. ASP2 strain demonstrated the high production rate of amylase (at pH 5 and 30 °C) and cellulase (at pH 6 and 30 °C) for 96 h of incubation. Conclusion The A. niger showed the ability to produce several extracellular enzymes and can be used in the valorization of different agroindustrial residues.

scholarly journals Effect of Storage Conditions on Storability and Antioxidant Potential of Pears cv. ‘Conference’

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 545
Author(s):  
Grzegorz P. Łysiak ◽  
Krzysztof Rutkowski ◽  
Dorota Walkowiak-Tomczak
Keyword(s):  
Mass Loss ◽  
Strong Influence ◽  
Storage Conditions ◽  
Quality Parameters ◽  
Soluble Solids ◽  
Controlled Atmosphere ◽  
Postharvest Diseases ◽  
Market Prices ◽  
Long Period ◽  
The Impact

Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere + 1-MCP—on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and were found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment; at the same time, it is profitable to store ‘Conference’ pears in controlled atmosphere for the same period, no matter whether 1-MCP was applied or not.

Phytotoxic Effect of Decaying Quackgrass (Agropyron repens) Residues

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 595-598 ◽  
Author(s):  
T. V. Toai ◽  
D. L. Linscott
Keyword(s):  
Incubation Temperature ◽  
Soil Surface ◽  
Water Soluble ◽  
Water Extracts ◽  
Phytotoxic Activity ◽  
Phytotoxic Effect ◽  
Effects Of Temperature ◽  
Incubation Temperatures ◽  
Toxin Formation ◽  
Agropyron Repens

We studied the effects of temperature (5, 10, 20, and 30 C) on the phytotoxic activity of decaying quackgrass [Agropyron repens (L.) Beauv.] leaves and rhizomes that were incubated in soils for 0, 1, 2, 4, and 6 weeks. Alfalfa (Medicago sativa L.) seeds were grown for 96 h in water, water extracts of control soils, and water extracts of soil with quackgrass rhizomes or leaves. Dried quackgrass rhizomes and leaves contained water-soluble toxins that inhibited alfalfa seedling development and growth. There was a strong interaction between incubation time and temperature on the development of additional toxins by decomposing quackgrass. High incubation temperature (30 C) accelerated toxin formation and ultimate decay. Intermediate temperature (20 C) delayed toxin formation and decay. Low incubation temperatures (5 C and 10 C) prevented formation of additional toxin. In all extracts of quackgrass and soil that had been incubated for 6 weeks, normal alfalfa seedling number equaled that in water. However, seedling growth varied with incubation temperatures.Treatment of quackgrass with glyphosate [N-(phosphonomethyl) glycine] in the greenhouse did not influence the toxicity of decaying quackgrass leaves. The highest toxic effect was noted after 1 week of decay on the soil surface.

Thermal and water source effects upon the stability of enteroviruses in surface freshwaters

1989 ◽  
Vol 35 (4) ◽  
pp. 474-480 ◽  
Author(s):  
Christon J. Hurst ◽  
William H. Benton ◽  
Kim A. McClellan
Keyword(s):  
Bacterial Growth ◽  
Incubation Temperature ◽  
Water Source ◽  
Inactivation Rate ◽  
Human Enterovirus ◽  
Strongly Correlated ◽  
Artificial Lake ◽  
Viral Inactivation ◽  
Term Survival ◽  
Incubation Temperatures

The long-term survival of three human enterovirus serotypes, Coxsackievirus B3, echovirus 7, and poliovirus 1 was examined in samples of surface freshwater collected from five sites of physically different character. These were an artificial lake created by damming a creek, a small groundwater outlet pond, both a large- and a medium-sized river, and a small suburban creek. Survival was studied at temperatures of −20, 1, and 22 °C. The average amount of viral inactivation was 6.50–7.0 log10 units over 8 weeks at 22 °C, 4–5 log10 units over 12 weeks at 1 °C, and 0.4–0.8 log10 units over 12 weeks at −20 °C. The effect of incubation temperature upon viral inactivation rate was statistically significant (p < 0.00001). As determined by pairing tests, survival was also significantly related to both viral serotype and water source at each of the three incubation temperatures (p ≤ 0.05). Efforts were made to determine whether the rate of viral inactivation observed at the different incubation temperatures was related to characteristics inherent to the water that was collected from the different locations. The characteristics examined included physical and chemical parameters, indigenous bacterial counts, and the amount of bacterial growth that the waters would support (measured as the maximum number of generations which seeded bacteria could undergo after being placed into either pasteurized or sterile-filtered water samples). Analysis of viral inactivation rate versus these characteristics revealed three apparent effectors of viral persistence. These were (i) hardness and conductivity, both of which strongly correlated with one another; (ii) turbidity and suspended solids content, both of which strongly correlated with one another; and (iii) the number of generations of bacterial growth that a sample was capable of supporting, which also correlated with hardness and conductivity.Key words: virus, survival, inactivation rate, water.

Nest temperature´s influence on morphology of Dermochelys coriacea hatchlings incubated in hatcheries in Oaxaca, Mexico

2021 ◽  
Author(s):  
Jesús García-Grajales ◽  
Juan Francisco Meraz ◽  
José Luis Arcos García ◽  
Eustacio Ramírez Méndez
Keyword(s):  
Incubation Temperature ◽  
Carapace Width ◽  
Principal Component ◽  
Dermochelys Coriacea ◽  
Egg Mass ◽  
Natural Environments ◽  
Data Logger ◽  
Geometric Morphometric ◽  
Low Weight ◽  
Incubation Temperatures

The influence of nest incubation temperatures on the carapace shape and morphological traits of Dermochelys coriacea (Vandelli 1761) hatchlings incubated in two hatcheries of Oaxaca, Mexico was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers without association with universities, that protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; later, hatchlings were weighed and their bodies were measured. The mean temperature of 12 nests in each hatchery were recorded, with no significant differences between hatcheries. The principal component analysis (PCA) revealed an overlapping of the carapace shape under different duration of temperature. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low weight, smaller appendage; narrower carapace width and shorter flippers length. Lower mean incubation temperatures produced hatchlings that had greater weight, greater appendage width, wider carapace width and longer flipper length. Results indicate that the D. coriacea hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.

scholarly journals Pectinase production by Aspergillus niger isolated from decomposed apple skin

2013 ◽  
Vol 48 (1) ◽  
pp. 25-32 ◽  
Author(s):  
S Islam ◽  
B Feroza ◽  
AKMR Alam ◽  
S Begum
Keyword(s):  
Aspergillus Niger ◽  
Incubation Temperature ◽  
Nitrogen Sources ◽  
Inoculum Size ◽  
Point Of View ◽  
Media Composition ◽  
Maximal Level ◽  
Pectinolytic Activity ◽  
Pectinase Activity ◽  
Pectinase Production

Pectinase activity among twelve different fungal strains, Aspergillus niger IM09 was identified as a potential one to produce maximal level 831 U/g at pH 4.0. Media composition, incubation temperature, incubation time, substrate concentration, aeration, inoculum size, assay temperature and nitrogen sources were found to effect pectinase activity. Moisture content did not affect the activity significantly. Media composition was varied to optimize the enzyme production in solid state fermentation. It was observed that the highest pectinase activity of 831.0 U/g was found to produce in presence of yeast extract as a nitrogen source in combination with ammonium sulfate in assay media. Aeration showed positive significant effects on pectinase production 755 U/g at 1000 ml flasks. The highest pectinase production was found at 2 g pectin (521 U/g) used as a substrate. Pectinolytic activity was found to have undergone catabolite repression with higher pectin concentration (205 U/g at 5 g pectin). The incubation period to achieve maximum pectinase activity by the isolated strain Aspergillus niger IM09 was 3 days, which is suitable from the commercial point of view. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15410 Bangladesh J. Sci. Ind. Res. 48(1), 25-32, 2013

scholarly journals Quality aspects of pepino dulce fruits in distinct ripening stages, packaging forms and storage conditions

2020 ◽  
Vol 23 ◽  
Author(s):  
Neide Botrel ◽  
Raphael Augusto de Castro e Melo
Keyword(s):  
Fruit Quality ◽  
Block Design ◽  
Titratable Acidity ◽  
Storage Conditions ◽  
Matter Content ◽  
Soluble Solids ◽  
Small Scale ◽  
Dry Matter Content ◽  
Ripening Stages ◽  
Quality Aspects

Abstract Pepino dulce (Solanum muricatum Aiton) or Pepino has been growing to produce edible, juicy and attractive fruits. The imported fruits and national small scale of Pepino dulce production are currently stored and commercialized under the absence of postharvest handling recommendations. Therefore, this work aimed to evaluate the quality aspects of Pepino dulce fruits in distinct ripening stages, forms of packaging and conditions of storage. The trial was conducted in a 2x2x2 factorial scheme - 2 ripening stages (ripe and immature) x 2 forms of packaging (with and without wrapping in plastic film) x 2 conditions of storage (room: 25 °C ± 2 ºC and 57% ± 5% of relative humidity (RH); cold: under refrigeration 10 °C ± 2 °C and 85% ± 5% of RH) – in a complete randomized block design. Fruit quality attributes, such as vitamin C, chemical and phenolic content, fruit color (mesocarp), firmness, dry matter content, total titratable acidity (TA), total soluble solids and pH, were evaluated. Fruits showed a centesimal composition with low calories and a significant content of potassium (K), phosphorus (P) and magnesium (Mg), which can contribute to the daily supply of these elements. For commercialization purposes, the association of packaging (plastic wrapping film) and refrigerated storage (cold: 10 °C ± 2 °C and 85% ± 5% of RH) to maintain the characteristics of fruit quality after a 15 days period is more important than its individual use.

scholarly journals Inhibitory Effect of Flusilazole on the Spore Formation of Aspergillus niger Causing the Onion Black Mold in Vapour Phase

2002 ◽  
Vol 8 (2) ◽  
pp. 124-130
Author(s):  
Heung-Tae Kim ◽  
Se-Won Park ◽  
Gyung-Ja Choi ◽  
Jin-Cheol Kim ◽  
Kwang-Yun Cho
Keyword(s):  
Aspergillus Niger ◽  
Vapour Phase ◽  
Inhibitory Effect ◽  
Spore Formation ◽  
Black Mold

scholarly journals Development of spiced squash (appetizer) from wild prickly pear (Opuntia dillenii Haw.) and its quality evaluation during storage

2019 ◽  
Vol 11 (2) ◽  
pp. 315-320
Author(s):  
Monika Chauhan ◽  
N S Thakur ◽  
Abhimanyu Thakur
Keyword(s):  
Quality Evaluation ◽  
Value Added ◽  
Storage Conditions ◽  
Quality Parameters ◽  
Prickly Pear ◽  
Soluble Solids ◽  
Temperature Conditions ◽  
Wild Fruit ◽  
Polyethylene Terephthalate Bottles ◽  
Opuntia Dillenii

Wild prickly pear (Opuntia dillenii Haw.) is one of the wild fruit with great importance because of its high antioxidants, colour pigments and other quality parameters besides its medicinal properties. In India, there are only a limited number of reports pertaining to utilization of this fruit which further lack the development of value added novel products. So, the present studies were carried out for the development of spiced squash or appetizer from wild prickly pear fruit and its quality evaluation during storage. Different combinations of fruit juice (25, 30, 35 and 40 %) and sugar syrup (40 and 45 °B) were tried to standardize a proper combination for appetizer. The appetizer prepared by using the best recipe with 35 % juice, 45 °B TSS (Total soluble solids) and 1.20 % acidity was packed in two packaging materials viz. glass and PET (Polyethylene terephthalate) bottles which were further stored for six months under ambient and refrigerated temperature conditions. Appetizer packed in glass as well as in PET packaging material can be stored successfully for a period of six months under both the temperature conditions. However, various quality parameters of appetizer were retained higher in glass bottles stored under refrigerated storage conditions.

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