scholarly journals Effects of Genotype and Date of Harvest on Infection of Peanut Seed by Aspergillus flavus and Subsequent Contamination with Aflatoxin1

1986 ◽  
Vol 13 (2) ◽  
pp. 46-50 ◽  
Author(s):  
V. K. Mehan ◽  
D. McDonald ◽  
N. Ramakrishna ◽  
J. H. Williams
Keyword(s):  
Aspergillus Flavus ◽  
Field Trials ◽  
Aflatoxin Contamination ◽  
The Other ◽  
Seed Infection ◽  
Peanut Seed ◽  
Aflatoxin Content ◽  
Peanut Crop ◽  
Increased Susceptibility

Abstract Several peanut genotypes reported as resistant, susceptible or highly susceptible to in vitro colonization of rehydrated, mature, stored, undamaged seed by Aspergillus flavus (IVSCAF) were tested for natural seed infection by A. flavus and other fungi in two or more replicated field trials at ICRISAT Center, Patancheru, India, in 1979–1984. Undamaged pods were sampled before maturity, at optimum maturity (normal harvest) and when over - mature (late harvest) and seed examined for infection by A. flavus and other fungi. In the 1983 and 1984 rainy and 1983/84 postrainy seasons, only four genotypes (one resistant and three susceptible) were tested, and seed were also tested for aflatoxin content. In all seasons the genotypes reported as IVSCAF - resistant had significantly lower levels of seed infection with A. flavus and other fungi than did genotypes reported as IVSCAF - susceptible. Cenotypic differences in levels of seed infection by A. flavus were consistent over seasons. The resistant cultivar J11 had a significantly lower aflatoxin content than the other three IVSCAF - susceptible genotypes tested in the 1983–1984 seasons. Drought stress in the 1984 season apparently increased susceptibility to seed infection by A. flavus and other fungi, and to aflatoxin contamination, in all cultivars. Seed infection by A. flavus and other fungi, and aflatoxin contamination increased with increasing maturity of pods, indicating the importance of lifting the peanut crop at optimum maturity.

scholarly journals Resistance of Peanut Genotypes to Seed Infection by Aspergillus Flavus in Field Trials in India1

1987 ◽  
Vol 14 (1) ◽  
pp. 17-21 ◽  
Author(s):  
V. K. Mehan ◽  
D. McDonald ◽  
K. Rajagopalan
Keyword(s):  
Aspergillus Flavus ◽  
Macrophomina Phaseolina ◽  
Field Trials ◽  
Field Resistance ◽  
Aflatoxin Contamination ◽  
Seed Infection ◽  
Seed Colonization ◽  
Positive Correlations ◽  
Resistant Genotypes

Abstract Eleven peanut genotypes, six resistant and five susceptible to in vitro seed colonization by Aspergillus flavus Link (IVSCAF), were evaluated for field resistance to seed infection by A. flavus and other soil fungi, and for aflatoxin contamination, in seven environments in southern India. Five of the IVSCAF-resistant genotypes had significantly greater resistance to infection of seed by A. flavus in the field and had lower aflatoxin contamination than the IVSCAF-susceptible genotypes. Resistance to field infection of seed by A. flavus was stable across the seven environments. Significant interactions were found between environments and IVSCAF-susceptible genotypes for infection by A. flavus, Aspergillus niger van Tiegh, and Macrophomina phaseolina (Tassi.) Goid. Genotypes with field resistance to A. flavus also had significantly less seed infection by A. niger, M. phaseolina, and Fusarium spp. than had the A. flavus-susceptible genotypes. Significant positive correlations were found between IVSCAF-resistance and field resistance to A. flavus seed infection, and between the seed infection and aflatoxin B1 contamination. The field resistant genotypes J 11, Ah 7223, UF 71513, U 4–7–47 have yield levels and pod and seed characters acceptable in India.

A Phytoalexin and Aflatoxin Producing Peanut Seed Culture System

1994 ◽  
Vol 21 (2) ◽  
pp. 130-134 ◽  
Author(s):  
S. M. Basha ◽  
R. J. Cole ◽  
S. K. Pancholy
Keyword(s):  
Water Stress ◽  
Culture System ◽  
Fungal Growth ◽  
Aflatoxin Contamination ◽  
Peanut Seed ◽  
Seed Culture ◽  
Murashige And Skoog Medium ◽  
Yellow Orange ◽  
Increased Susceptibility

Abstract An in vitro seed culture system was established to grow peanut seed of different maturities viz. white, yellow, orange, brown and black, using a modified Murashige and Skoog medium. Under this system peanut seed of yellow, orange, brown and black maturity categories grew to maturity as measured by increase in their size and germinability. In vitro cultured seeds produced significant amounts of phytoalexins and were contaminated with aflatoxins following their inoculation with Aspergillus spp. while the noninoculated sterile controls did not produce any phytoalexins. Exposure of seed cultures to water stress using various concentrations of mannitol (0 to 1 M) and polyethylene glycol 8000 (0-30% w/v) caused a significant decrease in their phytoalexin producing ability, and enhanced fungal growth compared to the nonstressed controls. The seeds that were stressed with mannitol and subsequently inoculated with A. flavus and A. parasiticus showed a significant increase in the aflatoxin contamination of stressed seed compared to the unstressed control. This would indicate that in vitro grown seeds responded to water stress similar to the field grown peanuts by loosing their ability to produce phytoalexins and increased susceptibility to aflatoxin contamination. Hence, this system has a potential application in evaluating peanut genotypes for aflatoxin resistance under water stress.

scholarly journals Effect of Irrigation Interval, Planting Date, and Cultivar on Aspergillus flavus and Aflatoxin Contamination of Peanut in a Sandy Soil of Niger

2003 ◽  
Vol 30 (2) ◽  
pp. 79-84 ◽  
Author(s):  
F. Waliyar ◽  
A. Traoré ◽  
D. Fatondji ◽  
B. R. Ntare
Keyword(s):  
Water Stress ◽  
Aspergillus Flavus ◽  
Central Africa ◽  
Field Trials ◽  
Aflatoxin Contamination ◽  
Planting Date ◽  
Research Station ◽  
Seed Infection ◽  
Irrigation Interval ◽  
Soil Temperatures

Abstract Aflatoxin contamination of peanut is a major threat to consumers in West Africa. High levels of aflatoxin have been reported in West and Central Africa, particularly in Niger. Field trials were conducted from 1991 to 1994 at ICRISAT Sahelian Center, Sadore Research Station near Niamey, Niger. Various production practices were compared to examine their effects on water stress and Aspergillus flavus infection and aflatoxin contamination. Different levels of water stress were achieved by varying planting date and frequency of irrigation in two resistant and two susceptible cultivars. Contamination of seed with A. flavus and aflatoxin was determined. The susceptible cultivars 28–206 and JL 24 had much higher levels of seed infection following 3 wk or more of water stress than did the resistant cultivars. Susceptible cultivars showed up to 81% seed infection. Cultivar 28–206 had low levels of contamination when there was low water stress but became very susceptible when the period of water stress increased (3 wk of drought). Seed infection by A. flavus and contamination by aflatoxin were highly correlated across years and cultivars. Although seed infection by A. flavus was very responsive to water stress in the field, aflatoxin contamination did not increase proportionally. This may have been influenced by high soil temperatures in Niger, which may exceed 40 C. Most reports indicate that a minimum of 20 to 30 d of drought is needed for significant aflatoxin contamination, but contamination was observed after 14 d of water stress in this study.

scholarly journals A Novel Niosome-Encapsulated Essential Oil Formulation to Prevent Aspergillus flavus Growth and Aflatoxin Contamination of Maize Grains During Storage

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 646 ◽  
Author(s):  
García-Díaz ◽  
Patiño ◽  
Vázquez ◽  
Gil-Serna
Keyword(s):  
Aspergillus Flavus ◽  
Fungal Growth ◽  
Storage Conditions ◽  
Aflatoxin Contamination ◽  
Small Scale ◽  
Low Concentrations ◽  
Oil Formulation ◽  
Scale Test ◽  
Encapsulation Method

Aflatoxin (AF) contamination of maize is a major concern for food safety. The use of chemical fungicides is controversial, and it is necessary to develop new effective methods to control Aspergillus flavus growth and, therefore, to avoid the presence of AFs in grains. In this work, we tested in vitro the effect of six essential oils (EOs) extracted from aromatic plants. We selected those from Satureja montana and Origanum virens because they show high levels of antifungal and antitoxigenic activity at low concentrations against A. flavus. EOs are highly volatile compounds and we have developed a new niosome-based encapsulation method to extend their shelf life and activity. These new formulations have been successfully applied to reduce fungal growth and AF accumulation in maize grains in a small-scale test, as well as placing the maize into polypropylene woven bags to simulate common storage conditions. In this latter case, the antifungal properties lasted up to 75 days after the first application.

scholarly journals In Vitro Activity of Balanites aegyptiaca and Tamarindus indica Fruit Extracts on Growth and Aflatoxigenicity of Aspergillus flavus and A. parasiticus

2013 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Saifeldin Ahmed El-nagerabi ◽  
Abdulkadir E. Elshafie ◽  
Mohamed R. Elamin
Keyword(s):  
Aspergillus Flavus ◽  
Fungal Growth ◽  
Aflatoxin Contamination ◽  
Tamarindus Indica ◽  
Balanites Aegyptiaca ◽  
Total Aflatoxin ◽  
Animal Products ◽  
Fruit Extracts ◽  
Aflatoxin B

<p>Aflatoxin and especially aflatoxin B<sub>1</sub> (AFB<sub>1</sub>) is a carcinogenic secondary metabolite synthesized by certain <em>Aspergillus </em>species. They contaminate natural and processed agricultural and animal products which render them unfit for consumption. The aim of this study was to evaluate the <em>in vitro</em> effects of <em>Balanites aegyptiaca</em> and <em>Tamarindus indica</em> fruit extracts on the growth and aflatoxin secretion of <em>Aspergillus flavus</em> (SQU21) and <em>A. parasiticus </em>(CBS921.7) strains. The two fruit extracts significantly (<em>P </em>&lt; 0.05) reduced aflatoxin and did not inhibit mycelial dry weights of the two <em>Aspergillus </em>strains. At different concentrations of balanites (2.5-10%), the inhibition of total aflatoxin was 49.9-84.8% for <em>A. flavus</em> (SQU21) and 32.1-84.4% for <em>A. parasiticus</em> (CBS921.7), whereas the inhibition of aflatoxin Bwas 38.2-81.4% and 32.8-80.6% for the two strains. Tamarind fruit extract (2.5-7.5%) caused 28.8-84.2% and 40.7-85.5% reductions in total aflatoxin and 37.1-83.5% and 33.9-85.9% in aflatoxin B for the two strains, respectively. None of these extracts inhibited the fungal growth or detoxified synthetic aflatoxin B<sub>1</sub>. We have concluded that these fruits contain various inhibitors to aflatoxin biosynthesis and secretion. Therefore, they can be used in combination as safe green biopreservatives to combat aflatoxin contamination of food.</p>

Effect of Imazapic and 2,4-DB on Peanut Yield, Grade, and Seed Germination

2010 ◽  
Vol 37 (1) ◽  
pp. 78-82 ◽  
Author(s):  
W. H. Faircloth ◽  
E. P. Prostko
Keyword(s):  
Seed Germination ◽  
Tomato Spotted Wilt Virus ◽  
Seed Quality ◽  
Field Trials ◽  
The Other ◽  
Peanut Seed ◽  
Stand Establishment ◽  
South Georgia ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Abstract Recurrent problems with peanut seed germination and stand establishment have raised concerns about the potential effects of herbicides on peanut seed quality. Field trials were conducted in south Georgia in 2005 and 2006 to evaluate the effects of imazapic and 2,4-DB on peanut yield, grade, incidence of tomato spotted wilt virus (TSWV), and seed germination. Imazapic at 71 g ai ha−1, applied at 30 and 40 days after planting (DAP), and 2,4-DB at 270 g ai ha−1, applied at 75 or 90 DAP, had no effect on peanut yield, grade, incidence of TSWV, and seed germination when averaged over two locations (Dawson and Tifton) and three cultivars (Georgia Green, Georgia-01R, and C-99R). Normal cultivar yield variations were observed; however, Georgia-01R had reduced standard (25 C) and cold (15 C) germination when compared to the other cultivars.

scholarly journals The Atoxigenic Biocontrol Product Aflasafe SN01 Is a Valuable Tool to Mitigate Aflatoxin Contamination of Both Maize and Groundnut Cultivated in Senegal

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 510-520 ◽  
Author(s):  
L. A. Senghor ◽  
A. Ortega-Beltran ◽  
J. Atehnkeng ◽  
K. A. Callicott ◽  
P. J. Cotty ◽  
...  
Keyword(s):  
Open Access ◽  
Aspergillus Flavus ◽  
Large Scale ◽  
International Markets ◽  
Economic Benefits ◽  
Aflatoxin Contamination ◽  
Active Ingredients ◽  
Aflatoxin Content ◽  
Open Access Article ◽  
Aspergillus Section

Aflatoxin contamination of groundnut and maize infected by Aspergillus section Flavi fungi is common throughout Senegal. The use of biocontrol products containing atoxigenic Aspergillus flavus strains to reduce crop aflatoxin content has been successful in several regions, but no such products are available in Senegal. The biocontrol product Aflasafe SN01 was developed for use in Senegal. The four active ingredients of Aflasafe SN01 are atoxigenic A. flavus genotypes native to Senegal and distinct from active ingredients used in other biocontrol products. Efficacy tests on groundnut and maize in farmers’ fields were carried out in Senegal during the course of 5 years. Active ingredients were monitored with vegetative compatibility analyses. Significant (P < 0.05) displacement of aflatoxin producers occurred in all years, districts, and crops. In addition, crops from Aflasafe SN01-treated fields contained significantly (P < 0.05) fewer aflatoxins both at harvest and after storage. Most crops from treated fields contained aflatoxin concentrations permissible in both local and international markets. Results suggest that Aflasafe SN01 is an effective tool for aflatoxin mitigation in groundnut and maize. Large-scale use of Aflasafe SN01 should provide health, trade, and economic benefits for Senegal. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

scholarly journals Resistance to Aspergillus flavus in Corn Kernels Is Associated with a 14-kDa Protein

1998 ◽  
Vol 88 (4) ◽  
pp. 276-281 ◽  
Author(s):  
Z.-Y. Chen ◽  
R. L. Brown ◽  
A. R. Lax ◽  
B. Z. Guo ◽  
T. E. Cleveland ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Trypsin Inhibitor ◽  
Aflatoxin Contamination ◽  
Inhibitor Protein ◽  
Trypsin Activity ◽  
Terminal Sequence ◽  
High Concentration ◽  
Resistant Varieties ◽  
Corn Kernels

Corn genotypes resistant or susceptible to Aspergillus flavus were extracted for protein analysis using a pH 2.8 buffer. The profile of protein extracts revealed that a 14-kDa protein is present in relatively high concentration in kernels of seven resistant corn genotypes, but is absent or present only in low concentration in kernels of six susceptible ones. The N-terminal sequence of this 14-kDa protein showed 100% homology to a corn trypsin inhibitor. The 14-kDa protein purified from resistant varieties also demonstrated in vitro inhibition of both trypsin activity and the growth of A. flavus. This is the first demonstration of antifungal activity of a corn 14-kDa trypsin inhibitor protein. The expression of this protein among tested genotypes may be related to their difference in resistance to A. flavus infection and subsequent aflatoxin contamination.

scholarly journals Suppression of Fusarium moniliforme in Rice by Rice-Associated Antagonistic Bacteria

Plant Disease ◽  
1997 ◽  
Vol 81 (1) ◽  
pp. 49-52 ◽  
Author(s):  
A. M. Rosales ◽  
T. W. Mew
Keyword(s):  
Seed Germination ◽  
Fusarium Moniliforme ◽  
Mycelial Growth ◽  
Field Trials ◽  
The Philippines ◽  
The Other ◽  
Antagonistic Bacteria ◽  
Seedling Vigor ◽  
Bacterial Strains

The potential of antagonistic bacteria from paddy water, rhizosphere soils, sclerotia, and rice plants to control “bakanae” caused by Fusarium moniliforme was assessed. Experiments were conducted to determine the in vitro antibiosis and effect of bacteria on seed germination. Out of 441 isolates, 113 were inhibitory to mycelial growth of the pathogen. Bacterial strains were classified into three groups based on effect on seed germination: (i) those that promoted germination and enhanced seedling vigor; (ii) those that had no effect on germination; and (iii) those that were deleterious and inhibited germination. Bacterization of naturally infected seeds reduced bakanae incidence in seedbox and seedbed tests. In a seedbed experiment with IR 58 seeds soaked in suspensions of bacterial strains, bakanae incidence and disease control ranged from 0.9 to 6.8% and 71.7 to 96.3%, respectively. From the 3 years of field trials, 10 strains reduced bakanae. Five strains consistently reduced bakanae, but the other five exhibited variable effects among trials. Specificity of suppression by antagonistic bacteria against different pathogenic isolates of F. moniliforme from various locations in the Philippines was observed.

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