الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Recovered isolates from local and imported corn grains were purified and identified on
morphological, cultural characteristics, and microscopic examination as: F. graminearum,
A. niger (An1 and An2), Penicillium sp., Rhizopus sp., Thanatephorus sp., A. flavus (Af1
and Af2), Sarocladium sp. Identification was then confirmed on molecular basis in
Genbank. Moreover, genotypic identification showed that there were 2 isolates of both A.
niger (An1 and An2) and A. flavus (Af1 and Af2).
2- The highest fungal population frequencies in local corn grains detected were; T.
cucumeris, P. crustosum, and S. strictum (about 98%), whereas the majority were related
to F. graminearum, S. strictum, and P. crustosum in imported grains. F. graminearum and
T. cucumeris had the lowest frequencies in local and imported corn grains, respectively.
3- Out of the nine identified tested isolates, only four isolates were able to produce
mycotoxins. F. graminearum and A. niger (An2) produced fumonisins at concs. 90.0 and
50.9 ppb., respectively. Aspergillus flavus (Af2) produced aflatoxin B1 at conc. 26.793
ppb, whereas A. flavus (Af1) produced sterigmatocystin at conc. 2 ppb., however, no
mycotoxins were produced by the other fungal isolates.
4- The major active components detected in the tested plant extracts were digitoxin (20.24%)
in licorice extract; cumic acid (10.94%) in turmeric; luteolin 6,8-C-diglucoside (49.56%)
in wheat bran; linoleic acid (16.49%) in doum; 3,5-dimethoxycinnamic acid (26.37%) in
taro peels; p-allylphenol (20.78%) in pomegranate peels; valproic Acid methyl β-Dribopyranoside (13.44%) in banana peels; Alph-Kaueene (25.67%) in eggplant peels; 3αFenchene and (Octadecanoic acid (11.03%, 10.34%) in sugar appl peels.
5- All the tested plant extracts exert inhibitory antitoxigenic effect against AFB1, but at
varying levels, depending on the applied plant, type and concentration of solvent. In
doum treatment, the highest AFB1 inhibition efficiency ratio (ER%, 83.040%) was
obtained by 50% methanol solvent; ethanol 25% and acetone 75% (85.645% and
85.075%) in banana peel extract; and acetone 25%, in wheat bran (79.342%).
6- Turmeric showed high AFB1 inhibitory activities (ER=90.78%) on applying ethanol 25%
as a solvent. On the other hand, acetone 75% realized the highest ER% values in taro peels
(83.828%). The highest inhibition rates (more than 90%) of pomegranate were achieved
by ethanol and acetone at conc. 25%.
7- Obtained results showed that treatment with sugar apple peels, extracted by ethanol 75%
resulted in the highest AFB1 inhibition rates ((82.22%), whereas eggplant peels extracted
by both ethanol 25% and 75%, in addition to acetone 50% and 75% gave significantly
high AFB1 inhibition values (87.791%-91.181%).
8- Significant reductions in wet and dry weight of the toxigenic A. flavus (Af2) isolate were
obtained by any of the tested plants. Differences in growth inhibition rates among the
tested plants greatly affected by the plant nature, extraction solvent and its concentration.
Thus, the highest wet and dry weight reduction rates were obtained by ethanol 25% in
doum, acetone 75% in licorice, acetone 50% in banana peels, methanol 50% in both wheat
bran and turmeric.
9- Application of taro peel extracted in ethanol 75% or methanol 75% resulted in great
reductions in fungal wet and dry weight, while the least growth weights in pomegranate
were obtained by methanol 50 %. Significant decreases in wet and dry weights were
90
achieved by acetone 50% and methanol 75% in sugar apple peels and eggplant peels,
respectively