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Razzaghi-Abyaneh M, Shams-Ghahfarokhi M, Allameh A, Kazeroon-Shiri A,
Ranjbar-Bahadori S, Mirzahoseini H, Rezaee MB.
A survey on distribution of Aspergillus section Flavi in
corn field soils in Iran: population patterns based on
aflatoxins, cyclopiazonic acid and sclerotia production.
Mycopathologia. 2006 Mar;161(3):183-92
Department of Mycology, Pasteur Institute of Iran, Tehran.
mrab442@yahoo.com
Soil isolates of Aspergillus section Flavi from Mazandaran and
Semnan provinces with totally different climatic conditions in
Iran were examined for aflatoxins (AFs; B and G types),
cyclopiazonic acid (CPA) and sclerotia production. A total of 66
Aspergillus flavus group strains were identified from three
species viz. Aspergillus flavus, Aspergillus parasiticus and
Aspergillus nomius in both locations. A. flavus (87.9%) was
found to be the prominent species followed by A. nomius (9.1%)
and A. parasiticus (3.0%). Only 27.5% of A. flavus isolates were
aflatoxigenic (B(1) or B(1) and B(2)), out of which
approximately 75% were capable to producing cyclopiazonic acid
(CPA). All the A. parasiticus and A. nomius isolates produced
AFs of both B (B(1) and B(2)) and G (G(1) and G(2)) types, but
did not produce cyclopiazonic acid (CPA). Sclerotia production
was observed in only 4 isolates of A. flavus among all 66
isolates from three identified species. A. flavus isolates were
classified into various chemotypes based on the ability to
produce aflatoxins and cyclopiazonic acid (CPA). In this study,
a new naturally occurring toxigenic A. flavus chemotype
comprising of two strains capable of producing more AFB(2) than
AFB(1) has been identified. A relatively larger proportion of
aflatoxigenic A. flavus strains were isolated from corn field
soils of Mazandaran province which indicate a possible
relationship between high levels of relative humidity and the
incidence of aflatoxin-producing fungi. The importance of
incidence of Aspergillus section Flavi in corn field soils
regard to their mycotoxin production profiles and crop
contamination with special reference to climatic conditions is
discussed.
PMID: 16482391
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