title: Molecular characterization of aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates collected from corn grains.
abstract: Twelve species from six fungal genera were found to be associated with corn (Zea mays L.) grain samples collected from three main regions of Saudi Arabia. The average frequencies of the most common genera were Aspergillus (11.4%), Fusarium (9.5%), Penicillium (5.1%), and Alternaria (5.8%). Fifteen isolates of Aspergillus flavus were screened by HPLC for their ability to produce aflatoxins (AF). The percentage of aflatoxigenic A. flavus isolates was 53%. Eight isolates produced AF, at concentrations ranging 0.7-2.9 ppb. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers were used to genetically characterize isolates of A. flavus and to discriminate between the aflatoxigenic and non-aflatoxigenic isolates. RAPD and ISSR analysis revealed a high level of genetic diversity in the A. flavus population, which was useful for genetic characterization. The clustering in the RAPD and ISSR dendrograms obtained was unrelated to geographic origin. The RAPD and ISSR markers could not discriminate between aflatoxigenic and non-aflatoxigenic isolates, but the ISSR primers were somewhat better.
authors.affiliation: Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt.
authors.forename: M A
authors.initials: MA
authors.lastname: Mahmoud
authors.affiliation: Botany and Microbiology Department, College of Science.
authors.forename: H M
authors.initials: HM
authors.lastname: Ali
authors.affiliation: Botany and Microbiology Department, College of Science, aabdelaziz@ksu.edu.sa.
authors.forename: A R M
authors.initials: AR
authors.lastname: El-Aziz
authors.affiliation: Botany and Microbiology Department, College of Science.
authors.forename: M R
authors.initials: MR
authors.lastname: Al-Othman
authors.affiliation: Botany and Microbiology Department, College of Science.
authors.forename: A S
authors.initials: AS
authors.lastname: Al-Wadai
mesh_terms: D000348:Aflatoxins / Q000633:toxicity*; D001231:Aspergillus flavus / Q000235:genetics* / Q000302:isolation & purification* / Q000528:radiation effects; D017931:DNA Primers / Q000378:metabolism; D005843:Geography; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D012529:Saudi Arabia; D012639:Seeds / Q000382:microbiology*; D013048:Specimen Handling; D014466:Ultraviolet Rays; D003313:Zea mays / Q000382:microbiology*
chemical_list: D000348:Aflatoxins; D017931:DNA Primers