Determination of aspergillus spp. producing aflatoxin contamination in pistachio nut (Pictacia vera L.)

Pistachio (Pictacia vera L.) has an important market value in Turkey?s economy. Aspergillus species synthesize aflotoxins that contaminate pistachio nuts, and reduce fruit quality. There is no detailed information on Aspergillus infection time, population of Aspergillus spp. during pre-harvest, processing and storage. Aspergillus species producing aflatoxins in the group of Flavi of Aspergillus genus on P. vera was determined. In this study Aspergillus flavus and Aspergillus parasiticus, both belonging to Flavi group as main aflatoxin producing species, were investigated.Anaylses of the collected samples that Aspergillus population was low on pistachio from flowering to pre-harvest period, and the population increases during harvest and storage. A. flavus was densely isolated from Şanlıurfa and Adıyaman provinces. Besides, A. flavus and A. parasiticus were characterized through PCR-RFLP methods. It was determined that 34 of isolates were A. flavus, 1 of the isolate was A. parasiticus according to aflR gene region. However ITS region was not efficient for differentiating these two species.When the results were compared, aflR gene region was found to be more accurate than of ITS in distinguishing A. flavus and A. parasticus.Key Words: Pictacia vera L., Aspergillus parasticus, Aspergillus flavus, PCRRFLP, Aflatoxin