Document Type : Plant Pathology
Authors
Abstract
Ear rot of corn caused by Fusarium species could create an overall comprehensive problem. Fusarium species can produce mycotoxins such as trichothecenes which threat the human's health. Cultivation of maize in Moqhan region was about 10000 hectares. Forty (5-10 Kg) samples each including 10 subsamples of corn ears collected at harvest time, kernels separated from the ears, dried and divided into two parts: one part for mycological studies and another part for toxicology studies. The media Nash-Snyder, PDA and Czapek were used for isolation, and PDA and CLA for identification. Deoxynivalenol detection and measurement of the corn samples were carried out using IAC - HPLC (High Performance Liquid Chromatography and immunoaffinity Columns). To study the potential of deoxynivalenol production of theisolates, ten isolates (two of each species) were selected as the representative of each species, the potential of DON production for each isolate was measured after one week incubation at 25-27ºC and two weeks at 12ºC alternatively. To ensure the deoxynivalenol production of the two F. proliferatum isolates, these isolates inoculated artificially in corn ears and after 10 days the amount of DON was detected in the grains. Fusarium species and the frequency of isolation were F. verticillioides, 47.65%;
F. proliferatum, 33.873%, 15.33%; F. nygamai, 4.86%; F. oxysporum ,3.06 . Deoxynivalenol was detected in 45% of the samples. The total mean of contamination was 45% and the range of contamination was 59.4 – 542.55ng/g with the mean of 95.30. ng/g. Among the Fusarium species isolates two isolates of F. proliferatum could produce DON in artificial conditions.
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