Abstract
Based on the cytological and molecular studies, types and frequency of chromosomal aberrations during meiotic division of wheat plants treated with different concentrations of deoxynivalenol (DON) were investigated. The common types of abnormalities that have been recorded were stickiness, outside, laggards, bridges, fragments, unequal division, as well as multipolar and micro- nucleated cells. Regarding the first meiotic division, the percentage of abnormal cells detected from untreated plants was 2.12% however, plants treated with 5, 10, 15, 20 and 25μg/ml DON revealed 3.73, 6.62, 6.78, 9.23 and 8.18% of abnormalities, respectively. In the second meiotic division, control plants exhibit 2.69% of abnormalities while, 2.29, 4.34, 4.23, 5.59, 4.46% of abnormal cells were detected from plants treated with 5, 10, 15, 20 and 25μg/ml DON, respectively. These results demonstrate the significant effect of treatment with DON on the total percentage of irregularities during meiosis. DNA amplification patterns of wheat plants treated with DON using two RAPD primers revealed some variations in the DNA profiles within the examined samples as compared with the control. Such variations include band intensity and appearance of novel bands or disappearance of others. The polymorphism of the detected DNA fragments particularly the absence of a number of fragments in some plants treated with different concentrations of DON suggested that contaminated wheat grains with this toxin or mycotoxigenic fungi might induce DNA rearrangements, deletions and/or changes in the DNA sequence that lead to the observed changes.
