DISTRIBUTION PATTERNS OF CHROMATID ABERRATIONS INDUCED BY MH-TREATMENT IN VICIA-FABA L SEEDS AS AFFECTED BY EXPERIMENTAL STORAGE

Seed storage at 50% or 20% water content subsequent to MH treatment of Vicia faba root tip meristem cells leads to a decrease or increase, r espectively, of the frequency of CAs. Deeper insight into the distribu tion patterns of chromatid aberrations observed in these experiments a nd available from the use of the reconstructed ACB-karyotype of Vicia faba show that significant changes during storage as to the frequency of induced chromatid aberrations have no significant influence on the percentage of chromatid aberrations located in the particular chromoso me segments. It can be stated that, although at 50% water content stor age the frequency of damaged cells decreases, the distribution pattern of the chromatid aberrations remains basically uninfluenced. The same is true in the case of 20% water content storage when the frequency o f damaged cells increases. Since the distribution pattern of the chrom atid aberrations was in both cases (decrease vs. increase) non-random, a possible explanation is that while the DNA damage is selective and some segments are preferentially involved, the repair of this DNA dama ge is not selective for a particular chromosome or segment of the chro mosome.