Environmental impact on age-related dynamics of karyotypical instability in plants.

The dynamics of karyotypical instability of Allium fistulosum L. (Welsh onion) during aging of genetically homogenous seeds from plants grown in three different areas was studied. We analyzed the frequency of anaphase cells with chromosomal aberrations "damage", as a number of chromosomal aberrations per cell with aberrations, and germinating capacity, as an indicator of the 'toxic' influence of age. The seeds' aging was accompanied by an increase in karyotypical instability (increasing frequency of anaphases with aberrations) and with certain changes in the spectrum of chromosome aberrations. The clearest distinctions between old and young seeds were found for the frequency of anaphase cells with chromosome aberrations. The general level of karyotypical instability positively correlates with the age of the seeds. The regression coefficient (b) corresponds to the general tendency of karyotypical instability during seeds' senescence under storage. For 'good' (A), 'normal' (B) and 'bad' (C) conditions, the coefficients (b's) are b(A)=0.22, b(B)=0.46 and b(C)=0.84 (p<0.05 for C, and p<0.001 for A and B). It was found that different ecological conditions of plant vegetation strongly influence age-related dynamics of chromosomal instability in the seeds obtained from these plants. Possible mechanisms of the transgenerational impact of this effect are discussed.