[Genetic effects in plant populations in the zone of the Chernobyl accident].

During 6 years, starting from 1986, the monitoring of the dynamics of the frequency of embryo lethal and of chlorophyll mutations was carried out in arabidopsis populations in areas with different levels of radioactive contamination by the Muller embryo-test in the 30 km of ChNPP. The dose rate of chronic irradiation in the examined areas varied from 0.014 to 17 nA/Kg.

[Genetic effects in populations of plants growing in the zone of Kyshtym and Chernobyl accidents].

Studies to analyze the genetic processes in natural populations of plants were started on the territory of the East-Ural Radioactive Trace (EURT) in 1962 and in the zone of the Chernobyl accident in May 1986. The main directions of the genetic studies in both radioactive areas were similar: 1) study of the mutation process intensity depending on the dose and dose rate and analysis of dose-effect relationships for different genetic changes (point mutations, chromosome aberrations in mitosis and meiosis) in irradiated plant populations; 2) study of the mutation process dynamics in generations of chronically (prolongly) irradiated populations of plants; 3) analysis of microevolutionary processes in irradiated plant populations. The report presents an analysis of observed dose-effect relationships under the action of radiation on populations of Arabidopsis thaliana, Pinus sylvestris and a number of other plant species.

[The cytogenetic effects in natural populations of Crepis tectorum L. growing in the region of the eastern Urals radioactive trace].

Genetic consequences of a prolonged action of ionizing radiation were analyzed in five natural Crepis tectorum populations growing at the radioactively contaminated territory of the East-Ural radioactive track. In these populations about 40 years after the start of a chronic irradiation an increased frequency of chromosome aberrations was found out. An additional acute gamma irradiation at the dose of 20 Gy did not reveal any changes of radioresistance of the plants investigated.

[The cytogenetic effects in Crepis tectorum populations growing in Bryansk Province observed in the 7th year after the accident at the Chernobyl Atomic Electric Power Station].

Cytogenetic analysis of seedlings from the seeds of four populations of Crepis tectorum plants grown during 7 years in localities of Bryansk Province contaminated with radioactive products was carried out. The frequency of chromosome aberrations in root meristematic cells was higher than at similar dose rates within 30-km zone of the Chernobyl NPP. At the same frequency of chromosome aberrations (induced at higher dose rates) karyotypes with pronounced frequency were observed in 30-km zone of the Chernobyl NPP.

[The cytogenetic effects in natural populations of Crepis tectorum exposed to chronic irradiation in the region of the Chernobyl Atomic Electric Power Station. An analysis of the frequency of chromosome aberrations and karyotype changes in the 3rd and 4th years after the accident].

In three natural Crepis tectorum populations from 30-km zone of the Chernobyl NPP cytogenetic analysis of plant progenies was carried out. Germination capacity was not correlated with the dose rate of chronic irradiation. There was a correlation between frequency of cells with chromosome aberrations and frequency of seedlings with non-identical altered karyotype among which pericentric inversions and reciprocal translocations dominated.