<正> The effects of superconducting static magnetic fields(SMFs)on the pollen mothercells(PMCs)of wheat were investigated in order to evaluate the possible genotoxic effect of suchnon-ionizing radiation.The seeds of wheat were exposed to static magnetic fields with eitherdifferent magnetic flux densities(0,1,3,5 and 7 Tesla)for 5 h or different durations(1,3 and5 h)at a magnetic flux density of 7 Tesla.The seeds were germinated at 23~C after exposure andthe seedlings were transplanted into the field.The PMCs from young wheat ears were taken andslides were made following the conventional method.The genotoxic effect was evaluated in terms ofmicronucleus(MN),chromosomal bridge,lagging chromosome and fragments in PMCs.Althoughthe exposed groups of a low field intensity(below 5 Tesla)showed no statistically significantdifference in the aberration frequency compared with the unexposed control groups and shamexposed groups,a significant increase in the chromosomal bridge,lagging chromosome,triple-polarsegregation or micronucleus was observed at a field strength of 5 Tesla or 7 Tesla,respectively.The analysis of dose-effect relationships indicated that the increased frequency of meiotic abnormalcells correlated with the flux density of the magnetic field and duration,but no linear relationshipwas observed.Such statistically significant differences indicated a potential genotoxic effect ofhigh static magnetic fields above 5 T.
