Institute of General Genetics, USSR Academy of Sciences, Moscow, USSR
Abstract:
The effect of weightlessness on chromosomal aberration frequency in preflight irradiated seeds, on the viability, fertility and mutation frequency in , and on the frequency of nondisjunction and loss of X chromosomes in preflight irradiated gametes was studied aboard the Salyut 6 orbital station. The following effects were observed: a flight-time dependent amplification of the effects of preflight -irradiation in . with respect to all the parameters studied; unequal effects in seeds and seedlings of ; and a significant increase in the frequency of nondisjunction and loss of chromosomes during meiosis in females. These observations are discussed in terms of the data of ground-based model experiments and flight experiments with a different time of exposure of objects to weightlessness. An attempt is made to elucidate the role of weightlessness in the modification of ionizing radiation effects.