The cytological effect of aerospace flight and ~(60)Co-γ-Rays irradiation on the seeds of Lactuca indica L.

The experiment was designed to explore the induction mechanism of aerospace and 60Co-γ-rays irradiation.Seeds of Lactuca indica L.in aerospace by recoverable satellite and irradiated by different dose 60Co-γ-rays were used to compare the cytological effects.In the range of the dose from 0 to 30Gy,experimental results showed that aerospace flight could stimulate the cell mitosis,but 60Co-γ-rays irradiation could inhibit mitosis.With the increase of 60Co-γ-rays irradiation,mitosis rate has fall.Both aerospace and 60Co-γ-rays irradiation induced various aberrations in root tip cells,such as micronucleus,chromosome fragment,chromosome conglutination,lagging chromosome,dissociative chromosome and bridge.However,the aberration rate caused by aerospace environment was lower than that caused by 60Co-γ-rays irradiation.The higher dosage of 60Co-γ-ray,the higher rate of single micronucleus、mutil-micronucleus and total chromosome aberration in 0 to 30Gy.