空间飞行和^(60)Co-γ射线辐照对苦荬菜种子的细胞学效应研究

Cytological Effects of Aerospace Flight and ^(60)Co-γ-Rays Irradiation on the Seeds of Lactuca indica L

利用返回式卫星搭载苦荬菜(Lactucaindica)干种子,研究比较其与用不同剂量γ射线辐照对苦荬菜根尖细胞的遗传学效应。实验结果表明:与地面对照组相比,种子空间飞行可促进根尖细胞有丝分裂;而γ射线则抑制根尖细胞有丝分裂,并随着辐照剂量的增加有丝分裂指数逐步下降。二者均可诱发根尖细胞产生微核、染色体断裂、染色体粘连、落后染色体、游离染色体、桥等畸变。但空间飞行诱发畸变的频率明显低于γ射线辐照。在γ射线辐照剂量0～30Gy范围内,随着剂量的增加,单微核、多微核和染色体总畸变频率逐步升高。

The experiment was carried out to compare the cytological effects induced by aerospace and ^60Co-γ-rays irradiation on the root tip cells of Lactuca indica L. seeds treated by recoverable satellite and irradiation at different dose ^60Co-γ-rays in the range from 0 to 30Gy, respectively. The results show that aerospace flight stimulated the cell mitosis, but ^60Co-γ-rays irradiation inhibited cell mitosis. With the increased dosage of ^60Co-γ-rays irradiation, mitosis rate decreased. 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 applied, the higher rates of single micronucleus,mutil-micronucleus, and total chromosome aberration occurred.