^（60）Coγ射线辐照对柑桔大实蝇（Daccus citri）染色体影响的研究

THE EFFECT OF 60Co-GAMMAIRRADIATION ON THE CHROMOSOMES OF CHINESE CITRUS FLY

本文研究了柑桔大实蝇的染色体及６０Ｃｏγ射线对染色体的影响。染色体数目为２ｎ＝１２，总长度５６．２μｍ，长度变异范围６。５２～１．１０μｍ，核型公式为２ｎ＝４ｍ＋１ｓｍ＋Ｉｔ，属中等非对称核型。蛹期经４．５、９、１２ｋｒａｄ辐照，引起生殖细胞染色体断裂、粘逆，导致染色体缺失、易位、倒位等畸变，使细胞分裂受阻，引起配子死亡或不育。

Amorphological comparison study between the normal chromosome group and dis -torted by 60Co γ irradiation of Chinese citrus fly Dacus citri(Chen)was conducted.The chro-mosome nunlber was 2n=12,the total chromosome length was 56.2μm,the indivlduallengths of chromosomes ranged from 6.52～1.10μm,and the karyotypic formula, 2n=4m+lsm+1t,belonged to medium asymmetric type. After 4.5,9 and 12 krad of irradiation tothe pupae,the chromosomes in reproductive cell were broken and adhered each other;Chro-mosomal defciency.translocation and reversion was caused and the cell division was ob-structed. The gametes were sterilized and even diet out.