柑桔大实蝇辐射不育机理的研究

本文研究了柑桔大实蝇蛹的发育,生殖系统和生殖细胞的发生及辐射对卵子、精子及其超微结构的影响。后期蛹体细胞分化发育完成时,卵子尚处于卵原囊期,雄虫已形成大量成熟精子。用9krad照射后期蛹,不影响成虫的活动和交尾竞争能力,但可导致大实蝇不育。大实蝇染色体数目为2n=12,总长度56.2μm,长度变异范围6.52～1.10μm,属中等非对称核型。辐照后引起染色体断裂而导致缺损、多着丝点环等畸变,使细胞分裂受阻引起不育。唾腺及肠细胞辐照以后24小时DNA含量明显下降,但能逐步修复。

STUDIES ON THE MECHANISM OF RADIATION-INDUCED STERILITY OF CHINESE CITRUS FLY, DACUS CITRI [DIP.:TEPHRITIDAE]

This paper deals with studies on the pupal development, morphology of the reproductive system, genesis of the germ cells and impact of radiation on the structure of egg and sperm of the Chinese citrus fly (CCF), Dacus citri. The development of somatic cells completed in the late pupal stage, while eggs were in the germarial cyst of the female pupae and many sperms formed in the males. Exposure of matured pupae to 9 Krad gamma-ray did not affect the adult activity and mating capability but induced full sterility. It is suggested that the late pupal stage is the optimum irradiating period and 9 Krad is an appropriate irradiating sterile dosage. It was found that the number of chromosomes of CCF was 2n=12. The total length of chromosome was 56.2 um, and the deviation of chromosomal length was from 6.52 to 1.10 um. The Karyotype was not symmetric. Content of DNA in salivary gland and larval intestinal cells of CCF declined 24 hr. after irradiation but recovered gradually.