Influence of irradiation on sperm ultrastructure and fertility of apriona germari (coleoptera: cerambycidae)

In order to further clarify the radiation sterility mechanism of Apriona germari, influence of irradiation with Gamma ray on sperm ultrastructure and fertility of A. germari were studied at dose of 20, 40, 80, 120 and 160 Gy. The results showed the natural seminal vesicle contained 256 sperms in A. germari. The sperm head with no acrosome is mainly made up with nucleus, and its tail had mitochondrial derivatives, accessory bodies and a 9 + 9 + 2 axoneme. The conglutination of sperms from irradiated A. germari was observed, the conglutination percentage was 66.67± 5.78% at dose of 40 Gy and it reached 100% when the dose increased to 160 Gy. The sperm nucleus diameter swelled up clearly in low dose of 40 Gy, significantly higher than the control, while the irradiation of 160 Gy led to additional 1 times spermatid division, a single vesicle with 512 sperms, and sperm cells volume decreased significantly. When the females irradiated with 40 Gy were coupled with irradiated males, the fertility was the minimum. When the irradiated females coupled with natural males and the natural females coupled with irradiated males, their fertility was also lower than the control at different irradiation dose. The optimal dose of radiation sterility of A. germari was determined to be 40 Gy by comprehensive analysis. (authors)