辐照对桑天牛精子超微结构及生育力的影响

Influence of Irradiation on Sperm Ultrastructure and Fertility of Apriona germari(Coleoptera: Cerambycidae)

为进一步明确桑天牛辐照不育机制,研究了桑天牛雄虫在20、40、80、120和160Gy的γ射线辐照下其精子超微结构及其生育力的影响。结果表明,健康桑天牛精囊内具有256个成熟精子。精子头部主要是精核,无顶鞘,尾部含线粒体衍生物、附体及9+9+2型的微管系统。受辐照的桑天牛精子间发生粘连现象,在20Gy下粘连百分比为66.67±5.78%,当剂量升高到160Gy时,其比例达到100%。精核直径在40Gy的剂量下膨胀最大,显著高于对照;而160Gy的剂量导致精细胞分裂增加1次,单个精囊内具有512个精子,精子细胞体积显著减小。经40Gy辐照的雌虫与辐照雄虫交尾的桑天牛生育力最低。在其他不同辐照剂量下,辐照雌虫与健康雄虫交尾及健康雌虫与辐照雄虫交尾的生育力也均低于对照。综合分析确定桑天牛成虫辐照不育的最适剂量为40Gy。本研究为开发桑天牛物理控制技术提供了参考,对农林经济的可持续发展意义远大。

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 160Gy. 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 mitoehondrial 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 40Gy and it reached 100% when the dose increased to 160Gy. The sperm nucleus diameter swelled up clearly in low dose of 40Gy, significantly higher than the control, while the irradiation of 160Gy led to additional 1 times spermatid division, a single vesicle with 512 sperms, and sperm cells volume decreased significantly. When the females irradiated with 40Gy 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 40Gy by comprehensive analysis.