共生菌Cardinium对朱砂叶螨的生殖调控作用

为了了解共生菌Cardinium对朱砂叶螨Tetranychus cinnabarinus (Boisduval)的生殖调控作用,从检测到感染Cardinium的种群中选取山西运城和甘肃兰州2个感染率较高的种群作为实验材料,对Cardinium在寄主生殖调控方面的作用进行研究。通过人工培养100%感染Cardinium的种群和100%不感染的种群,并从中挑取不同感染类型的雌雄螨单独进行杂交实验,设立感染Cardinium(♀)×感染Cardinium(♂),感染Cardinium(♀)×不感染(♂),不感染(♀)×感染Cardinium(♂),不感染(♀)×不感染(♂) 4种杂交组合。结果发现,抗生素处理后不感染的雌螨和受感染雄螨的交配表现出了单向的胞质不亲和,而且2个种群表现出了2种类型：在山西种群不亲和的组合中,CI表现为卵孵化率显著降低,多数雌螨都产生出F₁雌螨后代,但是F₁代雌螨数量相对于其他3种组合明显减少; 而在甘肃种群不亲和的组合中则表现为卵全部孵化且幼螨100%存活,但全部为雄螨后代。2个种群中Cardinium的亲缘关系非常相近,而它们却能够在不同的地理种群中表现出不同的CI表型,这提示亲缘关系非常接近的品系也可以产生不同的表型。研究结果为深入揭示Cardinium的感染机制和生殖调控作用提供重要基础。

Manipulation of symbiont Cardinium on the reproduction of the carmine spider mite,Tetranychus cinnabarinus(Boisduval)(Acari:Tetranychidae)

To clarify the effect of Cardinium on the reproductive traits of the infected carmine spider mites, Tetranychus cinnabarinus (Boisduval), the experiments were performed in the Shanxi and Gansu populations of China to test for the cytoplasmic incompatibility (CI) phenotype previously reported to be caused by Cardinium. The infected and uninfected mites from each population were crossed with each other in the following four cross combinations: Cardinium infected ♀ × Cardinium infected ♂, Cardinium infected ♀ × uninfected ♂, uninfected ♀ × Cardinium infected ♂, uninfected ♀ × uninfected ♂. The results showed that CI was induced in both populations when the infected males were crossed with the uninfected females. Furthermore, the two populations tested showed the different types of CI. In Shanxi population, CI resulted in severe reduction in the hatchability of eggs and the number of F1 females, while in Gansu population, CI resulted in a 100% hatchability of eggs, but the F1 generation contained no female mite. The Cardinium strains in these two populations share very close relationship, but their different CI performance suggests that closely related strains may have different phenotypes of CI. Our results will be proved useful in future studies on the infection mechanism and reproductive manipulation of Cardinium.