重金属镉胁迫对泽兰实蝇的生殖损伤及干扰作用研究

Eupatorium adenophorum Spreng, as an important exotic weed, has spread all over south-west China including Yunnan Province, Guizhou Province, Sichuan Province and Xizang autonomous region. It has resulted in heavy economic losses to agriculture forest and husbandry, and caused severe damage of ecosystem equilibrium in the invasion areas. The control to Crofton weed is imperative. Currently, the control of Procecidochares utilis Stone (an introduced host specific stem gall fly of Crofton weed，which was safe to other plants) to Crofton weed has showed the obvious effect. However, preliminary research suggested that P. utilis was threatened by contaminants in environment. Cadmium(Cd) stress can influence fecundity of P. utilis, accordingly reduced the effect of P. utilis for controlling the invasive weed -- E. adenophorum. This project intends to start from the individual level, organization level and cell level to research the effect of Cd on mating, and the passed path of Cd in the reproductive system, and the damage to genital system. Results of this project will enrich the biological effects of heavy metal pollution, and will lay a research foundation for make further explanation on mechanism of insect reproductive system injury caused by heavy metals contamination, and will provide theoretical guidance for laying feasibility method to increase biocontrol efficiency for control harmful species.

紫茎泽兰作为入侵性杂草遍及云南、贵州、广西、四川和西藏等省区，给大部分地区的农、林、牧、副业造成重大危害，对其进行防治和有效控制已经势在必行。泽兰实蝇专性寄生紫茎泽兰，对其他植物安全，对紫茎泽兰控制作用明显。但是泽兰实蝇在环境中经常受到污染物的威胁，如在矿区及重工业生产区均存在不同程度的镉污染，前期的研究工作表明，镉胁迫影响到了泽兰实蝇的生殖力，降低了泽兰实蝇对入侵性杂草紫茎泽兰的防治效果。本项目拟从个体水平、组织水平、细胞水平入手，研究镉对泽兰实蝇的交配行为及交配效应的干扰作用，及对泽兰实蝇生殖器官的损伤。本项目的研究结果将充实重金属污染的生物学效应，为进一步阐释重金属镉对昆虫生殖系统的毒性损伤机理奠定基础；为提高重金属污染区外来有害物种生物防治效率可行性方法的制定提供理论指导。

入侵性杂草紫茎泽兰的危害性重大，其专性天敌泽兰实蝇具有极佳的控制潜能。然而在重金属镉污染区泽兰实蝇的生殖力低下，本项目从个体水平、组织水平、细胞水平入手，研究镉对泽兰实蝇的交配效应的干扰作用、生殖器官损伤后的变化，探讨镉胁迫降低泽兰实蝇防控紫茎泽兰效果的生殖生物学机理。研究结果表明，镉胁迫后，在个体水平上，染镉使泽兰实蝇成虫的性成熟日期推迟，降低了雄虫的交配能力，令雌虫寿命以及再交配后的寿命缩短，卵巢含卵量下降，降低了雄虫对雌虫信息素的敏感程度，雄虫受处理的浓度高则与其交配过的雌虫的再交配能力强；在组织水平上，染镉后泽兰实蝇成虫的精巢、雄性附腺、卵巢的长宽均显著缩短，生殖腺系数变小，镉在生殖系统中主要积累于精巢中，卵巢和雄性附腺次之。雌虫在交配时会接受来自雄虫传递来的镉，而且可将镉从母代传递给子代；在细胞水平上，染镉后卵巢、精巢、雄性附腺均产生了一系列不良的改变，如微绒毛变细、断裂、边缘崩裂，细胞器空泡化，线粒体模糊、嵴消失，粗面内质网解体、核糖体散落，细胞核变形等；在分子水平上，测定并分析了泽兰实蝇的转录组数据，为今后从基因组学方面开展重金属胁迫泽兰实蝇的相关研究打下基础。本研究结果能充实重金属污染的生物学效应，为进一步阐析重金属对动物生殖系统的毒性损伤机理奠定基础，具有重要的理论价值。